Diabetes increases largely explained by BMI growth, especially in women

Since the late 1970s, diabetes prevalence has increased significantly more in men than women, and only in women did changes in body mass index (BMI) fully explain the diabetes trend.

Researchers used cross-sectional data from 5 of the National Health and Nutrition Examination Surveys (NHANES), starting with 1976-1980 and ending with 2007-2010. More than 20,000 adult patients age 20 to 74 were included and diabetes was defined as either a self-reported diagnosis or a fasting plasma glucose level of 126 mg/dL (7.0 mmol/L) or higher. Results were published in Annals of Internal Medicine on Sept. 2.

Diabetes prevalence rates among men increased from 4.7% in the first survey to 11.2% in the last, and among women, the rates were 5.7% and 8.7%, respectively. Adjusting for changes in age, race/ethnicity, and BMI eliminated the increase in women (7.6% versus 7.5%), but in men, the increase was only halved (6.2% in first survey to 9.6% in the last). Researchers concluded that diabetes has increased more in men than women and that change in BMI appears to be the most important factor in this trend, although it does not fully explain the increase in men having diabetes.

Other possible factors that couldn't be assessed from the NHANES data include physical activity, waist circumference, diet, sun exposure, sleep time, stress and depression, and exposure to pollutants and toxins, the researchers noted. Changes in mortality from diabetes could also have affected the findings. The study's results suggest an urgent need for research into the causes of the diabetes increase among men. In addition, the findings support ongoing public health efforts to address obesity, the authors concluded.