ArticlePDF Available
2012
AUSDIAB
THE AUSTRALIAN
DIABETES, OBESITY AND
LIFESTYLE STUDY
02 AUSDIAB 2012
TABLE OF CONTENTS
Copyright © 2013 by Baker IDI Heart and Diabetes Institute
ISBN: 0-9578310-3
Published: Baker IDI Heart and Diabetes Institute
Design and layout: Dynamic Creations, Victoria, Australia
AUTHORS
SK Tanamas, DJ Magliano, B Lynch, P Sethi, L Willenberg, KR Polkinghorne, S Chadban, D Dunstan, JE Shaw
SPONSORS
The AusDiab study, co-ordinated by Baker IDI Heart and Diabetes Institute, gratefully acknowledges
the generous support given by:
National Health and Medical Research Council (NHMRC)
Australian Government Department of Health and Ageing
Abbott Australasia
Alphapharm
AstraZeneca
Australian Institute of Health and Welfare
Australian Kidney Foundation
Aventis Pharmaceutical
Bio-Rad Laboratories
Bristol-Myers Squibb Pharmaceuticals
City Health Centre-Diabetes Service-Canberra
Department of Health – New South Wales
Department of Health – South Australia
Department of Health – Western Australia
Department of Health and Community Services -
Northern Territory
Department of Health and Human Services – Tasmania
Department of Human Services – Victoria
Department of Human Services – South Australia
Diabetes Australia
Diabetes Australia (Northern Territory)
Eli Lilly Australia
Estate of the Late Edward Wilson
GlaxoSmithKline
Impeto Medical
Jack Brockhoff Foundation
Janssen-Cilag
Kidney Health Australia
Marian & FH Flack Trust
Menzies Research Institute, Hobart
Merck Lipha s.a.
Merck Sharp & Dohme
Novartis
Novo Nordisk
Pfizer
Pharmacia and Upjohn
Pratt Foundation
Roche Diagnostics
Royal Prince Alfred Hospital, Sydney
Sanofi Aventis
Sanofi Synthelabo
Servier Laboratories
Queensland Health
Tasmanian Department of Health and Human Services
Victorian Government’s OIS Program
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AUSDIAB 2012
TABLE OF CONTENTS
BACKGROUND
1:
03
AUSDIAB 2012
TABLE OF CONTENTS
Foreword 04
Executive Summary 05
1: Background 07
2: Diabetes and pre-diabetes 09
3: Obesity 17
4: Blood pressure 25
5: Metabolic syndrome 33
6: Chronic Kidney Disease 39
7:
Physical activity and sedentary behavior
47
8: Mortality 55
9: Survey methods 59
10: Response rates 65
Appendix A: Testing sites and dates 70
Appendix B: Summary tables 72
Appendix C: Abbreviations 89
Appendix D: Contributors 90
TABLE OF
CONTENTS
Suggested citation: Tanamas SK, Magliano DJ, Lynch B, Sethi P, Willenberg L, Polkinghorne KR, Chadban S, Dunstan D, Shaw JE. AusDiab 2012.
The Australian Diabetes, Obesity and Lifestyle Study. Melbourne: Baker IDI Heart and D iabetes Institute 2013.
04 AUSDIAB 2012
TABLE OF CONTENTS
In addition to reporting on disease prevalence, AusDiab has also
made major contributions to the understanding of risk factors,
such as physical activity and sedentary behaviour. These risk
factors are increasingly recognised as being related to a wide
array of chronic conditions, not just diabetes and obesity.
The International Diabetes Federation (IDF), which represents
the needs of people with diabetes around the world, is a
strong supporter of research into the burden of the disease,
and the IDF provides regular country-by-country data in its
Diabetes Atlas.
It is noteworthy that AusDiab, and its lead investigators,
Jonathan Shaw and Paul Zimmet, have contributed significantly
to the Atlas, providing data, analysis and insights that improve
our understanding of the global impact of diabetes. Investigating
how diseases influence populations as a whole, and across
social and ethnic strata, is essential for the improvement of the
health of our world, and the contribution of AusDiab to this has
been impressive.
With the current report on the 12-year outcomes of the
study, AusDiab makes two further important steps. First,
it considerably extends the period of observation of the
cohort beyond the five years that had been achieved earlier.
This means that the impact of asymptomatic risk factors
identified in 1999 can be measured over a time period that
is relevant to the gradual development of conditions such
as diabetes, heart and kidney disease.
Second, the AusDiab team has taken the opportunity of
adding measures of cognitive function and physical disability
to the assessments. This recognises the increasing impact of
these factors on day-to-day life in an ageing population, and
allows the exploration of their links with chronic diseases such
as diabetes.
The AusDiab study has already produced over 130
peer-reviewed scientific publications on diabetes, obesity,
heart and kidney disease and their risk factors. This third
wave of AusDiab will no doubt continue to inform healthcare
professionals and providers about the size of the problem
that is faced, and the ways in which interventions can be
developed and targeted.
Although originally planned to describe the burden of diabetes
in Australia, the vision of the AusDiab team over 12 years has
produced advancements in knowledge that are relevant on a
global scale.
Sir Michael Hirst
President, International Diabetes Federation
INTERNATIONAL DIABETES FEDERATION
FOREWORD
04 AUSDIAB 2012
FOREWORD
In the 1990s, Professors Paul Zimmet and Timothy Welborn identified a crucial gap in the
understanding of diabetes and related conditions in Australia, and developed the idea for a
national survey. The Australian Diabetes, Obesity and Lifestyle (AusDiab) study commenced
in 1999, and rapidly established itself on the international stage as one of the premier
epidemiological studies of diabetes anywhere in the world.
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FOREWORD
BACKGROUND
1:
05
AUSDIAB 2012
EXECUTIVE SUMMARY
The Australian Diabetes, Obesity and Lifestyle study (AusDiab)
is the first national Australian longitudinal population-based
study to examine the prevalence and incidence of diabetes
and its complications, as well as high blood pressure, heart
disease and kidney disease.
Identified as being the only national study of its kind to have
been undertaken in a developed nation, the AusDiab study
began in 1999-2000, when over 11,000 adults across the
country took part in the study. These individuals were invited
to take part in two follow-up studies, the first in 2004-2005,
and the second in 2011-2012.
The 1999–2000 baseline survey collected information
about diabetes, cardiovascular disease, obesity and kidney
disease, and about risk factors for each of these conditions.
The baseline survey enabled the measurement of the number
of Australians with these diseases or risk factors at that point
in time. It provided an estimate of how many people in Australia
had diabetes and other conditions in 1999–2000.
The two follow-up surveys, undertaken five and 12 years after
the baseline study, have provided the opportunity to investigate
the number of new cases (incidence) arising in the Australian
population for each of these conditions. This is possible
because people who came to the baseline survey have been
followed-up to investigate who did and did not develop these
conditions. The most recent follow-up in 2011-2012 added
measures of cognitive function and physical disability.
This report presents the main findings from the AusDiab
12-year follow-up based on data collected from people who
participated in both the 1999–2000 baseline survey and at
least one of the two follow-up surveys.
Annual incidence was estimated from the number of individuals
developing each of the diseases and risk factors studied over
the 12-year period between surveys.
The findings with
respect to the key matters of interest are
presented in separate chapters focusing on: disorders of
glucose tolerance; weight and obesity status; blood pressure;
the metabolic syndrome; kidney disease; and physical activity.
The final chapter presents
total mortality data over a 12-year
period for the various diseases and risk factors.
DIABETES
Every year, 0.7% of adults developed diabetes.
Those who were in the high-risk category of the AUSDRISK
score were 16 times more likely to develop diabetes than
those in the low-risk group.
Living in the most socially-disadvantaged areas of Australia
doubled the risk of developing diabetes.
Having diabetes almost doubled the chances of being
admitted to hospital and of requiring multiple visits to a GP.
Among those aged 60 years and over, people with diabetes
were more likely to have cognitive impairment and physical
disability than those without diabetes.
Diabetes mellitus has become one of the most common non-communicable diseases in the world.
It results in substantial morbidity and mortality, primarily from cardiovascular complications,
eye and kidney diseases and limb amputations. It now represents one of the most challenging
public health problems of the 21st century.
Australia is a nation that provides a high proportion of its population with the opportunities for
good health. Life expectancy is high, but modernization and industrialization have led to
a reduction in physical activity and an increase in the consumption of energy-rich foods.
Consequently, lifestyle diseases such as type 2 diabetes are increasing rapidly, and leading
to an array of adverse outcomes.
EXECUTIVE SUMMARY
06 AUSDIAB 2012
EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
OBESITY
Over 12 years, the average gain in waist circumference
was 5.3 cm, and was greater in women than in men.
Younger people gained more weight and waist
circumference compared to those who were older.
Depression was nearly twice as common among those
with obesity compared to those who were not obese.
Among those aged 60 and over, people with obesity were
approximately twice as likely to have cognitive impairment
and physical disability as were those without obesity.
BLOOD PRESSURE
Every year, 3% of adults developed high blood pressure.
The risk of developing high blood pressure was 1.0%
per year for people aged 25–34 years and increased to
7.3% per year for people aged 65–74 years.
The risk of developing high blood pressure was greater for
people with pre-diabetes and diabetes, and for those who
were overweight or obese.
Among smokers, the risk of developing hypertension was
approximately 50% greater in men compared to women.
METABOLIC SYNDROME
The incidence of the metabolic syndrome rose with age,
peaking among those aged 65 and over.
Having diabetes and pre-diabetes increased the risks of
developing the metabolic syndrome.
Among those aged 60 and over, people with the metabolic
syndrome were more likely to have cognitive impairment
and physical disability than were those without the
metabolic syndrome.
KIDNEY DISEASE
Every year, 0.4% of adults developed chronic kidney
disease as defined by a reduction in kidney function
(impaired glomerular filtration rate).
Every year, 0.7% of adults developed evidence of early
kidney damage as shown by the leakage of albumin into
the urine (albuminuria).
Having high blood pressure and diabetes were key risk
factors for developing kidney disease.
Having signs of kidney disease approximately doubled
the chances of being admitted to hospital and of requiring
multiple visits to a GP.
Among those aged 60 and over, people with signs of
kidney disease were more likely to have cognitive
impairment and physical disability than were those
without normal kidney function.
MORTALITY
Over 12 years, people with previously known diabetes were
nearly five times as likely to die compared to people with
normal glucose tolerance.
People with previously known diabetes have a similar risk
of mortality to smokers.
Kidney disease, cardiovascular disease and high blood
pressure were associated with an increased mortality risk.
CONCLUSION
The AusDiab study has now been tracking the health of
the nation for 12 years. The most recent findings show that
diabetes, obesity, high blood pressure and kidney disease all
remain major challenges. AusDiab has confirmed that simple
risk factors can often be used to identify those most at risk
of developing these conditions.
The AUSDRISK tool, which was designed to be used by the
public as well as by health care professionals, is a powerful
way of identifying people at risk of developing type 2 diabetes.
The increasing recognition that social disadvantage plays an
important role in the development of chronic disease extends
the types of preventive interventions beyond the strictly
medical to those in the social and political arenas.
AusDiab has demonstrated that the impact of these chronic
conditions can be seen at many levels. This includes the
increased mortality risks, the extra costs of delivering health
care and the associated, and sometimes devastating, effects
of cognitive impairment and physical disability. The broadening
array of outcomes associated with diabetes and its related
conditions further strengthens the need to improve prevention,
screening, diagnosis and treatment.
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DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
BACKGROUND
1:
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BACKGROUND
8AUSDIAB 2012
BACKGROUND
BACKGROUND
1:
The key findings included the following:
the prevalence of diabetes was 7.4%;
the number of people with diabetes had more than doubled
since 1981;
a further 16.3% had pre-diabetes – either impaired glucose
tolerance or impaired fasting glucose;
60% were overweight or obese;
6.6% had dyslipidaemia;
2.5% had proteinuria, 6.4% had haematuria and 1.7%
had renal impairment.
In 2004, the participants from the initial baseline study were
invited to return for a repeat examination. The main aim of
this five-year follow-up was to estimate the incidence of key
conditions, and to look for factors that placed individuals at
higher risk of developing certain key conditions.
The main findings from the second, follow-up, phase of
AusDiab included the following:
approximately 275 adults develop diabetes every day in
Australia;
the AUSDRISK score was developed to identify people at
highest risk of developing type 2 diabetes;
increasing time spent watching television was associated
with increased mortality over 7 years;
increase in weight and waist circumference was more rapid
in younger than older adults;
people who were obese were six times more likely to develop
the metabolic syndrome than were those of normal weight;
every year, almost 1.0% of adults develop reduced kidney
function or leakage of albumin into the urine.
