Weight loss increases all-cause mortality in overweight or obese patients with diabetes: A meta-analysis

Overweight and obese patients with diabetes are advised to lose weight to improve their health; however, recent studies have demonstrated that weight loss may be associated with worse long-term survival in patients with diabetes. This meta-analysis aimed to examine the relationships between weight loss and all-cause mortality in overweight or obese individuals with diabetes.

We searched the PubMed and EMBASE databases from inception to February 2017. We included prospective studies that reported sufficient information to extract mortality-specific relative risks (RRs) with corresponding 95% confidence intervals (CIs). RRs with 95% CIs were pooled using a random-effects model. A subgroup analysis was also performed to explore sources of heterogeneity.

Of the 1652 studies identified, 8 met the inclusion criteria. A total of 18,887 patients were included in this analysis. We found that compared with a stable weight, weight loss was associated with an increased risk of all-cause mortality (RR, 1.15; 95% CI, 1.04 to 1.28) and cardiovascular disease (CVD) mortality (RR, 1.15; 95% CI, 1.02 to 1.29) in overweight or obese adults with diabetes, whereas intentional weight loss was not associated with changes in all-cause mortality (RR, 0.90; 95% CI, 0.67 to 1.22). Weight gain was not associated with changes in all-cause mortality (RR, 1.17; 95% CI, 0.87 to 1.58) or CVD mortality (RR, 0.97; 95% CI, 0.93 to 1.01). Compared with an initial body mass index (BMI) of 25 to 30 kg/m, an initial BMI of >35 kg/m was associated with increased all-cause mortality (RR, 1.23; 95% CI, 1.01 to 1.50), which was further increased with an initial BMI of >40 kg/m (RR, 1.50; 95% CI, 1.16 to 1.94).

Our results indicate that weight loss but not weight gain increased all-cause mortality and CVD mortality in overweight or obese adults with diabetes.