Increasing prevalence of type 2 diabetes in a Scottish population: Effect of increasing incidence or decreasing mortality?

Division of Community Health Sciences, University of Dundee Medical School, Dundee, Scotland, UK.
Diabetologia (Impact Factor: 6.67). 05/2007; 50(4):729-32. DOI: 10.1007/s00125-006-0585-9
Source: PubMed


We examined incidence, prevalence and mortality from type 2 diabetes mellitus in a Scottish population over 12 years, and evaluated the effects on prevalence of increasing incidence and decreasing mortality.
We used a diabetes clinical information system in Tayside (population 387,908), Scotland, to identify new cases of type 2 diabetes between 1993 and 2004 and to calculate incidence rates and mid-year prevalence. We defined mortality rates as the number of deaths of diabetic people divided by mid-year prevalence. We used logistic and Poisson regression to analyse trends. We then modelled the increase in prevalence for each year for three scenarios, based on whether mortality or incidence rates remained unchanged from 1993.
There was a doubling in incidence and prevalence of type 2 diabetes in Tayside over the 12 years, with statistically significant increasing trends of 6.3 and 6.7% per year respectively. The mortality rate decreased. If incidence and mortality had remained at 1993 levels, there would have been an increase in prevalence of 855 per 100,000 in 2003, accounting for 60.1% of the actual increase of 1,423 per 100,000. If there had been no mortality decrease, prevalence in 2003 would have been very similar to the actual prevalence observed.
Decreasing mortality rates in Tayside had less effect on the increase in prevalence than did increasing incidence. Even if incidence and mortality remain unchanged, prevalence will increase by over 20% in the next decade.