In 2011, the third phase of AusDiab was commenced. Once
again, all participants, who took part in the baseline study were
invited for repeat testing. On this occasion, the study expanded
beyond the assessments included in the two earlier phases.
Measurement of cognitive function, disability and physical
function were included, as dementia and physical frailty are
becoming increasingly important in the burden of disease.
Sub-groups of participants were also invited to have more
detailed measurements of blood pressure and physical activity.
This involved having a blood pressure cuff fitted to allow 24-hour
ambulatory monitoring of blood pressure, and the wearing of an
accelerometer and inclinometer to objectively measure physical
activity throughout a seven-day period.
The results of the third phase are presented in this report.
Results presented in each chapter are unadjusted, and
therefore inform mainly about disease burden. Appendix B
provides 95% confidence intervals for all these results, and
also age- and sex-adjusted comparisons.
WHAT IS THE DIFFERENCE BETWEEN
PREVALENCE AND INCIDENCE?
When investigating the patterns of disease within a population
it is useful to describe both the prevalence and the incidence
of a condition.
Prevalence
The proportion of people within a population who have a certain
disease or condition at a particular point in time. This is usually
expressed as a percentage.
Incidence
The number of new cases of a condition or disease that
develop over a period of time, among those who are initially
free of the condition or disease. This is usually expressed as
a rate, e.g. 3 per cent per year.
It is important to note that while the baseline AusDiab study
was ideal for estimating disease prevalences, which can be
extrapolated to the general community, the follow-up phases
are not, because new independent study samples are required
to track the community prevalence of diseases over time.
Within this report, the percentage of the AusDiab population
with various conditions at the three time-points are presented
in order to describe how these percentages change as people
age. Thus, comparing baseline with the 2011/12 data informs
about changes that occur as the AusDiab population aged by
12 years, but does not directly inform us about how the general
population of Australia has changed over that time period.
The Australian Diabetes, Obesity and Lifestyle study (AusDiab) is the first national, Australian,
longitudinal population-based study established to examine the prevalence and incidence of
diabetes and its complications, as well as heart disease and kidney disease. The study began in
1999, when 11,247 adults (aged 25 years and above) were recruited from the general community.
Six locations were randomly selected in each of the six states and in the Northern Territory, and
within each of these 42 locations, all adults were invited to take part. Participants underwent
physical examinations, blood and urine testing, and provided extensive information on their diet,
physical activity levels and other lifestyle parameters. This ‘baseline’ examination produced
estimates of the prevalence of disease that were applicable to the national population.
1:
BACKGROUND
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DIABETES AND
PRE-DIABETES
2:
DIABETES AND
PRE-DIABETES
2:
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10 AUSDIAB 2012
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DIABETES AND
PRE-DIABETES
2:
DIABETES AND PRE-DIABETES
The diagnostic criteria for diabetes, impaired glucose tolerance
(IGT) and impaired fasting glucose (IFG) were based on the
values for venous plasma glucose concentration (fasting
and two-hour measurements) outlined in the World Health
Organization report on the Diagnosis and Classification of
Diabetes Mellitus (Table 2.1)1.
People who reported taking oral hypoglycaemic medication
or insulin were classified as having diabetes regardless of their
plasma glucose levels. The term ‘pre-diabetes’ is used to
include all those with either IFG or IGT. In this report, results for
type 1 and type 2 diabetes have not been reported separately,
as the vast majority of cases were classified as type 2.
Table 2.1: Classification values for the oral glucose
tolerance test
INCIDENT DIABETES
New (incident) cases of diabetes were defined as individuals who
had either normal glucose tolerance (NGT), IFG or IGT at baseline,
but had developed diabetes at follow-up in 2004-05 or 2011-12.
INCIDENT CASES OF IMPAIRED
FASTING GLUCOSE AND IMPAIRED
GLUCOSE TOLERANCE
New (incident) cases of IFG were defined as: (i) people who
had NGT at baseline, but had developed IFG at follow-up in
2004-05, and had neither regressed to NGT nor progressed
to IGT or diabetes at follow-up in 2011-12; or (ii) people who
had NGT at baseline and at follow-up in 2004-05, but had
developed IFG at follow-up in 2011-12.
There were 42 people who had NGT at baseline and
developed IFG at follow-up in 2004-05, but regressed to
NGT at follow-up in 2011-12, and 34 people who had NGT
at baseline, but developed IFG at follow-up in 2004-05 and
further progressed to IGT or diabetes at follow-up in 2011-12.
These people were not included as incident IFG cases.
New (incident) cases of IGT were defined as: (i) people
who had NGT or IFG at baseline, but had developed IGT at
follow-up in 2004-05, and had neither regressed to NGT or
IFG nor progressed to diabetes at follow-up in 2011-12; or
(ii) people who had NGT or IFG and baseline and at follow-up
in 2004-05, but had developed IGT at follow-up in 2011-12.
There were 95 people who had NGT or IFG at baseline and
developed IGT at follow-up in 2004-05, but reverted to NGT or
IFG at follow-up in 2011-12, and 35 people who had NGT or
IFG at baseline, but developed IGT at follow-up in 2004-05
and further progressed to diabetes at follow-up in 2011-12.
These people were not included as incident IGT cases.
The term diabetes mellitus describes a metabolic disorder with multiple causes characterized by chronically
elevated blood glucose levels (hyperglycaemia), with disturbances of carbohydrate, fat and protein
metabolism. The effects of diabetes include long-term damage, dysfunction and failure of various organs
and tissues. It predisposes those suffering from it to many severe conditions, including cardiovascular
disease, visual loss, amputations and renal failure.
Diabetes is a disease with mixed aetiology. There are many risk factors for the development of the disease,
including obesity, hypertension and sedentary lifestyle, many of which are also risk factors for cardiovascular disease.
This chapter presents: (i) the incidence (% per year) and trends in the percentage of the population with
diabetes, (ii) the impact of various risk factors on the development of diabetes, (iii) the relationship of depression,
cognitive impairment, and disability with glucose tolerance, (iv) trends in metabolic targets for diabetes control
and the use of treatment and medication in diabetes, and (v) healthcare utilization in diabetes.
2:
DIABETES AND
PRE-DIABETES
DEFINITIONS
PLASMA GLUCOSE (MMOL/L)
Diabetes 7.0 or 11.1
Impaired glucose
tolerance (IGT) <7. 0 and 7. 8 -11 . 0
Impaired fasting
glucose (IFG) 6.1-6.9 and < 7. 8
Normal glucose
tolerance (NGT) < 6 .1 and <7. 8
All participants on oral hypoglycaemic medication or insulin were
classified as having diabetes.
Fasting
glucose
2-hour
glucose
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DIABETES AND
PRE-DIABETES
2:
RESULTS
INCIDENCE OF DIABETES AND
PRE-DIABETES
The overall incidence (% per year) of diabetes is shown in
Figure 2.1, and indicates that there were slightly more new
cases of diabetes in men than in women.
A similar pattern of diabetes incidence is observed when
diabetes is defined using HbA1c 6.5%, although the overall
numbers are slightly lower. Using HbA1c, the annual incidence
of diabetes is 0.6% and 0.4% in men and women, respectively.
FIGURE 2.1: Annual incidence of diabetes according to
sex: the AusDiab study
0.0
0.2
0.4
0.6
0.8
Incidence (% per year)
0.8
0.7
0.6
Men Women All
The heights of bars on all graphs are accurate to two decimal places,
but data labels are rounded to one decimal place.
The annual incidence of diabetes increased with age, peaking
between the ages of 65 and 74 years, and then decreased
after the age of 75 years. For men, the incidence of diabetes
increased with age until it plateaued after the age of 55 years,
before decreasing after the age of 75 years. For women, the
incidence of diabetes increased with age, peaking between the
ages of 65 and 74 years, and then decreased after the age of
75 years (Figure 2.2)
.
FIGURE 2.2: Annual incidence of diabetes according to
baseline age: the AusDiab study
0.0
0.4
0.8
1.2
Baseline age (years)
Incidence (% per year)
Men Women All
25-34 0.3 0.3 0.3
35-44 0.4 0.2 0.3
45-54 0.7 0.7 0.7
55-64 1. 3 0.6 0.9
65 - 74 1.3 1. 3 1. 3
75+ 0.8 1. 0 0.9
Men
Women
All
25-34 35-44 45-54 55-64 65-74 75+
The annual incidence of diabetes among those with NGT, IFG
and IGT at baseline is shown in Figure 2.3. In both men and
women, the incidence of diabetes in those with IFG and IGT
at baseline was 7-14 times higher than in those with NGT.
FIGURE 2.3: Annual incidence of diabetes according to
baseline glucose tolerance status: the AusDiab study
0.0
1.0
2.0
3.0
4.0
Incidence (% per year)
0.3
2.0
3.5
0.2
2.8 2.6
0.3
2.2
3.0
Baseline glucose tolerance status
Men Women All
NGT IFG IGT
NGT – normal glucose tolerance; IFG – impaired fasting glucose;
IGT – impaired glucose tolerance.
The Australian Diabetes Risk Assessment Tool (AUSDRISK) was
developed as a tool to assess 5-year risk of developing diabetes.
Compared to those who were scored in the ‘low risk’ category,
the annual incidence of diabetes in those in the ‘intermediate risk‘
category and those in the ‘high risk’ category were approximately
4 times and 16 times higher, respectively (Figure 2.4).
12 AUSDIAB 2012
DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
FIGURE 2.4: Annual incidence of diabetes by AUSDRISK
score: the AusDiab study
0.0
0.4
0.8
1.2
1.6
Incidence (% per year)
0.1
0.4
1.5
0.1
0.3
1.7
0.1
0.4
1.6
AUSDRISK
Low risk
Intermediate risk
High risk
Men Women All
Low risk: AUSDRISK score 5; intermediate risk: AUSDRISK score
6–11; High risk: AUSDRISK score 12.
The annual incidence of both IFG and IGT were greater in men
than in women. The annual incidence of IFG in men was twice
as high as the annual incidence in women (Figure 2.5).
FIGURE 2.5: Annual incidence of impaired fasting glucose
and impaired glucose tolerance: the AusDiab study
Men Women All
0.0
0.2
0.4
0.6
0.8
1.0
Incidence (% per year)
0.9
0.6
0.8
0.3
0.9
0.4
IGT IFG
IFG – impaired fasting glucose; IGT – impaired glucose tolerance.
RISK FACTORS FOR DIABETES
Obesity
Compared to those with a body mass index (BMI) in the
normal range at baseline, the annual incidence of diabetes was
approximately 2 and 5 times higher among those classified as
overweight and obese, respectively. Men who were overweight
or obese at baseline had a higher annual incidence of diabetes
than did overweight or obese women. Both men and women
who were classified as obese at baseline had at least double
the annual incidence of diabetes compared to those who were
overweight at baseline (Figures 2.6).
The incidence of diabetes in those with a high risk waist
circumference at baseline was 3 times higher compared
to those with a low risk waist circumference at baseline.
The incidence of diabetes for both those with low risk and
high risk waist circumference at baseline was higher in men
than in women (Figure 2.6).
FIGURE 2.6: Annual incidence of diabetes according to
baseline BMI and baseline waist circumference status:
the AusDiab study
Men Women All
0.0
0.0
0.4
0.4
0.8
0.8
1.2
1.2
1.6
1.6
Incidence (% per year)Incidence (% per year)
0.3
0.7
1.7
0.3
0.6
1.3
0.3
0.6
1.5
Baseline BMI status
Baseline waist circumference status
Normal
Overweight
0.3
1.1
0.2
0.9
0.3
0.9
Low risk High risk
Obese
BMI: (i ) normal: <25 kg/m2; (ii) overweight: 25-29.9 kg/m2; and
(iii) obese: 30 kg/m2. Waist: (i ) low risk: <94 cm for Europid men,
<90 cm for Aboriginal/Torres Strait Islander, Asian and South
European men, <80 cm for women; (ii) high risk: 94 cm for Europid
men, 90 cm for Aboriginal/Torres Strait Islander, Asian and South
European men, 80 cm for women.
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DIABETES AND
PRE-DIABETES
2:
Physical activity
The annual incidence of diabetes increased in those who
reported being inactive or reported doing insufficient physical
activity at baseline compared to those who reported sufficient
levels of physical activity. At all levels of physical activity
reported at baseline, the annual incidence was greater in men
than in women (Figure 2.7).
