[Show abstract][Hide abstract] ABSTRACT: Measurement of physical activity in epidemiological studies requires tools which are reliable, valid and culturally relevant. We attempted to develop a physical activity questionnaire (PAQ) that would measure physical activity in various domains over a year and which would be valid for use in adults of different age groups with varying levels of activity in urban and rural settings in low and middle income countries like India. The present paper aims to assess the reliability and validity of this new PAQ- termed the Madras Diabetes Research Foundation- Physical Activity Questionnaire (MPAQ).
The MPAQ was administered by trained interviewers to 543 individuals of either gender aged 20 years and above from urban and rural areas in 10 states of India from May to August 2011, followed by a repeat administration within a month for assessing reliability. Relative validity was performed against the Global Physical Activity Questionnaire (GPAQ). Construct validity was tested by plotting time spent in sitting and moderate and vigorous physical activity (MVPA) against body-mass index (BMI) and waist circumference. Criterion validity was assessed using the triaxial accelerometer, in a separate subset of 103 individuals. Bland and Altman plots were used to assess the agreement between MPAQ and accelerometer.
The interclass correlation coefficients (ICC) for total energy expenditure and physical activity levels were 0.82 and 0.73 respectively, between baseline and 1st month. The ICC between GPAQ and the MPAQ was 0.40 overall. The construct validity of the MPAQ showed linear association between sitting and MVPA, and BMI and waist circumference independent of age and gender. The Spearman's correlation coefficients for sedentary activity, MVPA and overall PA for MPAQ against the accelerometer were 0.48 (95%CI-0.32-0.62), 0.44 (0.27-0.59) and 0.46 (0.29-0.60) respectively. Bland and Altman plots showed good agreement between MPAQ and accelerometer for sedentary behavior and fair agreement for MVPA.
The MPAQ is an acceptable, reproducible and valid instrument, which captures data from multiple activity domains over the period of a year from adults of both genders and varying ages in various walks of life residing in urban and rural India.
International Journal of Behavioral Nutrition and Physical Activity 12/2015; 12(1). DOI:10.1186/s12966-015-0196-2 · 4.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim:
This study was designed to assess β-cell function and insulin sensitivity indices among normal glucose tolerance (NGT) subjects stratified by 1-h plasma glucose (1hPG) values during an oral glucose tolerance test (OGTT).
Materials and methods:
One hundred sixty-six NGT subjects underwent a five-point OGTT, and glucose and insulin levels were estimated. We calculated the following indices: (a) β-cell function (homeostasis assessment model-β-cell function [HOMA-β] and Insulinogenic Index [IGI]) and (b) insulin sensitivity (homeostasis assessment model-insulin resistance [HOMA-IR], Matsuda Index, and Insulin Sensitivity Index [ISI]).
NGT subgroups with elevated 1hPG values (i.e., 1hPG ≥143 to <155 mg/dL and 1hPG ≥155 mg/dL) did not differ from those with 1hPG <143 mg/dL by HOMA-β (P = 0.236) but had significantly lower IGIs (367 ± 239 vs. 257 ± 243 vs. 246 ± 239; P = 0.019). With respect to ISIs, HOMA-IR was not significantly different among the groups (P = 0.103). However, the Matsuda Index (11.2 ± 5.0 vs. 7.4 ± 4.8 vs. 5.5 ± 4.9; P < 0.001) and ISI (0.015 ± 0.010 vs. 0.012 ± 0.006 vs. 0.011 ± 0.011; P = 0.028) were significantly lower in subjects with elevated 1hPG values.
NGT subjects with elevated 1hPG levels have alterations in β-cell function and insulin sensitivity compared with those with normal 1hPG levels.
[Show abstract][Hide abstract] ABSTRACT: Aim:
To evaluate the sensitivity and specificity of "fundus on phone' (FOP) camera, a smartphone based retinal imaging system, as a screening tool for diabetic retinopathy (DR) detection and DR severity in comparison with 7-standard field digital retinal photography.
Single-site, prospective, comparative, instrument validation study.
301 patients (602 eyes) with type 2 diabetes underwent standard seven-field digital fundus photography with both Carl Zeiss fundus camera and indigenous FOP at a tertiary care diabetes centre in South India. Grading of DR was performed by two independent retina specialists using modified Early Treatment of Diabetic Retinopathy Study grading system. Sight threatening DR (STDR) was defined by the presence of proliferative DR(PDR) or diabetic macular edema. The sensitivity, specificity and image quality were assessed.
