Spotlight on body weight and diabetes complications
A systematic review found that weight gain was associated with increased cardiovascular risk in type 2 diabetes patients but that the effects of intentional weight loss were unclear, while another analysis found that higher body mass index was mostly not associated with cancer mortality.
Two recent studies looked for associations between body weight and outcomes in patients with type 2 diabetes.
The first, published by Diabetologia on Dec. 2, was a systematic review of studies of weight loss and other weight changes and the effects on incidence of cardiovascular disease (CVD) among patients with type 2 diabetes. It included 17 studies (14 observational studies and three trials), with sample sizes ranging from 444 to 173,246 patients. The systematic review found that gaining weight was associated with significantly higher risk of a CVD event (hazard ratios [HRs] ranging from 1.13 to 1.63) and all-cause mortality (HRs from 1.26 to 1.57) than maintaining the same weight. Unintentional weight loss was associated with higher risk of all-cause mortality, but there was no clear effect of intentional weight loss on CVD or mortality. “Behavioral interventions targeting weight loss showed no effect on CVD events,” the authors wrote. Based on the results, they concluded that preventing weight gain among people with type 2 diabetes may help to reduce the burdens of CVD and premature mortality but that there is limited evidence that weight-loss interventions deliver long-term cardiovascular health benefits. They called for additional research “to identify patient groups that will achieve lower CVD event rates following weight loss, and to determine how much weight loss should be achieved and for how long this should be maintained.”
An analysis in England, published by Diabetes, Obesity and Metabolism on Dec. 6, used a national database to look at cancer mortality among 176,886 adult patients with type 2 diabetes. During 886,850 person-years of follow-up, 7,593 cancer deaths occurred, and most types of cancer showed an inverse relationship with body mass index (BMI) in patients with diabetes. However, in women with diabetes who never smoked, there were positive associations between BMI and death from endometrial cancer (HR per 5 kg/m2, 1.43; 95% CI, 1.26 to 1.61) and possibly ovarian cancer (HR per 5 kg/m2, 1.13; 95% CI, 1.01 to 1.27). In men who never smoked, there were inverse associations between BMI and death from obesity-related cancer. Death from CVD was positively associated with BMI in men, and this competing cause of death “may partly explain a lack of association between BMI and cancer mortality in men,” the authors said. The absence of more association between BMI and cancer in the study results suggests “that the associations between BMI and cancer mortality are specific for obesity-related cancers,” the authors also noted, concluding that their data “add information to the rationale for weight control management.”