FIGURE 2.7: Annual incidence of diabetes according to
baseline physical activity: the AusDiab study
0.0
0.4
0.8
1.2
Incidence (% per year)
1.1
0.9
0.6
1.0
0.6
0.4
1.0
0.7
0.5
Baseline physical activity categories
Inactive
Insufficient
Sufficient
Men Women All
‘Physical activity time’ for the previous week was calculated as the sum
of the time spent performing moderate activity (e.g. walking) plus double
the time spent in vigorous activity (to reflect its greater intensity). Inactive:
no physical activity in the previous week; insufficient: 1-149 minutes
of physical activity in the previous week; sufficient: 150 minutes of
physical activity in the previous week.
Hypertension
The annual incidence of diabetes was approximately three times
greater in those with high blood pressure at baseline compared
to those with normal blood pressure at baseline (Figure 2.8).
FIGURE 2.8: Annual incidence of diabetes according to
baseline hypertension status: the AusDiab study
Men Women All
0.0
0.4
0.8
1.2
1.6
Incidence (% per year)
0.5
1.4
0.4
1.1
0.4
1.3
Baseline hypertension status
Normal Hypertension
Index of remoteness
The annual incidence of diabetes did not greatly differ by
Accessibility/Remoteness Index of Australia (ARIA). In all areas,
men had a higher annual incidence of diabetes compared to
women (Figure 2.9).
FIGURE 2.9: Annual incidence of diabetes according to
geographic remoteness of residence*: the AusDiab study
Men Women All
0.0
0.2
0.4
0.6
0.8
Incidence (% per year)
0.8 0.7 0.7
0.6
0.4
0.7
0.7
0.6
0.7
Baseline ARIA status
Major city
Inner regional
Outer regional/
Remote/
Very remote
ARIA: Accessibility/Remoteness Index of Australia.
*measured based on postcode of residence
Index of relative socioeconomic disadvantage
The annual incidence of diabetes decreased by relative index of
socio-economic disadvantage. People who lived in areas that were
more socio-economically disadvantaged (1st quintile) had a higher
annual incidence of diabetes compared to those who lived in less
socio-economically disadvantaged areas (5th quintile) (Figure 2.10).
FIGURE 2.10: Annual incidence of diabetes according to
baseline socio-economic disadvantage*: the AusDiab study
0.0
0.4
0.8
1.2
Incidence (% per year)
Men Women All
1st 1.1 0.9 1.0
2nd 0.9 0.6 0.7
3rd 0.6 0.7 0.7
4th 0.7 0.5 0.6
5th 0.7 0.4 0.5
Quintiles of index of relative socio-economic disadvantage
1st 2nd 3rd 4th 5th
Men
Women
All
*measured based on postcode of residence.
14 AUSDIAB 2012
DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
PERCENTAGE OF THE POPULATION
WITH DIABETES
The percentage of the population with diabetes at the three
time points is shown in Figure 2.11. As the population aged
over the 12 years, this percentage rose from 8.5% to 12.0%.
At each time point, the percentage with diabetes was higher
in men than women.
FIGURE 2.11: Trends in the percentage of the population
with diabetes in 1999-2000, 2004-05 and 2011-12
according to sex: the AusDiab study
0
4
8
16
Percentage (%)
9.9
7.3
8.5
11.1
7.7
9.3
14.8
9.8
12.0
Men
Women
All
12
1999-2000 2004-05 2011-12
Data have not been standardised for age
.
DEPRESSION AND DIABETES
The prevalence of depression according to glucose tolerance
status is presented in Figure 2.12. The prevalence of depression
was 65% higher in those with diabetes compared to those
without diabetes.
FIGURE 2.12: Prevalence of depression in 2011-12
according to glucose tolerance status in 2011-12:
the AusDiab Study
0
4
8
12
16
Prevalence (%)
9.8
16.2
11.8
No diabetes
Pre-diabetes Diabetes
Data have not been standardised for age.
Pre-diabetes includes people with impaired glucose tolerance (IGT)
or impaired fasting glucose (IFG).
COGNITIVE IMPAIRMENT AND DIABETES
The prevalence of cognitive impairment among people aged
60 and over according to glucose tolerance status is presented
in Figure 2.13. Compared to people with no diabetes, the
prevalence of cognitive impairment in those with diabetes was
more than double.
FIGURE 2.13: Prevalence of cognitive impairment in
2011-12 according to glucose tolerance status in 2011-12
among people aged 60 and over: the AusDiab Study
0
2
4
6
8
Prevalence (%)
3.4
8.2
5.5
No diabetes
Pre-diabetes Diabetes
Data have not been standardised for age.
Pre-diabetes includes people with impaired glucose tolerance (IGT)
or impaired fasting glucose (IFG).
DISABILITY AND DIABETES
The prevalence of disability in people aged 60 years increased
according to glucose tolerance status. The prevalence was
highest
in those with diabetes and lowest in those without
diabetes (Figure 2.14).
FIGURE 2.14: Prevalence of disability in 2011-12
according to glucose tolerance status in 2011-12 among
people aged 60 years and over: the AusDiab Study
0
10
20
30
40
Prevalence (%)
27.7
43.6
33.3
No diabetes
Pre-diabetes Diabetes
50
Data have not been standardised for age.
Pre-diabetes includes people with impaired glucose tolerance (IGT)
or impaired fasting glucose (IFG).
15
AUSDIAB 2012
DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
METABOLIC TARGETS FOR
DIABETES CONTROL
The percentage of people with diagnosed diabetes who were
meeting the recommended low-density lipoprotein (LDL)
cholesterol target of less than 2.59 mmol/L was 3.4 times higher
at follow-up in 2011-12, compared to baseline (Figure 2.15).
The percentage of people with diagnosed diabetes who were
meeting the recommended blood pressure of less than 130/80
mmHg increased between baseline and follow-up in 2004-05,
but decreased between follow-up in 2004-05 and in 2011-12
(Figure 2.15).
A similar pattern was observed for HbA1c where the percentage
of people with diagnosed diabetes who were meeting the
recommend HbA1c target of less than 7.0% increased between
baseline and follow-up in 2004-05, but decreased between
follow-up in 2004-05 and in 2011-12 (Figure 2.15).
FIGURE 2.15: Percentage of people with diabetes who
meet metabolic targets for diabetes control in 1999-2000,
2004-05 and 2011-12: the AusDiab study
0
20
40
60
80
Proportions meeting targets (%)
21.4 23.4
54.0
48.5
35.5
61.0
73.3
27.4
55.6
1999-2000 2004-05 2011-12
Metabolic targets
LDL
<2.59 mmol/L
BP
<130/80 mmHg
HbA1c
<7.0%
Data have not been standardised for age.
TREATMENT AND MEDICATION USE
Among those with diabetes, the percentage of people using
antihypertensive medication and cholesterol lowering agents
has increased since baseline. Compared to baseline, the
percentage of people with diabetes using antihypertensive
medication at follow-up in 2011-12 had increased by
approximately 37%, while the percentage of people with
diabetes using cholesterol-lowering agents at follow-up in
2011-12 increased by 76% (Figure 2.16).
FIGURE 2.16: The use of antihypertensive medication
and cholesterol-lowering agents in people with diabetes
in 1999-2000, 2004-05 and 2011-12: the AusDiab study
0
20
40
60
Percentage (%)
46.5
34.2
59.2
53.1
63.9
60.2
Antihypertensives Cholesterol
lowering agents
1999-2000 2004-05 2011-12
Data have not been standardised for age.
The percentage of people with diabetes who manage their
diabetes by diet only had decreased by almost 65% between
baseline and 2011-12. However, the percentage of people
with diabetes who use tablets and insulin had increased
between baseline and 2011-12 (Figure 2.17).
FIGURE 2.17: Use of treatments for diabetes in
1999-2000, 2004-05 and 2011-12: the AusDiab study
1999-2000 2004-05 2011-12
0
20
40
60
Percentage (%)
26.8
54.6
17.9
20.2
60.6
17.9
9.8
65.4
23.5
Diet only Tablets Insulin
+/- tablets
Data have not been standardised for age.
16 AUSDIAB 2012
DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
USE OF HEALTHCARE SERVICES
The number of visits to a general practitioner (GP) in the
previous 3 months was higher in those with diabetes compared
to those with pre-diabetes or those without diabetes. Among
those with diabetes, less than 10% of people had not seen a
GP in the previous 3 months, compared to more than 24%
of people with no diabetes or with pre-diabetes. Over 30% of
people with diabetes had seen a GP 3 times or more in the
previous 3 months, compared to only 16% and 17% of people
with no diabetes and pre-diabetes, respectively (Figure 2.18).
FIGURE 2.18: Number of visits to a general practitioner
in the previous 3 months according to glucose tolerance
status in 2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
17.4
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
No diabetes
Pre-diabetes Diabetes
100
3
visits
2
visits
1
visit
None
No diabetes 15.7 1 7. 8 35.0 31. 5
Pre-diabetes
17. 4 20.2 3 7. 8 24.6
Diabetes 3 1.2 23.4 35.6 9.9
3 visits
2 visits
1 visit
None
Data have not been standardised for age
.
Pre-diabetes includes people with impaired glucose tolerance (IGT)
or impaired fasting glucose (IFG).
The number of nights spent in a public or private hospital in
the previous 12 months was higher in those with diabetes
compared to those without diabetes or those with pre-diabetes.
Among those with diabetes, approximately 12% had spent
2 nights or more in a hospital in the previous 12 months,
compared to 6 - 7% of people without diabetes or with
pre-diabetes (Figure 2.19).
FIGURE 2.19: Number of nights spent in a hospital in the
previous 12 months according to glucose tolerance status
in 2011-12: the AusDiab study
3.8
6
83
5.1
12
7
90.2 89.9
3.1
0
20
40
60
80
Percentage (%)
No diabetes
Pre-diabetes Diabetes
100
2
nights
1
night
None
No diabetes 6.0 3.8 90.2
Pre-diabetes
7.0 3.1 89.9
Diabetes 12 .0 5 .1 83.0
2 nights
1 night
None
Data have not been standardised for age
.
Pre-diabetes includes people with impaired glucose tolerance (IGT)
or impaired fasting glucose (IFG).
REFERENCES
1
World Health Organization. Definition, Diagnosis and
Classification of Diabetes Mellitus and its Complications;
Part 1: Diagnosis and Classification of Diabetes Mellitus.
Geneva: Department of Noncommunicable Disease
Surveillance, WHO 1999.
17
AUSDIAB 2012
DIABETES AND PRE-DIABETES
DIABETES AND
PRE-DIABETES
2:
OBESITY
3:
AUSDIAB 2012
OBESITY 17
18 AUSDIAB 2012
OBESITY
OBESITY
3:
Overweight and obesity were defined using the World Health
Organization classification
3
for Europids based on BMI (weight
(kg)/height (m)
2
). Low risk and high risk waist circumference
(cm) were defined based on the International Diabetes
Federation (IDF) classification
4
.
While BMI (kg/m
2
) is used as a measure of overall adiposity
(Table 3.1), waist circumference is a more accurate measure
of central adiposity (Table 3.2).
Table 3.1: Body mass index classification
BODY MASS INDEX (KG/M2)
Normal <25.0
Overweight 25.0–29.9
Obese 30.0
Table 3.2: Classification of abdominal obesity by
waist circumference
WAIST CIRCUMFERENCE (CM)
Men Women
Europid Non-
Europid*
Europid Non-
Europid*
Low risk
<94.0 < 90.0 <80.0 <80.0
High risk
94.0 90.0 80.0 80.0
*Non-Europid defined as people of Aboriginal/Torres Strait, Asian
or South European origin.
INCIDENT OBESITY
New (incident) cases of obesity were defined as: (i) people
who were not obese (BMI <30 kg/m2) at baseline, but were
obese (BMI 30 kg/m
2
) at follow-up in 2011-12; or (ii) people
who were not obese at baseline but were obese at follow-up
in 2004-05 and did not attend follow-up in 2011-12.
Obesity is strongly linked to type 2 diabetes, and is a major risk factor not only for type 2 diabetes,
but other chronic conditions such as hypertension, cardiovascular disease,
dyslipidaemia, some
cancers and arthritis. The most serious form of obesity is the central (abdominal) rather than the
peripheral form, as it is associated with higher risks for
diabetes and cardiovascular disease 1, 2.
This chapter presents: (i) the changes in weight and waist circumference over 12 years, (ii) the
incidence (% per year) and trends in percentage of the population with obesity, (iii) the relationship of
depression, cognitive impairment, and disability with obesity, and (iv) healthcare utilization in obesity.