The mean age of the participants was 53.5 ±9.6 years and mean duration of diabetes 12.5±7.3 years. The Zeiss camera showed that 43.9% had non-proliferative DR(NPDR) and 15.3% had PDR while the FOP camera showed that 40.2% had NPDR and 15.3% had PDR. The sensitivity and specificity for detecting any DR by FOP was 92.7% (95%CI 87.8-96.1) and 98.4% (95%CI 94.3-99.8) respectively and the kappa (ĸ) agreement was 0.90 (95%CI-0.85-0.95 p<0.001) while for STDR, the sensitivity was 87.9% (95%CI 83.2-92.9), specificity 94.9% (95%CI 89.7-98.2) and ĸ agreement was 0.80 (95%CI 0.71-0.89 p<0.001), compared to conventional photography.
Retinal photography using FOP camera is effective for screening and diagnosis of DR and STDR with high sensitivity and specificity and has substantial agreement with conventional retinal photography.
PLoS ONE 09/2015; 10(9):e0138285. DOI:10.1371/journal.pone.0138285 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background & objectives:
Overweight and obesity are rapidly increasing in countries like India. This study was aimed at determining the prevalence of generalized, abdominal and combined obesity in urban and rural India.
Phase I of the ICMR-INDIAB study was conducted in a representative population of three s0 tates [Tamil Nadu (TN), Maharashtra (MH) and Jharkhand (JH)] and one Union Territory (UT)[Chandigarh (CH)] of India. A stratified multi-stage sampling design was adopted and individuals ≥20 yr of age were included. WHO Asia Pacific guidelines were used to define overweight [body mass index (BMI) ≥23 kg/m  but <25 kg/m ], generalized obesity (GO, BMI≥25kg/m  , abdominal obesity (AO, waist circumference ≥90 cm for men and ≥80cm for women) and combined obesity (CO, GO plus AO). Of the 14,277 participants, 13,800 subjects (response rate, 96.7%) were included for the analysis (urban: n=4,063; rural: n=9737).
The prevalence of GO was 24.6, 16.6, 11.8 and 31.3 per cent among residents of TN, MH, JH and CH, while the prevalence of AO was 26.6, 18.7, 16.9 and 36.1 per cent, respectively. CO was present in 19.3, 13.0, 9.8 and 26.6 per cent of the TN, MH, JH and CH population. The prevalence of GO, AO and CO were significantly higher among urban residents compared to rural residents in all the four regions studied. The prevalence of overweight was 15.2, 11.3, 7.8 and 15.9 per cent among residents of TN, MH, JH and CH, respectively. Multiple logistic regression analysis showed that female gender, hypertension, diabetes, higher socio-economic status, physical inactivity and urban residence were significantly associated with GO, AO and CO in all the four regions studied. Age was significantly associated with AO and CO, but not with GO.
Interpretation & conclusions:
Prevalence of AO as well as of GO were high in India. Extrapolated to the whole country, 135, 153 and 107 million individuals will have GO, AO and CO, respectively. However, these figures have been estimated from three States and one UT of India and the results may be viewed in this light.
The Indian Journal of Medical Research 09/2015; 142(2):139-50. DOI:10.4103/0971-5916.164234 · 1.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim:
To estimate the prevalence of, and assess factors associated with, diabetes and prediabetes in three South Asian cities.
Using a multi-stage cluster random sample representative of each city, 16,288 subjects aged ≥20 years (Chennai: 6906, Delhi: 5365 and Karachi: 4017) were recruited to the Centre for cArdio-metabolic Risk Reduction in South-Asia (CARRS) Study. Fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) were measured in 13720 subjects. Prediabetes was defined as FPG 100-125mg/dl (5.6-6.9mmol/l) and/or HbA1c 5.7-6.4% (39-46mmol/mol) and diabetes as self-report and/or drug treatment for diabetes and/or FPG≥126mg/dl (≥7.0mmol/l) and/or HbA1c≥6.5% (48mmol/mol). We assessed factors associated with diabetes and prediabetes using polytomous logistic regression models.
