The increase in men’s average body mass index (BMI) accounts for a large proportion of the rise in Type 2 diabetes among men in the UK over the past few decades, say researchers.

However, around three quarters of new cases of Type 2 diabetes that occurred during this time cannot be explained by increasing BMI, suggesting that other factors such as lack of physical activity may also play a role.

Sarah Hardoon (University College London, UK) and colleagues followed-up a cohort of 6460 UK men for incidence of Type 2 diabetes. They were enrolled when aged 45-65 years, during 1984-1992, and were followed-up until 2007 when aged 67-89 years.

The age-adjusted incidence of Type 2 diabetes in the cohort increased a significant 2.33-fold between the two time periods.

The team found that mean BMI also increased significantly between 1984 and 1999 by 1.42 kg/m² and they suggest this is likely to explain approximately 26% of the observed increase in Type 2 diabetes.

“Control and reversal of the rise in adiposity levels is therefore an important priority in controlling the diabetes epidemic,” say Hardoon et al.

The researchers acknowledge that a large proportion of the increase in Type 2 diabetes remains unexplained, but say that declining physical activity levels and dietary factors are also likely to be implicated.

“Physical activity has a strong protective effect on Type 2 diabetes risk, which operates at least partly independently of BMI,” they explain.

In addition: “Dietary factors associated with reducing Type 2 diabetes risk include a high fiber diet, and daily consumption of fiber declined between 1987 and 2000.”

Writing in the journal Diabetes Care, the team suggests: “The presence of other contributing factors would suggest the need for a more multifactorial approach to combat rising Type 2 diabetes in the population.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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The prevalence of Type 2 diabetes among UK men has risen by 10.9% over the past three decades, with a dramatic increase in more recent years accounting for a large proportion of the overall increase, report UK researchers.

Prevalence of the condition has increased sharply worldwide in recent years, and researchers predict that the disease is likely to reach epidemic proportions during this century, explain Mary Thomas (University College London) and colleagues.

For this study, Thomas and co-investigators used data collected from a cohort of 7722 British men from across the UK, aged 40 “59 years at baseline, who were followed-up from 1978 “2005 for incidence of Type 2 diabetes.

The researchers carried out seven sequential surveys during the study period. Diagnosis of diabetes was defined by self-reported diagnosis of diabetes or self-reported use of anti-diabetes medication on returned questionnaires.

Writing in the journal Diabetic Medicine, the researchers report that the prevalence of Type 2 diabetes increased from just 1.2% in 1978 to 12.1% in 2005.

They calculated that the average age-adjusted increase in Type 2 diabetes prevalence over the study period was 7.0%.

However, the increase in prevalence was not uniform as the annual rate of increase from 1979 “2000 ranged from 4.3% to 6.9%, but increased dramatically to an average of 11.2% in the 2000 “2005 period.

Men from Scotland had the greatest increase in prevalence of Type 2 diabetes, with the lowest UK prevalence ” 0.52% ” in 1979 and the highest UK prevalence ” 13.0% ” in 2005.

The authors note that the rate of increase was strongly related to body mass index (BMI), with annual rates of increase rising with increasing BMI. Individuals with a BMI below 22.5 kg/m² had an annual increase of less than 3% compared with a higher than 10% annual increase in men with a BMI of 27.5 kg/m² or more.

Thomas et al estimate that if all participants had maintained a BMI of under 25 kg/m² for the entire duration of the study, 68% of diabetes cases would have been prevented.

“These results emphasize the urgency of population-wide measures to control the increase in Type 2 diabetes prevalence, particularly by limiting the rising prevalence of obesity at all ages,” concludes the team.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009

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