3:
OBESITY
DEFINITION
19
AUSDIAB 2012
OBESITY
OBESITY
3:
CHANGE IN WEIGHT AND WAIST
CIRCUMFERENCE
Over the follow-up period, there was an increase in average
weight and waist circumference in men and women (Figures
3.1 and 3.2).
For people aged 25-64 years at baseline, weight and waist
circumference increased over the 12 years of follow-up.
These increases became less with increasing age. In those
aged 65 years and older at baseline, weight decreased
while waist circumference increased. Those aged 25-34
years at baseline showed the greatest increase in weight
and waist circumference, compared to any other age group
(Figures 3.1 and 3.2).
On average, those aged less than 65 years at baseline showed
a weight increase of 3.2 kg, while those aged 65 years and
older at baseline showed a loss in weight of 2.4 kg. The weight
loss observed in the older age group may represent a loss of
muscle mass, as similar losses were not observed for waist
circumference over the same period (Figure 3.2).
Although the pattern of weight change was similar in men and
women, women aged 35 years and older at baseline had slightly
greater average weight changes than men. Thus, in people
aged 64 years and younger at baseline,
women gained slightly
more weight than men, whereas in people aged 75 years and
older at baseline, women lost slightly more weight than men
(Figure 3.1).
Figure 3.1: Mean weight change over 12 years according
to baseline age: the AusDiab study
0
-2
-4
4
8
Mean weight change (kg)
Men Women All
25-34 6.7 6.6 6.7
35-44 4.3 5.0 4.7
45-54 2.4 2.9 2.7
55-64 0.3 0.5 0.4
65 - 74 -2.1 - 2 .1 -2.1
75+ -4.2 -4.7 -4.5
All 2.3 2.9 2.6
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
Greater waist circumference changes were observed in younger
individuals compared with those who were older. On average,
the waist circumference increase was approximately 50%
greater in women than it was in men (Figure 3.2).
RESULTS
20 AUSDIAB 2012
OBESITY
OBESITY
3:
Figure 3.2: Mean waist circumference change over
12 years according to baseline age: the AusDiab study
4
2
0
6
8
Mean waist change (cm)
Men Women All
25-34 5.7 7. 3 6.6
35-44 5.3 7. 4 6.5
45-54 4.5 6.6 5.6
55-64 3.4 4.7 4 .1
65 - 74 2.1 3.4 2.7
75+ 0.6 1. 0 0.8
All 4.3 6.2 5.3
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
All BMI groups showed an increase in weight over the
follow-up period, with women generally gaining more weight
than men. The greatest mean weight increases were observed
in those who had a normal BMI at baseline, with lesser weight
gains observed in those who were initially overweight or obese
(Figure 3.3).
Figure 3.3: Mean weight change over 12 years according
to baseline body mass index status: the AusDiab study
0
1
2
3
4
Mean weight change (kg)
3.0
1.9
2.2
3.6
2.8
1.5
3.4
2.3
1.8
Baseline BMI status
Men Women All
Normal Overweight Obese
The heights of bars on all graphs are accurate to two decimal places,
but data labels are rounded to one decimal place.
Over the period of follow-up, an increase in waist
circumference was observed in all BMI groups. In men,
the increase in waist circumference was greatest in those
who were obese at baseline and smallest in those who
were overweight at baseline. However in women, the
increase in waist circumference was greatest in those
who were overweight at baseline, and smallest in those
who were obese at baseline (Figure 3.4).
Figure 3.4: Mean waist circumference change over
12 years according to baseline body mass index status:
the AusDiab study
0
2
4
6
8
Mean waist change (cm)
4.3 4.1 4.5
6.3 6.4
5.7
5.6
5.1 5.2
Baseline BMI status
Men Women All
Normal Overweight Obese
Change in weight over 12 years was greatest in those living in
outer regional/remote/very remote areas, compared to those
living in major cities and inner regional areas (Figure 3.5).
21
AUSDIAB 2012
OBESITY
OBESITY
3:
Figure 3.5: Mean weight change over 12 years according
to index of remoteness*: the AusDiab study
0
1
2
3
4
Mean weight change (kg)
1.9 1.9
3.2
2.8 2.8
3.3
2.4 2.4
3.3
Men Women All
Baseline ARIA
Major city
Inner regional
Outer regional/
Remote/
Very remote
ARIA= Accessibility/ Remoteness Index of Australia.
*measured based on postcode of residence.
In men, change in waist circumference over 12 years was
greater in those living in outer regional/remote/very remote areas,
compared to those living in major cities and inner regional areas.
However, in women, change in waist circumference over 12
years was greater in those living in major cities compared to inner
regional and outer regional/remote/very remote areas (Figure 3.6).
Figure 3.6: Mean waist circumference change over 12 years
according to index of remoteness: the AusDiab study
0
2
4
6
8
Mean waist change (cm)
4.2 4.0
4.6
6.8
6.2
5.2
5.6 5.2 4.9
Men Women All
Baseline ARIA
Major city
Inner regional
Outer regional/
Remote/
Very remote
ARIA= Accessibility/ Remoteness Index of Australia.
*measured based on postcode of residence.
The annual change in weight between baseline and follow-up in
2004-05 was greater than the annual change between follow-up
in 2004-05 and in 2011-12 (Figure 3.7).
The annual change in waist circumference was lower between
baseline and follow-up in 2004-05 compared to the change
in waist circumference between follow-up in 2004-05 and in
2011-12, particularly in men. In women, there was no difference
in annual change in waist circumference between baseline and
follow-up in 2004-05 and between follow-up in 2004-05 and in
2011-12 (Figure 3.7).
Figure 3.7: Difference in change in weight and change in
waist circumference between baseline and 2004-05, and
between 2004-05 and 2011-12: the AusDiab study
0.0
0.2
0.4
0.6
Annual change in weight (kg)
/waist (cm)
0.3
0.1
0.3
0.4
0.3
0.1
0.5 0.5
0.4 0.5
0.3
0.1
Baseline to 2004-05 2004-05 to 2011-12
Men
Annual change in
weight
Annual change in
waist
MenWomen WomenAll All
INCIDENCE OF OBESITY
The annual incidence of obesity is shown in Figure 3.8.
Compared to those with a normal BMI at baseline, those
classified as overweight had an approximate 26 times increased
risk of developing obesity. Of note, this is not because weight
gain did not occur in those whose BMI at baseline was normal
(Figure 3.3). For example, if a person had a BMI of 23 kg/m
2
,
and a weight of 68 kg, they would need to gain 21 kg weight
in order to reach the obesity cut-point of 30 kg/m
2
. Hence with
an average weight gain of 3.4 kg over 12 years, the chances
of becoming obese from normal would have been low.
The annual incidence of obesity in those who were overweight
at baseline was higher in women than in men (Figure 3.8).
22 AUSDIAB 2012
OBESITY
OBESITY
3:
Figure 3.8: Annual incidence of obesity according to
baseline body mass index status: the AusDiab study
0
1
2
3
4
Incidence (% per year)
0.1
2.2
1.3
0.2
3.2
1.3
0.1
2.6
1.3
Baseline BMI status
Men Women All
Normal Overweight All
For those who were normal or overweight at baseline, 28.4%
(1,044 out of 3,670) had progressed to a higher BMI category
during follow-up. For those who were obese at baseline, only
12.8% (114 out of 895) had moved to a lower BMI category
after 12 years (Table 3.3).
Table 3.3: Proportion of individuals classified by body
mass index in 2011-12 according to baseline body mass
index status: the AusDiab study
BMI STATUS
AT BASELINE
BMI STATUS IN 2011-12
nNormal
Overweight
Obese
Normal
1,8 4 9 1, 2 4 5 (67. 3 ) 575 (31.1) 29 (1.6 )
Overweight
1,8 21 18 2 (10.0 ) 1,199 (65.8) 4 40 ( 24.2)
Obese
895 7 (0.8 ) 107 (12.0) 781 ( 87. 3 )
Tot a l
4,565 1,4 3 4 1,88 1 1, 250
Data are n (%). Body mass index (BMI: weight ( kg)/height (m)2) was
categorized into three groups: (i) normal: <25 kg/m2; (ii) overweight:
25-29.9 kg/m2; and (iii) obese: 30 kg/m2
For those who had a low risk waist circumference at baseline,
46.6% (900 out of 1,933) had progressed to a high risk waist
circumference at follow-up. However, for those who had a high
risk waist circumference baseline, only 6.7% (177 out of 2,624)
had moved to a low risk waist circumference after 12 years
(Table 3.4).
Table 3.4: Proportion of individuals classified by waist
circumference categories in 2011-12 according to baseline
waist circumference categories: the AusDiab study
WAIST
CIRCUMFERENCE
CATEGORIES
AT BASELINE
WAIST CIRCUMFERENCE
CATEGORIES IN 2011-12
nLow risk High risk
Low risk 1,933 1,03 3 ( 5 3.4 ) 900 (46.6)
High risk 2,624 177 ( 6.7 ) 2,447 ( 93.3)
Tot a l 4,557 1,210 3 ,3 47
Data are n (%). Waist circumference: (i) low risk: < 94 cm for Europid
men, <90 cm for Aboriginal/Torres Strait Islander, Asian and South
European men, <80 cm for women; (ii) high risk: 94 cm for Europid
men, 90 cm for Aboriginal/Torres Strait Islander, Asian and South
European men, 80 cm for women.
PERCENTAGE OF THE POPULATION
WITH OBESITY
The percentage of the population who were obese at the
three time points is shown in Figure 3.9. As the population
aged over the 12 years, this percentage rose from 22.3% to
27.3%. At each time point, the percentage with obesity was
higher in women than in men.
Figure 3.9: Trends in the percentage of the population
with obesity in 1999-2000, 2004-05 and 2011-12 according
to sex: the AusDiab study
0
10
20
30
Percentage (%)
20.8
23.6 22.3
26.0 27.5 26.8
27.0 27.5 27.3
Men
Women
All
1999-2000 2004-05 2011-12
Data have not been standardised for age.
23
AUSDIAB 2012
OBESITY
OBESITY
3:
DEPRESSION AND OBESITY
The prevalence of depression was similar in people with
a normal BMI and those who were overweight. However,
compared to people with a normal BMI and people who were
overweight, the prevalence of depression in those who were
obese was approximately 80% higher (Figure 3.10).
Figure 3.10: Prevalence of depression in 2011-12
according to BMI status in 2011-12: the AusDiab study
0
4
8
12
16
Prevalence (%)
8.6
16.1
8.9
Normal Overweight Obese
Data have not been standardised for age.
COGNITIVE IMPAIRMENT AND OBESITY
The prevalence of cognitive impairment in people aged 60 years
and over was almost double among people who were obese
compared to people with a normal BMI (Figure 3.11).
Figure 3.11: Prevalence of cognitive impairment in
2011-12 according to BMI status in 2011-12 among
people aged 60 and over: the AusDiab Study
0
2
4
6
Prevalence (%)
2.8
5.5
4.9
Normal Overweight Obese
Data have not been standardised for age.
DISABILITY AND OBESITY
The prevalence of disability in people aged 60 years and over
increased according to BMI status. Compared to those with
a normal BMI, the prevalence of disability in those who were
obese was more than twice as high (Figure 3.12).
Figure 3.12: Prevalence of disability in 2011-12 according
to BMI status in 2011-12 among people aged 60 years
and over: the AusDiab Study
0
10
20
30
40
50
Prevalence (%)
21.5
45.9
28.1
Normal Overweight Obese
Data have not been standardised for age.
THE USE OF HEALTHCARE SERVICES
The number of visits to a general practitioner (GP) in the
previous 3 months was higher in those who were obese
compared to those with a normal BMI and those who were
overweight. Among those who were obese, approximately
22% had visited a GP 3 times or more in the previous 3
months compared to around 16% of those with a normal
BMI and those who were overweight (Figure 3.13).
24 AUSDIAB 2012
OBESITY
OBESITY
3:
Figure 3.13: Number of visits to a general practitioner
in the previous 3 months according to obesity status
in 2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
17.4
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
Normal Overweight Obese
100
3
visits
2
visits
1
visit
None
Normal 15.5 17. 6 34.7 32.2
Overweight
16.2 19.0 36.5 28.4
Obese 21.7 19.9 34.4 23.9
3 visits
2 visits
1 visit
None
Data have not been standardised for age.
The number of nights spent in a public or private hospital in the
previous 12 months did not differ by obesity status. Across all
BMI groups, around 90% of people had not spent a night in
hospital in the past 12 months, and approximately 6–7% had
spent 2 nights or more in hospital (Figure 3.14).