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Available from: Josie Evans, Jan 29, 2014
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    • "Similar findings were reported from Denmark; Carstensen et al [8] showed that the incidence increased by 5% per year between 1995 and 2004. Increasing incidence has also been reported from other parts of Europe [3]–[4], [22] and the US [2]; In a Scottish study, a doubling of the incidence of type 2 diabetes was seen 1993–2004 [22] and in the UK, incidence of type 2 diabetes rose by two thirds 1996–2005 [3] and in the US incidence of diabetes doubled 1980–2011 [2]. "
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    ABSTRACT: Background Diabetes is on the rise in the western world, but data from Scandinavia are inconsistent with indications of stable or even reverse trends. To shed new light on this issue, we investigated diabetes trends in Stockholm County 1990–2010, taking into account trends in risk factors and mortality. Methods We used data from a large population-based quadrennial public health survey conducted between 1990 and 2010 in Stockholm County (∼2.1 million inhabitants), supplemented with data from national registers. The age-standardized prevalence and incidence rates of diabetes and related risk factors 1990–2010 were estimated in adult inhabitants. We also modelled the influence of potential risk factors on the diabetes trends and estimated the life time risk of diabetes. Results The prevalence of diabetes was 4.6% (95% confidence interval (CI); 4.5–4.8%) in 2010 compared to 2.8% (95% CI; 2.3–3.5%) in 1990. Between 1990 and 2002 the prevalence rose annually by 3.8% (95% CI; 2.1–5.5). Incidence rates showed a similar pattern and rose by 3.0% (95% CI; 0.3–5.7%) annually 1990–2002. The rising incidence was mainly attributable to increasing prevalence of overweight/obesity, which rose by 46% during the observation period. In 2010, the lifetime risk of adult onset diabetes was 28% (95% CI; 26–31%) in men and 19% (95% CI; 17–21%) in women. Conclusions Diabetes rates have been increasing in Stockholm over the last decades, both in terms of incidence and prevalence, and this development is most likely the result of increasing overweight and obesity in the population.
    Full-text · Article · Aug 2014 · PLoS ONE
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    • "These data together with the reported increase of diabetes prevalence in the UK [11], [26] suggest that visual impairment due to diabetes complications continues to be a major public health issue. Additional analyses to evaluate risk factors associated with the occurrence of diabetic retinopathy under contemporary diabetes management protocols are needed to develop effective preventive strategies and treatment. "
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    ABSTRACT: Purpose We aimed at estimating the incidence of diabetic retinopathy (DR) and maculopathy (DMP) among newly diagnosed type 1 (t1DM) and type 2 diabetic patients (t2DM) in the United Kingdom primary care system. The incidence of DMP among patients with DR was also estimated. Method We conducted a cohort study using The Health Improvement Network database. The cohort included 64,983 incident diabetic patients (97.3% were t2DM) aged 1–84 years diagnosed between 2000 and 2007. This cohort was followed from the date of diabetes diagnosis until recording of DR or DMP in two separate follow-ups. Follow-up was censored at 85 years of age, death, or end of 2008. An additional follow-up was conducted from DR to DMP diagnosis using similar censoring reasons. DR and DMP cumulative incidences were calculated as well as incidence rates (IR; cases per 1,000 person-years) per calendar period (2000–2001 and 2006–2007). Results Follow-up for DR: 9 years after diabetes diagnosis, 28% of t2DM and 24% of t1DM patients had developed DR (7,899 incident DR cases). During the first 2 years with diabetes, the IR was almost 2 times higher in patients diagnosed with diabetes in 2006–2007 (47.7) than among those diagnosed in 2000–2001 (24.5). Follow-up for DMP: 9 years after diabetes diagnosis, 3.6% of t2DM and 4.4% of t2DM patients had developed DMP (912 incident DMP cases). During the first 2 years with diabetes, the IR was three times higher in patients diagnosed with diabetes in 2006–2007 (5.8) than among those diagnosed in 2000–2001 (1.8). Macular oedema occurred in 0.8% of patients. Conclusions In a cohort of incident diabetes, 28% of patients developed retinopathy and 4% maculopathy within the first 9 years. The 2-year IRs of DR and DMP were higher in patients diagnosed with diabetes during the period 2006–2007 than in those diagnosed during the 2000–2001 period.
    Full-text · Article · Jun 2014 · PLoS ONE
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    • "For example, increased survival among those with the diagnosis will increase the prevalence [11] and higher life expectancy (ageing) in the general population could influence the incidence. Others have shown that declining mortality among patients may contribute, but that increasing incidence was the main driver of the increasing prevalence over time, at least in Denmark 1992–2003 [7] and in Scotland 1993–2004 [5]. We did not have mortality data in our study but others have shown a secular decrease in mortality from ischaemic heart disease among patients with diabetes in Norway [12], suggesting that this could have contributed to the observed increasing prevalence with concurrent decline in incidence. "
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    ABSTRACT: Background National estimates for the occurrence of diabetes are difficult to obtain, particularly time trends in incidence. The aim was to describe time trends in prevalent and incident use of blood glucose-lowering drugs by age group and gender in Norway during 2005–2011. Methods Data were obtained from the nationwide Norwegian Prescription Database. We defined prevalent users of “insulins only” as individuals having no oral antidiabetic drugs (OAD) dispensed from a pharmacy during the previous 24 months or in the subsequent 12 months. Incident users had no blood glucose-lowering drugs dispensed in the previous 24 months; incident “insulins only” users also had no OAD in the subsequent 12 months. Results In 2011, 3.2% of the population had blood glucose-lowering drugs dispensed, and the incidence rate was 313 per 100,000 person years. The prevalence of OAD use increased from 1.8% in 2005 to 2.4% in 2011; however a decreasing trend in incidence of OAD use was observed, particularly in those aged 70 years and older. In 2010, 0.64% of the population had insulins only dispensed, with an overall incidence rate in the total population of 33 per 100,000 person years which was stable over time. Conclusions In this nationwide study, we found that although the prevalent use of OAD had increased in recent years, incident use was stable or had decreased. This may indicate that the increase in diabetes occurrence in Norway is levelling off, at least temporarily.
    Full-text · Article · May 2014 · BMC Public Health
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