Overall 47.3-73.1% of the population had either diabetes or prediabetes: Chennai 60.7% [95%CI: 59.0-62.4%] (diabetes - 22.8% [21.5-24.1%], prediabetes - 37.9% [36.1-39.7%]); Delhi 72.7% [70.6-74.9%] (diabetes - 25.2% [23.6-26.8%], prediabetes - 47.6% [45.6-49.5%]); and Karachi 47.4% [45.7-49.1%]; (diabetes - 16.3% [15.2-17.3%], prediabetes - 31.1% [29.5-32.8%], respectively). Proportions of self-reported diabetes were 55.1%, 39.0%, and 48.0% in Chennai, Delhi, and Karachi, respectively. City, age, family history of diabetes, generalized obesity, abdominal obesity, body fat, high cholesterol, high triglyceride, and low HDL cholesterol levels were each independently associated with prediabetes, while the same factors plus waist-to-height ratio and hypertension were associated with diabetes.
Six in ten adults in large South Asian cities have either diabetes or prediabetes. These data call for urgent action to prevent diabetes in South Asia.
Diabetes research and clinical practice 09/2015; DOI:10.1016/j.diabres.2015.09.005 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim:
To validate the stability of glycated haemoglobin (HbA1c) measurements in blood samples stored at -20°C for up to one month.
The study group comprised 142 type 2 diabetic subjects visiting a tertiary centre for diabetes at Chennai city in south India. The HbA1c assay was done on a fasting blood sample using the Bio-Rad Variant machine on Day 0 (day of blood sample collection). Several aliquots were stored at -20°C and the assay was repeated on the 3rd, 7th, 15th, and 30th day after the sample collection. Bland-Altman plots were constructed and variation in the HbA1c levels on the different days was compared with the day 0 level.
The median differences between HbA1c levels measured on Day 0 and the 3rd, 7th, 15th, and 30th day after blood collection were 0.0%, 0.2%, 0.3% and 0.5% respectively. Bland-Altman plot analysis showed that the differences between the day '0' and the different time points tend to get larger with time, but these were not clinically significant.
HbA1c levels are relatively stable up to 2weeks, if blood samples are stored at -20°C.
Journal of diabetes and its complications 09/2015; DOI:10.1016/j.jdiacomp.2015.09.014 · 3.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is well known that inflammation is associated with diabetes, but it is unclear whether obesity mediates this association in individuals with youth-onset type 2 diabetes (T2DM-Y).
We recruited age-matched individuals with type 2 diabetes (age at onset <25 years) and normal glucose tolerance youth. Participants were further classified using Asia-Pacific body mass index cut-points for obesity and categorized as: Non-Obese NGT (n=100), Obese-NGT (n=50), Non-Obese T2DM-Y (n=50), and Obese-T2DM-Y (n=50). We compared adipokines (adiponectin and leptin) and proinflammatory cytokines (tumour necrosis factor alpha [TNF -α], monocyte chemotactic protein-1 [MCP-1]) across groups.
Compared to non-obese NGT, the other three groups viz, obese NGT, non-obese T2DM-Y, and obese T2DM-Y were found to have lower adiponectin (7.7 vs. 5.7, 4.2, 3.8 μg/mL, p<0.01), and higher leptin (3.6 vs. 5.4, 5.7, 7.9 μg/ml, p<0.001) and MCP 1 (186 vs. 272, 340, 473 pg/ml, p<0.001) respectively. However, TNF-α levels were higher only among non obese T2DM-Y (112 pg/ml) and obese T2DM-Y (141 pg/ml, p<0.01 for each). After adjusting for age, gender, waist, hypertension, HOMA-IR, serum cholesterol, triglycerides, and family history of diabetes, adiponectin was associated with 33% and 41% lower odds of being non-obese T2DM and obese T2DM, respectively. However, adjusted for same factors, leptin, TNF- α, and MCP-1 were associated with markedly higher odds (5 to 14-fold) of non-obese T2DM and obese T2DM.
In young Asian Indians, leptin and proinflammatory cytokines are positively, and adiponectin negatively, associated with both non obese and obese T2DM-Y compared to non-obese NGT individuals.