Figure 3.14: Number of nights spent in a hospital in
the previous 12 months according to obesity status
in 2011-12: the AusDiab study
3.8
6
83
5.1
12
7
90.2 89.9
3.1
0
20
40
60
80
Percentage (%)
Normal Overweight Obese
100
2
nights
1
night
None
Normal 6.0 3.9 9 0 .1
Overweight
7. 5 3.7 88.8
Obese 6.8 3.8 89.4
2 nights
1 night
None
Data have not been standardised for age.
REFERENCES
1
Hartz AJ, Rupley DC, Jr., Kalkhoff RD, Rimm AA. Relationship
of obesity to diabetes: influence of obesity level and body fat
distribution. Prev Med. Mar 1983;12(2):351-357.
2
Alberti KG. The clinical implications of impaired glucose
tolerance. Diabet Med. Nov 1996;13(11):927-937.
3
World Health Organization. Obesity - Preventing and
Managing the Global Epidemic: Report of a WHO Expert
Committee. Geneva: World Health Organization 1998.
4
Alberti KG, Eckel RH, Grundy SM, et al. Harmonizing
the metabolic syndrome: a joint interim statement of
the International Diabetes Federation Task Force on
Epidemiology and Prevention; National Heart, Lung,
and Blood Institute; American Heart Association; World
Heart Federation; International Atherosclerosis Society;
and International Association for the Study of Obesity.
Circulation. Oct 20 2009;120(16):1640-1645.
25
AUSDIAB 2012
OBESITY
OBESITY
3:
BLOOD
PRESSURE
4:
AUSDIAB 2012
BLOOD PRESSURE 25
26 AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
HYPERTENSION
Hypertension was defined as having a blood pressure 140/90
mmHg and/or taking blood pressure-lowering medication in
accordance with the World Health Organization guidelines 3.
Classification of blood pressure is outlined in Table 4.1.
Table 4.1: Classification of blood pressure
INCIDENT HYPERTENSION
New (incident) cases of hypertension were defined as:
(i) people who were classified with normal blood pressure
at baseline, but had developed hypertension at follow-up in
2011-12; or (ii) people who were classified with normal blood
pressure at baseline, but had developed hypertension at
follow-up in 2004-05 and did not attend follow-up in 2011-12.
High blood pressure (hypertension) represents an important risk factor for cardiovascular and
kidney disease in the general population. In people with diabetes, it is a risk factor for microvascular
complications as well as for cardiovascular disease. Thus, high blood pressure is of major
significance to the whole population 1, 2.
In the baseline AusDiab survey conducted in 1999-2000, one in three Australians aged 25 years
and over were classified as being hypertensive (either as having a blood pressure 140/90 mmHg
or taking blood pressure-lowering medication). The 5-year and 12-year follow-up surveys provided
an opportunity to measure the development of hypertension among Australians.
At follow-up in 2011-12, a random sample of people were asked to participate in an additional
sub-study for ambulatory blood pressure monitoring (ABPM). The ABPM device monitors blood
pressure over a period of 24 hours while the person goes about their normal daily activities,
including sleep and rest. This allows independent assessment of daytime and nighttime blood
pressure, in addition to overall 24-hour blood pressure.
This chapter presents: (i) the incidence (% per year) of hypertension, (ii) the impact of various
risk
factors on the development of hypertension, (iii) trends in the percentage of the population
with
hypertension and the use of antihypertensives, (iv) the relationship of depression, cognitive
impairment, and disability with hypertension, (v) blood pressure measured in the ABPM sub-study,
and (vi) healthcare utilisation in hypertension.
4:
BLOOD PRESSURE
DEFINITIONS
Normal <14 0 and <90 and No
Hypertension 140 or 90 or Yes
Systolic
blood
pressure
(mmHg)
Diastolic
blood
pressure
(mmHg)
Blood
pressure-
lowering
medication
27
AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
INCIDENCE OF HYPERTENSION
The incidence of hypertension was 2.9% per year (3.3%
per year in men and 2.6% per year in women) (Figure 4.1).
There was a mean 3.3 mmHg increase in systolic blood
pressure between baseline and 2011-12.
For those classified with normal blood pressure (<140/90
mmHg and not taking blood pressure medication) at baseline,
27.9% had developed hypertension at follow-up in 2011-12
.
For those classified with hypertension at baseline, 13.7%
were classified as having normal blood pressure at follow-up
in 2011-12 (Table 4.2).
Table 4.2: Proportions of individuals classified with
hypertension in 2011-12 according to baseline
hypertension status: the AusDiab study
HYPERTENSION
STATUS AT
BASELINE
HYPERTENSION STATUS
IN 2011-12
nNormal blood
pressure
Hypertension
Normal blood
pressure 3,447 2,486 (72.1) 9 6 1 ( 2 7. 9 )
Hypertension 1,13 9 156 (13.7) 983 (86.3)
Tot a l 4,586 2,642 1, 9 44
Data are n (%). Hyper tension is defined as having a blood pressure
140 /90 mmHg and/or taking blood pressure-lowering medication.
The incidence of hypertension increased according to age,
ranging from 1.0% per year for people aged 25-34 years at
baseline to 7.5% per year for people aged over 75 years at
baseline (Figure 4.1).
In each age group, men had a higher incidence of hypertension
compared to women, and these differences were particularly
evident for those aged 25-54 years at baseline. There was little
difference between men and women for the annual incidence
of hypertension in those aged 55 years and older at baseline
(Figure 4.1).
Figure 4.1: Annual incidence of hypertension according to
baseline age: the AusDiab study
4
2
0
8
Incidence (% per year)
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
Men Women All
25-34 1. 3 0.9 1.0
35-44 2.3 1. 5 1.8
45-54 3.6 2.9 3.2
55-64 4.8 4.6 4.7
65 - 74 7. 5 7.1 7. 3
75+ 7. 6 7. 5 7. 5
All 3.3 2.6 2.9
6
Compared to people with normal glucose tolerance (NGT) at
baseline, the annual incidence of hypertension was greater for
people with impaired fasting glucose (IFG), impaired glucose
tolerance (IGT) and diabetes; with the annual incidence of
hypertension being 2.5 times greater among people with
diabetes at baseline than among people with NGT at baseline
(Figure 4.2).
Among those with NGT, IFG or IGT at baseline, the incidence
of hypertension was higher in men than in women. However,
among those with diabetes at baseline, the incidence of
hypertension was higher in women than in men (Figure 4.2).
The impact of diabetes on the incidence of hypertension
was greater for women than for men. For women, the annual
incidence of hypertension was nearly 3 times higher among
those with diabetes compared to those with NGT at baseline.
However, for men, the annual incidence of hypertension among
those with diabetes at baseline was approximately twice as high
as the incidence of those who had NGT at baseline (Figure 4.2).
RESULTS
28 AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
Figure 4.2: Annual incidence of hypertension according
to baseline glucose tolerance status: the AusDiab study
Men Women All
0
2
4
6
8
Incidence (% per year)
NGT DMIFG IGT
Baseline glucose tolerance status
2.9
2.4 2.6
4.4
3.9 4.3
5.4
4.4 4.8
6.1
7.0
6.5
NGT – normal glucose tolerance; IFG – impaired fasting glucose;
IGT – impaired glucose tolerance; DM – diabetes mellitus.
The heights of bars on all graphs are accurate to two decimal places,
but data labels are rounded to one decimal place.
The incidence of hypertension was higher in people who were
overweight or obese at baseline, compared to those who had
a normal body mass index (BMI) at baseline (Figure 4.3).
Among those with a normal BMI at baseline, the incidence of
hypertension in men was 50% higher than in women. Among
those who were overweight and obese, there was only a small
difference in incidence of hypertension between men and
women (Figure 4.3).
The impact of obesity on the incidence of hypertension was
greater for women than for men. For women, the annual
incidence of hypertension was almost 3 times greater among
those who were obese at baseline compared to those who
had a normal BMI at baseline. However for men, the annual
incidence of hypertension among those who were obese at
baseline was only a little under twice the incidence of those
who had a normal BMI at baseline (Figure 4.3).
Figure 4.3: Annual incidence of hypertension according
to baseline body mass index status: the AusDiab study
0
2
4
6
Incidence (% per year)
2.6
3.3
4.9
1.7
3.3
4.8
2.0
3.3
4.8
Baseline BMI status
Men Women All
Normal Overweight Obese
BMI – body mass index; where (i) normal was a BMI of <25 kg/m
2
,
(ii) overweight was a BMI of 25-29.9 kg/m
2
and (iii) obese was a BMI
of 30 kg/m2.
In general, the incidence of hypertension was higher in
smokers than in non-smokers. Among men, the incidence of
hypertension in smokers was 30% higher than in non-smokers
(Figure 4.4).
Figure 4.4: Annual incidence of hypertension according
to baseline smoking status: the AusDiab study
Men Women All
0
1
2
3
4
Incidence (% per year)
2.9
3.8
2.6 2.5
2.7
3.1
Non-smokers Smokers
Baseline smoking status
29
AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
PERCENTAGE OF THE POPULATION
WITH HYPERTENSION
The percentage of the population with hypertension at the
three time points is shown in Figure 4.5. As the population
aged over the 12 years, this percentage rose from 32.7% to
42.3%. At each time point, the percentage with hypertension
was higher in men than in women.
Figure 4.5: Trends in the percentage of the population
with hypertension in 1999-2000, 2004-05 and 2011-12
according to sex: the AusDiab study
0
10
20
40
50
Percentage (%)
36.6
29.4
32.7
37.6
32.8 35.0
46.7
38.8
42.3
Men
Women
All
30
1999-2000 2004-05 2011-12
Data have not been standardised for age.
USE OF ANTIHYPERTENSIVE
MEDICATION
The percentage of the population who were on
antihypertensive medication and the percentage who were
meeting the blood pressure target of <140/90 mmHg at the
three time points is shown in Figure 4.6. As the population
aged over the 12 years, the percentage who were on
antihypertensive medication rose from 15.8% to 20.6%,
and the percentage who were meeting the blood pressure
target remained constant at approximately 71%.
Figure 4.6: Use of antihypertensive medication and the
percentage of people meeting blood pressure target of
<140/90 mmHg in 1999-2000, 2004-05 and 2011-12:
the AusDiab study
0
20
40
60
80
Percentage (%)
15.8
70.9
23.2
70.1
20.6
71.1
On antihypertensives
BP <140/90
1999-2000 2004-05 2011-12
Data have not been standardised for age.
DEPRESSION AND HYPERTENSION
The prevalence of depression was approximately 8% higher
in people with hypertension compared to people with normal
blood pressure (Figure 4.7).
Figure 4.7: Prevalence of depression in 2011-12 according
to hypertension status in 2011-12: the AusDiab study
0
4
8
12
Prevalence (%)
10.4 11.2
Normal Hypertension
Data have not been standardised for age.
30 AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
COGNITIVE IMPAIRMENT AND
HYPERTENSION
Among people aged 60 years and over, the prevalence
of cognitive impairment was 74% higher in people with
hypertension compared to people with normal blood
pressure (Figure 4.8).
Figure 4.8: Prevalence of cognitive impairment in 2011-12
according to hypertension status in 2011-12 among people
aged 60 and over: the AusDiab Study
0
2
4
6
Prevalence (%)
3.1
5.4
Normal Hypertension
Data have not been standardised for age.
DISABILITY AND HYPERTENSION
Among people aged 60 years and over, the prevalence
of disability was approximately 22% higher in those with
hypertension compared to those with normal blood pressure
(Figure 4.9)
.
Figure 4.9: Prevalence of disability in 2011-12 according
to hypertension status in 2011-12 among people aged
60 years and over: the AusDiab Study
0
10
20
30
40
Prevalence (%)
27.5
33.7
Normal Hypertension
Data have not been standardised for age.
AMBULATORY BLOOD PRESSURE
MONITORING
Figures 4.10 and 4.11 show the results of ambulatory blood
pressure monitoring (ABPM), and illustrate how blood pressure
varies across a 24-hour period. In men and women, both
systolic and diastolic blood pressure were lower during the
night than during the day. Among men, mean night time systolic
blood pressure was 12.2 mmHg lower than during the day, and
among women, the mean fall overnight was 11.1 mmHg.
Overall, systolic and diastolic blood pressures measured by
ABPM were higher in men than in women.
In men, the mean systolic blood pressure measured on-site was
higher than mean daytime values measured by ABPM, while
in women, the mean systolic blood pressure measured on-site
was similar to the mean daytime values measured by ABPM.
