Obesity Increases Risk of Type 2 Diabetes Over Time, Study Finds

The study is more evidence that obesity is not just linked to type 2 diabetes but may cause it to occur.

A study just published in the leading journal Diabetes Care found that patients who carried more body weight were more likely to develop type 2 diabetes mellitus (T2DM), even in the absence of metabolic dysfunction.

The analysis adds to the evidence of the relationship between diabetes and obesity, both of which have increased in recent decades in the United States. Diabetes Care is published by the American Diabetes Association.

Authors led by Bas T. Franssens, tracked a cohort of 6997 patients for a median follow-up of 6.0 years. The study, formally called Secondary Manifestation of ARTerial disease or SMART, classified patients according to their body mass index (BMI) and their level of metabolic dysfunction, which was defined as 3 or more of the modified criteria under the National Cholesterol Education Program (NCEP). Risk of developing T2DM was assessed twice a year.

According to the CDC, patients with a BMI of 25 to 29.9 are overweight, while those with a BMI of 30 or above are obese. Those with a BMI of 18.5 to 24.9 are in the normal range.

During the study period, 519 patients developed T2DM. In the absence of metabolic dysfunction, with 2 or fewer of the NCEP criteria present, increased body weight increased the likelihood of T2DM, compared with normal weight patients: HR 2.5 [95% CI 1.5-4.2] for overweight and HR 4.3 [95% CI 2.2-7.8] for obese patients.

In the presence of metabolic dysfunction, using 3 or more of the NCEP criteria present, an increased risk of T2DM was seen in patients with normal weight (HR 4.7 [95% CI 10.4-25.6]), and in those who were overweight (HR 8.5 [95% CI 5.5-13.4]) or obese (HR 16.3 [95% CI 10.4-25.6]), relative to patients with normal weight and no metabolic dysfunction.

The authors conclude that adiposity, or increased body weight, is an independent risk factor for developing T2DM, regardless of underlying metabolic status. This, they wrote, “supports the assessment of adiposity and metabolic dysfunction in patients with vascular disease or at high risk for cardiovascular events.”

Reference

Franssens BT, van der Graaf Y, Kappelle JL, et al. Body weight, metabolic dysfunction, and risk of type 2 diabetes in patients at high risk for cardiovascular events or with manifest cardiovascular disease: a cohort study [published online August 25, 2015]. Diabetes Care. 2015; doi: 10.2337/dc14-0684.