Endocrine Practice 07/2015; DOI:10.4158/EP15741.OR · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Retinol binding protein 4 (RBP4) has been implicated in metabolic disorders including type 2 diabetes, but few studies have looked at transthyretin (TTR) with which RBP4 normally bound in the circulation. We report on the systemic levels of RBP4, TTR and their association with insulin resistance, obesity, prediabetes and type 2 diabetes in Asian Indians.
Age matched individuals with normal glucose tolerance [NGT; n=90], impaired glucose tolerance [IGT; n=70] and type 2 diabetes mellitus [T2DM; n=90] were recruited from the Chennai Urban Rural Epidemiology Study (CURES). Insulin resistance was estimated using the homeostasis model assessment (HOMA-IR). RBP4 and TTR levels were measured by ELISA.
Circulatory RBP4 and TTR levels were highest in T2DM (RBP4: 13 ± 3.9; TTR: 832 ± 310 μg/ml) followed by IGT (RBP4: 10.5 ± 3.2; TTR: 720 ± 214) compared to NGT (RBP4: 8.7± 2.5; TTR: 551 ± 185; p<0.001). Compared to non-obese NGT individuals, obese NGT, non-obese T2DM, and obese T2DM had higher RBP4 (8.1 vs. 10.6, 12.1 & 13.2 μg/mL, p<0.01) and TTR levels (478 vs. 737, 777 & 900 μg/mL, p<0.01). RBP4, but not TTR, was significantly (p<0.001) correlated with insulin resistance even among NGT subjects. In regression analysis, RBP4 and TTR showed significant association with T2DM after adjusting for confounders (RBP4 - OR: 1.107 95% CI: 1.008 - 1.216; TTR - OR: 1.342 95% CI: 1.165 - 1.547).
Circulatory levels of RBP4 and TTR showed a significant association with glucose intolerance, obesity and T2DM, and RBP4 additionally, with insulin resistance.
Endocrine Practice 06/2015; DOI:10.4158/EP14558.OR · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Diabetes has been defined on the basis of different bio-markers, including fasting plasma glucose (FPG), 2-h plasma glucose in an oral glucose tolerance test (2hOGTT), and HbA1c. We assessed the effect of different diagnostic definitions on both the population prevalence of diabetes and the classification of previously undiagnosed individuals as having diabetes versus not having diabetes in a pooled analysis of data from population-based health examination surveys in different regions.
We used data from 96 population-based health examination surveys that had measured at least two of the bio-markers used for defining diabetes. Diabetes was defined using HbA1c (HbA1c ≥6·5% or history of diabetes diagnosis or using insulin or oral hypoglycemic drugs) compared with either FPG only or FPG-or-2hOGTT definitions (FPG ≥7·0 mmol/L or 2hOGTT ≥11·1 mmol/L or history of diabetes or using insulin or oral hypoglycemic drugs). We calculated diabetes prevalence, taking into account complex survey design and survey sample weights. We compared the prevalences of diabetes using different definitions graphically and by regression analyses. We calculated sensitivity and specificity of diabetes diagnosis based on HbA1c compared with diagnosis based on glucose among previously undiagnosed individuals (i.e., excluding those with history of diabetes or using insulin or oral hypoglycemic drugs). We calculated sensitivity and specificity in each survey, and then pooled results using a random-effects model. We assessed the sources of heterogeneity of sensitivity by meta-regressions for study characteristics selected a priori.
Population prevalence of diabetes based on FPG-or-2hOGTT was correlated with prevalence based on FPG alone (r=0·98), but was higher by 2–6 percentage points at different prevalence levels. Prevalence based on HbA1c was lower than prevalence based on FPG in 42·8% of age–sex–survey groups and higher in another 41·6%; in the other 15·6%, the two definitions provided similar prevalence estimates. The variation across studies in the relation between glucose-based and HbA1c-based prevalences was partly related to participants' age, followed by natural logarithm of per person gross domestic product, the year of survey, mean BMI, and whether the survey population was national, sub-national, or from specific communities. Diabetes defined as HbA1c 6·5% or more had a pooled sensitivity of 52·8% (95% CI 51·3–54·3%) and a pooled specificity of 99·74% (99·71–99·78%) compared with FPG 7·0 mmol/L or more for diagnosing previously undiagnosed participants; sensitivity compared with diabetes defined based on FPG-or-2hOGTT was 30·5% (28·7–32·3%). None of the preselected study-level characteristics explained the heterogeneity in the sensitivity of HbA1c versus FPG.