In both men and women, the mean diastolic blood pressure
measured on-site were lower than the mean daytime values
measured by ABPM.
Figure 4.10: Mean blood pressure measured by
ambulatory blood pressure monitoring over a 24-hour
period in 2011-12 in men: the AusDiab study
0
40
80
120
160
Systolic BP Diastolic BP
Midday 6:00 PM Midnight 6:00 AM Midday
Blood pressure (mmHg)
31
AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
Figure 4.11: Mean blood pressure measured by
ambulatory blood pressure monitoring over a 24-hour
period in 2011-12 in women: the AusDiab study
Blood pressure (mmHg)
160
0
40
80
120
Systolic BP Diastolic BP
Midday 6:00 PM Midnight 6:00 AM Midday
USE OF HEALTHCARE SERVICES
The number of visits to a general practitioner (GP) in the
previous 3 months was higher in those with hypertension
compared to those with normal blood pressure. Among those
with hypertension, around 23% had visited a GP 3 times or
more in the previous 3 months, compared to 14% of people
with normal blood pressure (Figure 4.12).
Figure 4.12: Number of visits to a general practitioner in
the previous 3 months according to hypertension status
in 2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
Normal Hypertension
100
3
visits
2
visits
1
visit
None
Normal 13.7 1 7. 3 34.3 34.8
Hypertension
22.8 21.1 36.6 19.5
3 visits
2 visits
1 visit
None
Data have not been standardised for age.
Of those with hypertension, almost 9% spent 2 nights or more
in hospital in the previous 12 months compared to 5% of those
with normal blood pressure (Figure 4.13).
Figure 4.13: Number of nights spent in a hospital in the
previous 12 months according to hypertension status in
2011-12: the AusDiab study
83
5.15.1
1212
90.2
0
20
40
60
80
Percentage (%)
Normal Hypertension
100
2
nights
1
night
None
Normal 5.4 3.6 90.9
Hypertension
8.8 4.0 8 7. 2
2 nights
1 night
None
Data have not been standardised for age
.
REFERENCES
1
Tight blood pressure control and risk of macrovascular
and microvascular complications in type 2 diabetes:
UKPDS 38. UK Prospective Diabetes Study Group.
BMJ. Sep 12 1998;317(7160):703-713.
2
Efficacy of atenolol and captopril in reducing risk of
macrovascular and microvascular complications in
type 2 diabetes: UKPDS 39. UK Prospective Diabetes
Study Group. BMJ. Sep 12 1998;317(7160):713-720.
3
1999 World Health Organization-International Society
of Hypertension Guidelines for the Management of
Hypertension. Guidelines Subcommittee. J Hypertens.
Feb 1999;17(2):151-183.
032 AUSDIAB 2012
TABLE OF CONTENTS
32 AUSDIAB 2012
33
AUSDIAB 2012
BLOOD PRESSURE
BLOOD PRESSURE
4:
METABOLIC
SYNDROME
5:
AUSDIAB 2012
METABOLIC SYNDROME 33
34 AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
METABOLIC SYNDROME
The metabolic syndrome was defined according to the Joint
Interim Statement on the metabolic syndrome
1
. Classification
of the metabolic syndrome is outlined in Table 5.1
.
Table 5.1: Classification of the metabolic syndrome
COMPONENT THRESHOLD
Waist circumference Europids:
94 cm for men,
80 cm for women
South and South-East
Asians:
90 cm for men,
80 cm for women
Plus two or more of the following:
Raised triglycerides
1.7 mmol/l or specific
treatment of this lipid
abnormality
Reduced HDL-cholesterol
<1.0 mmol/l in men;
<1.3 mmol/l in women
or specific treatment of
this lipid abnormality
Raised blood pressure
Systolic 130 mmHg or
diastolic 85 mmHg or
treatment of previously
diagnosed hypertension
Raised plasma glucose
Fasting plasma glucose
5.6 mmol/l or previously
diagnosed type 2 diabetes
INCIDENT METABOLIC SYNDROME
New (incident) cases of the metabolic syndrome were
defined as people who did not meet the criteria for the
metabolic syndrome at baseline, but satisfied the criteria
at follow-up in 2004-05 and 2011-12.
There were 160 people who did not meet the criteria for
the metabolic syndrome at baseline and satisfied the criteria
at follow-up in 2004-05, but did not satisfy the criteria at
follow-up in 2011-12. These people were not included as
incident metabolic syndrome cases.
The metabolic syndrome is characterized by central or abdominal (visceral and
retroperitoneal) obesity and clustering of other cardiovascular risk factors including abnormal
glucose tolerance (diabetes, impaired glucose tolerance (IGT) or impaired fasting glucose
(IFG)), raised triglycerides, decreased high-density lipoprotein cholesterol (HDL-C), elevated
blood pressure, and hyperinsulinaemia with underlying insulin resistance. The clustering of
these risk factors together confers a higher risk of diabetes and cardiovascular disease.
This chapter presents: (i) the incidence (% per year) and the percentage of the population
with the metabolic syndrome, (ii) the impact of various risk factors on the development
of the metabolic syndrome, (iii) the relationship of depression, cognitive impairment, and
disability with the metabolic syndrome, and (iv) healthcare utilisation in the metabolic syndrome.
5:
METABOLIC SYNDROME
DEFINITION
35
AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
INCIDENCE OF THE METABOLIC
SYNDROME
The prevalence of the metabolic syndrome at baseline was
31.0%. The annual incidence of the metabolic syndrome
in those who did not meet the criteria for the metabolic
syndrome at baseline was 50% higher in men than in women
(Figure 5.1).
In men, the annual incidence of the metabolic syndrome
increased between the ages of 25 and 54 years, decreasing
slightly between the ages of 55 and 64 years, then peaking
between the ages of 65 and 74 years, before declining after
the age of 75 years. In women, the incidence of the metabolic
syndrome was less variable and increased with age until
plateaueing after the age of 65 years (Figure 5.1).
The incidence of the metabolic syndrome between the ages of
25 and 64 was higher in men than in women. However, after the
age of 65 years, the incidence of the metabolic syndrome was
higher in women than in men (Figure 5.1).
Figure 5.1: Annual incidence of the metabolic syndrome
according to baseline age: the AusDiab study
2
1
0
3
4
Incidence (% per year)
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
Men Women All
25-34 1. 8 1.0 1. 3
35-44 2.3 1. 2 1.6
45-54 2.9 1. 8 2.3
55-64 2.7 2.2 2.4
65 - 74 3.5 3.7 3.6
75+ 3 .1 3.7 3.4
All 2.6 1.7 2 .1
The annual incidence of the metabolic syndrome increased as
waist circumference at baseline increased. Compared to those
with a low risk waist circumference at baseline, those with a
high risk waist circumference were approximately twice as likely
to develop the metabolic syndrome (Figure 5.2).
Within both of the waist circumference risk categories, men
had a greater annual incidence of the metabolic syndrome
than did women (Figure 5.2).
Figure 5.2: Annual incidence of the metabolic
syndrome according to baseline waist circumference:
the AusDiab study
Men Women All
0
1
2
3
4
Incidence (% per year)
2.0
3.6
1.0
2.7
1.4
3.0
Low risk High risk
Baseline waist circumference
Waist circumference : (i) low risk: <94 cm for Europid men, <90 cm
for Aboriginal/Torres Strait Islander, Asian and South European men,
<80 cm for women; (ii) high risk: 94 cm for Europid men, 90 cm
for Aboriginal/Torres Strait Islander, Asian and South European men,
80 cm for women.
The heights of bars on all graphs are accurate to two decimal places,
but data labels are rounded to one decimal place.
When the incidence of the metabolic syndrome was examined
according to baseline body mass index (BMI), the incidence
in those who were categorized as normal (BMI<25 kg/m
2
),
overweight (BMI 25-29.9 kg/m2) and obese (BMI 30 kg/m2)
at baseline was 1.3%, 2.8% and 3.9% per year respectively.
The incidence of the metabolic syndrome was slightly higher
among those who reported insufficient physical activity at
baseline compared to those who reported sufficient physical
activity at baseline (Figure 5.3).
RESULTS
36 AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
Figure 5.3: Annual incidence of the metabolic syndrome
according to baseline physical activity: the AusDiab study
Men Women All
0
1
2
3
Incidence (% per year)
2.9
2.5
1.9
1.6
2.2
2.0
Insufficient Sufficient
Baseline physical activity category
‘Physical activity time’ for the previous week was calculated as the sum
of the time spent performing moderate activity (e.g. walking) plus
double the time spent in vigorous activity (to reflect its greater intensity).
Insufficient: 1-149 minutes of physical activity in the previous week;
sufficient: 150 minutes of physical activity in the previous week.
The annual incidence of the metabolic syndrome was greater in
those with diabetes at baseline compared to those with normal
glucose tolerance at baseline. In men, the incidence of the
metabolic syndrome in those with pre-diabetes was between
the incidence in those with normal glucose tolerance and those
with diabetes at baseline. However, in women, the incidence of
the metabolic syndrome was highest in those with impaired
glucose tolerance at baseline (Figure 5.4).
Figure 5.4: Annual incidence of the metabolic syndrome
according to baseline glucose tolerance status: the
AusDiab study
Men Women All
0
2
4
6
8
Incidence (% per year)
NGT DMIFG IGT
Baseline glucose tolerance status
2.3
1.6 1.9
4.3
3.0
3.4
5.0
6.4
5.3
6.4
5.5
6.0
NGT: normal glucose tolerance; IFG: impaired fasting glucose;
IGT: impaired glucose tolerance; DM: diabetes mellitus.
PERCENTAGE OF THE POPULATION
WITH THE METABOLIC SYNDROME
The percentage of the population with the metabolic
syndrome at the three time points is shown in Figure 5.5.
As the population aged over the 12 years, this percentage
decreased from 35.1% to 33.5%. At each time point, the
percentage with the metabolic syndrome was higher in
men than women.
Figure 5.5: Trends in the percentage of the population
with the metabolic syndrome in 1999-2000, 2004-05 and
2011-12 according to sex: the AusDiab study
0
10
20
40
50
Percentage (%)
41.0
30.3
35.1
37.4
28.5
32.5
39.6
28.6
33.5
Men
Women
All
30
1999-2000 2004-05 2011-12
Data have not been standardised for age.
37
AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
DEPRESSION AND THE METABOLIC
SYNDROME
The prevalence of depression was 31% higher in those who met
the criteria for the metabolic syndrome at follow-up in 2011-12
compared to those who did not meet the criteria (Figure 5.6).
Figure 5.6: Prevalence of depression in 2011-12
according to metabolic syndrome status in 2011-12:
the AusDiab study
0
4
8
12
16
Prevalence (%)
9.7
12.7
Normal Metabolic syndrome
Data have not been standardised for age.
COGNITIVE IMPAIRMENT AND THE
METABOLIC SYNDROME
Among people aged 60 years and over, the prevalence of
cognitive impairment was almost double in those who met
the criteria for the metabolic syndrome at follow-up in 2011-12
compared to those who did not meet the criteria (Figure 5.7).
Figure 5.7: Prevalence of cognitive impairment in 2011-12
according to metabolic syndrome status in 2011-12 among
people aged 60 and over: the AusDiab Study
0
2
4
6
8
Prevalence (%)
3.2
6.2
Normal Metabolic syndrome
Data have not been standardised for age.
DISABILITY AND THE METABOLIC
SYNDROME
Among those aged 60 years and over, the prevalence of
disability was almost 50% higher in those who met the criteria
for the metabolic syndrome at follow-up in 2011-12 compared
to those who did not meet the criteria ( Figure 5.8).
Figure 5.8: Prevalence of disability in 2011-12 according
to metabolic syndrome status in 2011-12 among people
aged 60 years and over: the AusDiab Study
0
10
20
30
40
Prevalence (%)
26.0
38.4
Normal Metabolic syndrome
Data have not been standardised for age.
USE OF HEALTHCARE SERVICES
The number of visits to a general practitioner (GP) in the
previous 3 months was higher in those who met the criteria
for the metabolic syndrome at follow-up in 2011-12 compared
to those who did not meet the criteria.
Among those who met the criteria for the metabolic
syndrome, approximately 23% of people had visited a GP 3
times or more, compared to only 15% of people who did not
meet the criteria for the metabolic syndrome ( Figure 5.9).
38 AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
Figure 5.9: Number of visits to a general practitioner in
the previous 3 months according to metabolic syndrome
status in 2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
Normal Metabolic syndrome
100
3
visits
2
visits
1
visit
None
Normal 14.7 18.3 35.4 31.7
Metabolic
syndrome
23 .1 20.2 35.0 21. 8
3 visits
2 visits
1 visit
None
Data have not been standardised for age.
The number of nights spent in a hospital in the past 12 months
was greater in those who met the criteria for the metabolic
syndrome at follow-up in 2011-12 compared to those who did
not meet the criteria.
Among those who met the criteria for the metabolic syndrome,
9% had stayed in a hospital for 2 nights or more, compared
to almost 6% of people who did not meet the criteria for the
metabolic syndrome (Figure 5.10).
Figure 5.10: Number of nights spent in a hospital in the
previous 12 months according to metabolic syndrome
status in 2011-12: the AusDiab study
83
5.15.1
1212
90.2
0
20
40
60
80
Percentage (%)
Normal Metabolic syndrome
100
2
nights
1
night
None
Normal 5.7 3.9 90.4
Metabolic
syndrome
9.0 3.6 87.4
2 nights
1 night
None
Data have not been standardised for age
.
REFERENCES
1
Alberti KG, Eckel RH, Grundy SM, et al. Harmonizing
the metabolic syndrome: a joint interim statement of
the International Diabetes Federation Task Force on
Epidemiology and Prevention; National Heart, Lung,
and Blood Institute; American Heart Association; World
Heart Federation; International Atherosclerosis Society;
and International Association for the Study of Obesity.
Circulation. Oct 20 2009;120(16):1640-1645.
39
AUSDIAB 2012
METABOLIC SYNDROME
METABOLIC SYNDROME
5:
CHRONIC
KIDNEY DISEASE
6:
AUSDIAB 2012
CHRONIC KIDNEY DISEASE 39
40 AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
IMPAIRED ESTIMATED GLOMERULAR
FILTRATION RATE
Chronic kidney disease is defined as present when there
is impaired kidney function. The ideal measure of kidney
function is the glomerular filtration rate (GFR). GFR can be
estimated from the results of a blood test (so called ‘estimated’
GFR or eGFR) and an impaired eGFR is defined as eGFR
<60 ml/min/1.73m 2, 7. In the AusDiab study, the eGFR has
been calculated using the abbreviated MDRD formula 8.
INCIDENT IMPAIRED ESTIMATED
GLOMERULAR FILTRATION RATE
New (incident) cases of impaired eGFR were defined as
individuals who had a normal eGFR (60 ml/min/1.73m
2
) at
baseline, but had an eGFR of <60 ml/min/1.73m 2 at follow-up
in 2004-05 and 2011-12. There were 42 people with normal
eGFR at baseline and impaired eGFR at follow-up in 2004-05,
but normal eGFR at follow-up in 2011-12. These people were
not included as incident cases.
ALBUMINURIA
Kidney disease can manifest as the leakage of protein into
the urine, with or without impairment of kidney function.
The earliest manifestation of an excessive leakage of protein
into the urine can be detected by measuring urinary albumin
excretion and is called albuminuria.
Albuminuria was considered to be present if the spot urine
albumin:creatinine ratio was 2.5 mg/mmol for men and
3.5 mg/mmol for women. Albuminuria is a recognized risk
factor for the progression of chronic kidney disease and
additionally is an important risk factor for cardiovascular
disease and mortality
9-11
.
INCIDENT ALBUMINURIA
Incident cases of albuminuria were defined as people who
had normal albumin:creatinine levels in the urine at baseline,
but had abnormal albumin:creatinine levels in urine
(2.5 mg/mmol for men and 3.5 mg/mmol for women) at
follow-up in 2004-05 and 2011-12. There were 59 people who
had normal albumin:creatinine levels in urine at baseline and
abnormal albumin:creatinine levels at follow-up in 2004-05,
but normal albumin:creatinine levels at follow-up in 2011-12.
These people were not included as incident cases.
Chronic kidney disease is common in the general community and is associated with significant
physical and mental disability
1, 2
. Individuals with chronic kidney disease are at increased risk
of progressing to complete kidney failure (so called “end-stage kidney failure”) requiring dialysis
or transplantation. They are also predisposed to the development of premature cardiovascular
disease with an increased risk of mortality due to heart attack or stroke
3, 4
.
The number of new (incident) cases of treated end-stage kidney disease in Australia is
approximately 101 per million population per year, with diabetes being the leading cause
5
.
Currently 35% of all new end-stage kidney disease is due to diabetes
5
, compared with 17%
in 1994
6
. The other common causes of end-stage kidney disease include glomerulonephritis
(23%) and vascular kidney disease related to hypertension and/or atherosclerosis (15%)
5
.
This chapter presents: (i) the incidence (% per year) and the percentage of the population with
impaired estimated glomerular filtration rate (eGFR) and with albuminuria, (ii) the impact of
various risk factors on the development of impaired eGFR and albuminuria, (iii) the relationship
of depression, cognitive impairment, and disability with impaired eGFR and albuminuria, and
(iv) healthcare utilization in impaired eGFR and albuminuria.
6:
CHRONIC KIDNEY DISEASE
DEFINITIONS
41
AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
INCIDENCE OF IMPAIRED ESTIMATED
GLOMERULAR FILTRATION RATE
The incidence of impaired eGFR was 0.4% per year as
presented in Figure 6.1. The annual incidence of impaired
eGFR increased with age, with an incidence close to zero
among those aged between 25 and 54 years at baseline
rising to 3.8% in those aged 75 years and over at baseline.
In general, there was little difference in the incidence of
impaired eGFR between men and women.
Figure 6.1: Annual incidence of impaired estimated
glomerular filtration rate according to baseline age:
the AusDiab study
2
1
0
3
4
Incidence (% per year)
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
Men Women All
25-34 0.0 0 .1 0.0
35-44 0 .1 0 .1 0 .1
45-54 0.2 0.3 0.2
55-64 0.4 0.7 0.6
65 - 74 1.7 1.7 1.7
75+ 3.9 3.6 3.8
All 0.4 0.5 0.4
The annual incidence of impaired eGFR according to
baseline glucose tolerance status is presented in Figure 6.2.
The incidence of impaired eGFR was highest in those with
diabetes and lowest in those with NGT. The incidence of
impaired eGFR in those with IFG was approximately 40%
higher than that seen in those with IGT.
The incidence of impaired eGFR was higher for women
than for men in those with NGT, IFG and diabetes at baseline.
However, the incidence of impaired eGFR was higher in men
than in women in those with IGT (Figure 6.2).
Figure 6.2: Annual incidence of impaired estimated
glomerular filtration rate according to baseline glucose
tolerance status: the AusDiab study
Men Women All
0.0
0.4
0.8
1.2
1.6
Incidence (% per year)
NGT DMIFG IGT
Baseline glucose tolerance status
0.3 0.4 0.3
0.7 0.8 0.7
0.5
0.4 0.5
1.3
1.4 1.4
NGT – normal glucose tolerance; IFG – impaired fasting glucose;
IGT – impaired glucose tolerance; DM – diabetes mellitus.
The heights of bars on all graphs are accurate to two decimal places,
but data labels are rounded to one decimal place.
The annual incidence of impaired eGFR was approximately 5
times higher in those with hypertension compared to those with
normal blood pressure. In those with hypertension, the incidence
of impaired eGFR was higher in women compared to men
(Figure 6.3).
Figure 6.3: Annual incidence of impaired estimated
glomerular filtration rate according to baseline
hypertension status: the AusDiab study
Men Women All
0.0
0.4
0.8
1.2
Incidence (% per year)
0.2
1.0
0.3
1.2
0.2
1.1
Normal Hypertension
Baseline hypertension status
RESULTS
42 AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
PERCENTAGE OF THE POPULATION
WITH IMPAIRED ESTIMATED
GLOMERULAR FILTRATION RATE
The percentage of the population with impaired eGFR at the
three time points is shown in Figure 6.4. As the population
aged over the 12 year study period, this percentage rose from
4.0% to 4.8%. At all time points, the percentage with impaired
eGFR was higher in women than in men.
Figure 6.4: Trends in the percentage of the population with
impaired estimated glomerular filtration rate in 1999-2000,
2004-05 and 2011-12 according to sex: the AusDiab study
0
2
4
6
Percentage (%)
3.6
4.4 4.0
4.9 5.2 5.1
4.3
5.3
4.8
Men
Women
All
1999-2000 2004-05 2011-12
Data have not been standardised for age.
DEPRESSION AND GLOMERULAR
FILTRATION RATE
The prevalence of depression was higher in those with
impaired eGFR compared to those with normal eGFR
(Figure 6.5).
Figure 6.5: Prevalence of depression in 2011-12 according
to estimated glomerular filtration rate status in 2011-12:
the AusDiab study
0
4
8
12
16
Prevalence (%)
10.6
14.5
Normal Impaired eGFR
Data have not been standardised for age.
COGNITIVE IMPAIRMENT AND
GLOMERULAR FILTRATION RATE
In those aged over 60 years, the prevalence of cognitive
impairment was almost 65% higher in those with impaired
eGFR compared to those with normal eGFR (Figure 6.6).
Figure 6.6: Prevalence of cognitive impairment in
2011-12 according to estimated glomerular filtration
rate status in 2011-12 among people aged 60 and over:
the AusDiab Study
0
2
4
6
8
Prevalence (%)
4.2
6.9
Normal Impaired eGFR
Data have not been standardised for age.
DISABILITY AND GLOMERULAR
FILTRATION RATE
The prevalence of disability in those aged over 60 years with
impaired eGFR was 65% higher than in those aged over 60
years with normal eGFR (Figure 6.7).
Figure 6.7: Prevalence of disability in 2011-12 according
to
estimated glomerular filtration rate status in 2011-12
among people aged 60 and over: the AusDiab Study
Prevalence (%)
29.6
48.9
Normal Impaired eGFR
0
20
40
60
Data have not been standardised for age.
43
AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
USE OF HEALTHCARE SERVICES BY
GLOMERULAR FILTRATION RATE STATUS
The number of visits to a general practitioner in the previous 3
months according to eGFR status is presented in Figure 6.8.
In those with normal eGFR, 29.2% had not visited a GP in the
previous 3 months, compared to only 11.0% of those with
impaired eGFR. In contrast, 34.9% of people with impaired
eGFR had visited a GP 3 times or more in the previous 3
months, compared to 16.7% of people with normal eGFR.
Figure 6.8: Number of visits to a general practitioner in
the previous 3 months according to estimated glomerular
filtration rate status in 2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
Normal Impaired eGFR
100
3
visits
2
visits
1
visit
None
Normal 16.7 18 .7 35.4 29.2
Impaired
eGFR
34.9 22.5 3 1.6 11.0
3 visits
2 visits
1 visit
None
Data have not been standardised for age.
The number of nights spent in a hospital in the previous 12
months was higher in those with impaired eGFR. In those with
impaired eGFR, 14.4% had spent at least two nights in hospital
compared to only 6.5% of those with normal eGFR (Figure 6.9).
Figure 6.9: Number of nights spent in a hospital in the
previous 12 months according to estimated glomerular
filtration rate status in 2011-12: the AusDiab study
83
5.15.1
1212
90.2
0
20
40
60
80
Percentage (%)
Normal Impaired eGFR
100
2
nights
1
night
None
Normal 6.5 3.7 89.9
Impaired
eGFR
14.4 5.7 79.9
2 nights
1 night
None
Data have not been standardised for age.
INCIDENCE OF ALBUMINURIA
The incidence of albuminuria was 0.7% per year, with the
incidence in men almost double that in women. In both men
and women, the annual incidence of albuminuria increased
with increasing age beyond 45 years (Figure 6.10).
44 AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
Figure 6.10: Annual incidence of albuminuria according
to baseline age: the AusDiab study
4
2
0
6
Incidence (% per year)
Men
Women
All
Baseline age (years)
25-34 35-44 45-54 55-64 75+65-74 All
Men Women All
25-34 0.3 0.4 0.3
35-44 0.2 0.3 0.3
45-54 0.6 0.3 0.4
55-64 1.1 0.6 0.8
65 - 74 2.7 1.5 2 .1
75+ 5.5 3.3 4.3
All 0.9 0.5 0.7
The annual incidence of albuminuria was highest in those
with diabetes at baseline, and lowest in those with NGT at
baseline. In men, the incidence of albuminuria was lower
in those with IGT compared to those with IFG. However, in
women, the incidence of albuminuria was higher in those with
IGT compared to those with IFG. The incidence of albuminuria
was higher in men than in women in those with NGT, IFG and
diabetes, but lower in those with IGT (Figure 6.11).