Different biomarkers and definitions for diabetes can provide different estimates of population prevalence of diabetes, and differentially identify people without previous diagnosis as having diabetes. Using an HbA1c-based definition alone in health surveys will not identify a substantial proportion of previously undiagnosed people who would be considered as having diabetes using a glucose-based test.
[Show abstract][Hide abstract] ABSTRACT: India has the second largest number of people with diabetes in the world following China. Evidence indicates that consumption of whole grains can reduce the risk of type 2 diabetes. This article describes the study design and methods of a trial in progress evaluating the effects of substituting whole grain brown rice for polished (refined) white rice on biomarkers of diabetes risk (glucose metabolism, dyslipidemia, inflammation). This is a randomized controlled clinical trial with a crossover design conducted in Chennai, India among overweight but otherwise healthy volunteers aged 25–65 y with a body mass index ≥23 kg/m2 and habitual rice consumption ≥200 g/day. The feasibility and cultural appropriateness of this type of intervention in the local environment will also be examined. If the intervention is efficacious, the findings can be incorporated into national-level policies which could include the provision of brown rice as an option or replacement for white rice in government institutions and food programs. This relatively simple dietary intervention has the potential to substantially diminish the burden of diabetes in Asia and elsewhere.
International Journal of Food Sciences and Nutrition 05/2015; DOI:10.3109/09637486.2015.1038225 · 1.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim:
To investigate insulin sensitivity and insulin secretion patterns among Asian Indian youth without and with type 2 diabetes (T2DM-y defined as onset of diabetes at or below 25 years) with normal and high visceral fat (VF) levels.
We recruited 74 T2DM-y individuals, within 18 months of diagnosis and compared them to 77 age-matched controls with normal glucose tolerance (NGT). Using L4/L5 abdominal CT images, VF levels were categorized as normal or high according to their median values. Oral glucose tolerance tests (glucose and insulin measures) were used to derive Matsuda index, insulin resistance (HOMA-IR) and oral disposition index (DIo). Relationships between measures of insulin sensitivity and secretion and T2DM-y by VF level were assessed using standardized multinomial regression models.
Participants were categorized into four groups: NGT-normal VF; NGT-high VF; T2DM-normal VF, and T2DM-high VF. Among NGTs, those with high VF had significantly lower insulin sensitivity (0.013 vs.0.019 pM(-1)) and Matsuda index (10.2 vs.13.8), than normal VF. When compared, T2DM-high VF had lowest insulin sensitivity (0.009 vs.0.019, 0.013, 0.012 pM-1; p<0.001), Matsuda index (6.4 vs. 13.8, 10.2, 8.6; p<0.001), OGIS120 (305 vs. 396, 382, 316; p<0.001) and DIo (0.48 vs. 3.75, 3.20, 0.55 mmol/L; p<0.001). At every category of 2 h PG values, NGT-high VF had lower DIo than NGT-normal VF participants. In standardized multinomial models, that included DIo and Matsuda index adjusted for age, gender, BMI, and leptin, DIo (Odds ratio: 0.001; 95%Confidence interval: 0.000-0.020), matsuda index (0.26; 0.07-0.93), age (2.92; 1.18-7.19) and leptin (3.17; 1.12-8.99) were associated with high VF among T2DM.
Lower DIo and Matsuda index, younger age and higher leptin were independently associated with high visceral fat among T2DM participants. Also, lower DIo was seen with increasing 2 h PG values even among normal glucose tolerant individuals.
Diabetes research and clinical practice 05/2015; 109(1). DOI:10.1016/j.diabres.2015.05.018 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Reduced muscular strength, as measured by grip strength, has been associated with an increased risk of all-cause and cardiovascular mortality. Grip strength is appealing as a simple, quick, and inexpensive means of stratifying an individual's risk of cardiovascular death. However, the prognostic value of grip strength with respect to the number and range of populations and confounders is unknown. The aim of this study was to assess the independent prognostic importance of grip strength measurement in socioculturally and economically diverse countries.
The Lancet 05/2015; 386(9990). DOI:10.1016/S0140-6736(14)62000-6 · 45.22 Impact Factor