Figure 6.11: Annual incidence of albuminuria according to
baseline glucose tolerance status: the AusDiab study
Men Women All
0
1
2
3
4
Incidence (% per year)
NGT DMIFG IGT
Baseline glucose tolerance status
0.6 0.4 0.5
1.5
0.5
0.9 1.0
1.3
1.0
3.3
1.9
2.6
NGT – normal glucose tolerance; IFG – impaired fasting glucose;
IGT – impaired glucose tolerance; DM – diabetes mellitus.
The annual incidence of albuminuria was around 3–4 times
higher in those with hypertension than those with normal
blood pressure (Figure 6.12).
Figure 6.12: Annual incidence of albuminuria according to
baseline hypertension status: the AusDiab study
Men Women All
0.0
0.4
0.8
1.2
1.6
2.0
Percentage (%)
0.6
1.7
0.3
1.2
0.4
1.5
Normal Hypertension
Baseline hypertension status
PERCENTAGE OF THE POPULATION
WITH ALBUMINURIA
The percentage of the AusDiab cohort with albuminuria at the
three time points is shown in Figure 6.13. As the cohort aged
over the 12 years of the AusDiab study, this percentage rose
from 7.5% to 8.8%. At each time point, the percentage with
albuminuria was higher in men than women.
Figure 6.13: Trends in the percentage of the population
with albuminuria in 1999-2000, 2004-05 and 2011-12
according to sex: the AusDiab study
0
4
8
12
Percentage (%)
8.9
6.3
7.5
9.3
5.0
6.9
11.7
6.5
8.8
Men
Women
All
1999-2000 2004-05 2011-12
Data have not been standardised for age.
45
AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
DEPRESSION AND ALBUMINURIA
The prevalence of depression was 34% higher in those
with albuminuria compared to those without albuminuria
(Figure 6.14).
Figure 6.14: Prevalence of depression in 2011-12 according
to albuminuria status in 2011-12: the AusDiab study
0
4
8
12
16
Prevalence (%)
10.4
13.9
Normal Albuminuria
Data have not been standardised for age.
COGNITIVE IMPAIRMENT AND
ALBUMINURIA
In those aged 60 years and over, the prevalence of cognitive
impairment was more than twice as high in those with
albuminuria compared to those without albuminuria (Figure 6.15).
Figure 6.15: Prevalence of cognitive impairment in 2011-12
according to albuminuria status in 2011-12 among people
aged 60 and over: the AusDiab Study
0
2
4
6
8
Prevalence (%)
3.6
9.0
Normal Albuminuria
Data have not been standardised for age.
DISABILITY AND ALBUMINURIA
In those aged 60 years and over, the prevalence of disability
was approximately 44% higher in those with albuminuria
compared to those without albuminuria (Figure 6.16).
Figure 6.16: Prevalence of disability in 2011-12 according to
albuminuria status in 2011-12 among people aged 60 and
over: the AusDiab Study
Prevalence (%)
29.3
42.3
Normal Albuminuria
0
10
20
30
40
Data have not been standardised for age.
USE OF HEALTHCARE SERVICES BY
ALBUMINURIA STATUS
The number of visits to a GP in the previous 3 months
according to albuminuria status is presented in Figure 6.17.
In those without albuminuria, 29.7% had not visited a GP in
the previous 3 months, compared to only 15.4% of those
with albuminuria. However, 28.9% of people with albuminuria
had seen a GP 3 times or more in the previous 3 months,
compared to only 16.3% of people without albuminuria.
46 AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
Figure 6.17: Number of visits to a general practitioner in
the previous 3 months according to albuminuria status in
2011-12: the AusDiab study
9.86
35.55
68.8
31.2
25.6
37.8
20.2
31.5
17.8
35.0
15.7
0
20
40
60
80
Percentage (%)
Normal Albuminuria
100
3
visits
2
visits
1
visit
None
Normal 16.3 18.6 35.4 29.7
Albuminuria
28.9 22.0 33.8 15 .4
3 visits
2 visits
1 visit
None
Data have not been standardised for age.
In those with albuminuria, 14.0% had spent at least 2 nights
in hospital in the previous 12 months, compared to 6.0% of
those without albuminuria (Figure 6.18).
Figure 6.18: Number of nights spent in a hospital in the
previous 12 months according to albuminuria status in
2011-12: the AusDiab study
83
5.15.1
1212
90.2
0
20
40
60
80
Percentage (%)
Normal Albuminuria
100
2
nights
1
night
None
Normal 6.0 3.6 90.4
Albuminuria
14.0 5.4 80.6
2 nights
1 night
None
Data have not been standardised for age.
REFERENCES
1
Chadban SJ, Briganti EM, Kerr PG, et al. Prevalence
of kidney damage in Australian adults: The AusDiab kidney
study. J Am Soc Nephrol. Jul 2003;14(7 Suppl 2):S131-138.
2
Chow FY, Briganti EM, Kerr PG, Chadban SJ, Zimmet PZ,
Atkins RC. Health-related quality of life in Australian
adults with renal insufficiency: a population-based study.
Am J Kidney Dis. Mar 2003;41(3):596-604.
3 Anavekar NS, McMurray JJ, Velazquez EJ, et al.
Relation between renal dysfunction and cardiovascular
outcomes after myocardial infarction. N Engl J Med.
Sep 23 2004;351(13):1285-1295.
4 Go AS, Chertow GM, Fan D, McCulloch CE, Hsu
CY. Chronic kidney disease and the risks of death,
cardiovascular events, and hospitalization. N Engl J Med.
Sep 23 2004;351(13):1296-1305.
5 Grace B, Excell L, Dent H, McDonald S. New patients
commencing treatment in 2011, in The 35th report of
the Australia and New Zealand Dialysis and Transplant
Registry 2012. Adelaide: Australia and New Zealand
Dialysis and Transplant Registry 2011.
6
Disney A. Primary renal disease, in The 18th report of the
Australia and New Zealand Dialysis and Transplant Registry
1995. Adelaide: Australia and New Zealand Dialysis and
Transplant Registry;1996.
7 Mathew TH. Chronic kidney disease and automatic
reporting of estimated glomerular filtration rate: a position
statement. Med J Aust. Aug 1 2005;183(3):138-141.
8 Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N,
Roth D. A more accurate method to estimate glomerular
filtration rate from serum creatinine: a new prediction
equation. Modification of Diet in Renal Disease Study
Group. Ann Intern Med. Mar 16 1999;130(6):461-470.
9 Mogensen CE. Microalbuminuria predicts clinical
proteinuria and early mortality in maturity-onset diabetes.
N Engl J Med. Feb 9 1984;310(6):356-360.
10 Hillege HL, Fidler V, Diercks GF, et al. Urinary albumin
excretion predicts cardiovascular and noncardiovascular
mortality in general population. Circulation. Oct 1
2002;106(14):1777-1782.
11 Klausen K, Borch-Johnsen K, Feldt-Rasmussen B, et
al. Very low levels of microalbuminuria are associated
with increased risk of coronary heart disease and death
independently of renal function, hypertension, and
diabetes. Circulation. Jul 6 2004;110(1):32-35.
47
AUSDIAB 2012
CHRONIC KIDNEY DISEASE
CHRONIC KIDNEY DISEASE
6:
PHYSICAL ACTIVITY AND
SEDENTARY BEHAVIOUR
7:
AUSDIAB 2012
PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR 47
48 AUSDIAB 2012
PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR
PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR
7:
DEFINITIONS
Based on self-report information, participants were classified
into one of three categories of physical activity: ‘sufficiently
active’ – at least 150 minutes of moderate-intensity or 75
minutes of vigorous-intensity physical activity in the previous
week; ‘insufficiently active’ – some activity reported in the
previous week, but not meeting the volume specified by the
definition of ‘sufficient’ activity; and, ‘inactive’ – no participation
in physical activity in the previous week.
Participants were asked to estimate the total time spent
watching television or videos on weekdays and weekend days
during the previous week. Total sitting time was determined by
asking participants to report how much time they spent sitting
down while doing things like ‘visiting friends, driving, reading,
watching TV, or working at a desk or a computer.’
Objective activity monitoring, using accelerometers and
inclinometers, provides detailed information on how most
adults spend their day. An Actigraph® GT3X+ accelerometer
and an activPAL3® inclinometer were provided to selected
participants. These devices were worn for seven consecutive
days. All accelerometer and inclinometer data were adjusted
for wear time, to address the daily wear time variation
between participants.
RESULTS
SELF-REPORTED PHYSICAL ACTIVITY
Sixty-four percent of the study sample was classed as
‘sufficiently active’, based on self-reported estimates of
weekly physical activity. Participation at this level was more
common among men than women, but there was no gender
difference in the percentage of participants who reported no
physical activity at all (Figure 7.1).
The health benefits of regular participation in moderate- to vigorous-intensity physical activity are well
established. Physical activity reduces the risk of all-cause mortality, cardiovascular disease, type 2 diabetes,
some cancers, osteoporosis and depression
1
. The National Physical Activity Guidelines for Adults
recommend the ‘accumulation of 30 minutes of moderate-intensity physical activity on most days of the
week’ as the minimum required to obtain health benefits
2
.
Sedentary behaviours involve low energy expenditure ( 1.5 metabolic equivalents [METs], or multiples
of the basal metabolic rate), characterized by prolonged sitting or reclining and the absence of
whole-body movement
3
. Within the general adult population, sedentary behaviour (put simply, ‘sitting
time’) is associated with an elevated risk for all-cause and cardiovascular mortality, cardiovascular
disease, type 2 diabetes and some cancers 4.
Regular participation in physical activity and high levels of sedentary behaviour can coexist: even if adults
meet the public health guidelines for moderate- to vigorous-intensity physical activity, there are deleterious
metabolic consequences of the ten or more hours of sitting that can be accumulated each day. High volumes
of sedentary behaviour and lack of physical activity participation thus can contribute independently and
distinctly to adverse health outcomes 4.
This chapter presents: (i) self-reported average time per day spent doing physical activity and sedentary behaviour,
and (ii) objectively-assessed average time per day spent doing physical activity and sedentary behaviour.
7:
PHYSICAL ACTIVITY AND
SEDENTARY BEHAVIOUR
49
AUSDIAB 2012
PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR
PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOUR
7:
Figure 7.1: Percent of participants classed as sufficiently
active, insufficiently active or inactive in 2011-12: the
AusDiab study
0
20
40
60
80
Percentage (%)
67.0
22.0
11.0
61.0
27.2
11.8
63.7
24.9
11.5
Physical Activity Status
Men Women All
Sufficient Insufficient Inactive
‘Physical activity time’ for the previous week was calculated as the
sum of the time spent performing moderate activity (e.g. walking)
plus double the time spent in vigorous activity (to reflect its greater
intensity). Sufficient: 150 minutes of physical activity in the previous
week; insufficient: <150 minutes of physical activity in the previous
week; inactive: no physical activity in the previous week.
On average, participants reported 50 minutes of moderate- to
vigorous-intensity physical activity per day (56 minutes per
day for men; 45 minutes per day for women). Moderate- to
vigorous-intensity physical activity was somewhat higher
amongst men than women (Figure 7.2).
Figure 7.2: Average time spent doing moderate- to
vigorous-intensity physical activity per day according
to age in 2011-12: the AusDiab study
0
20
40
60
80
Age (years)
Time (mins/day)
Men Women All
35-44 49 45 47
45-54 59 48 52
55-64 56 49 52
65 - 74 60 44 52
75+ 49 32 40
Men
Women
All
35-44 45-54 55-64 65-74 75+
In both men and women, there was a progressive reduction in
self-reported time undertaking moderate- to vigorous-intensity
physical activity across the normal, overweight and obese
categories (Figure 7.3).
Figure 7.3: Average time spent doing moderate- to
vigorous-intensity physical activity per day according
to BMI in 2011-12: the AusDiab study
0
20
40
60
80
Time (mins/day)
65
56
50
55
45
33
59
50
40
BMI status
Men Women All
Normal Overweight Obese
BMI: (i) normal: <25 kg/m
2
; (ii) overweight: 25-29.9 kg/m
2
;
and (iii) obese: 30 kg/m
2
.
Physical activity levels were considerably lower amongst
participants with the metabolic syndrome, compared to
participants who did not meet the criteria for metabolic
syndrome (Figure 7.4).
Figure 7.4: Average time spent doing moderate- to
vigorous-intensity physical activity per day according to
metabolic syndrome status in 2011-12: the AusDiab study
Men Women All
0
20