Weight status and all-cause mortality in older adults: A study of patients with type 2 diabetes undergoing subtotal gastrectomy for cancer

Abstract

Background: The survival benefit of excess body weight is controversial across various subpopulations. We assessed the effect of weight status on all-cause mortality among patients with type 2 diabetes (T2DM) undergoing subtotal gastrectomy for gastric cancer. Methods: Medical charts of 210 patients with T2DM treated at 2 university hospitals were examined retrospectively. All patients had undergone subtotal gastrectomy for cancer between January 1993 and December 2012. Participants were categorized as normal weight (body mass index [BMI], 18.5-24.99 kg/m2) or overweight/obese (BMI≥25 kg/m2). The association between weight status and all-cause mortality was assessed using weighted Cox proportional hazard regression models and inverse probability weighting. Results: The mortality rate was 25.2% after a median follow-up duration of 6.1 years (in-terquartile range, 3.5-8.3 years; maximum, 14.4 years). The overweight/obese group had a significantly lower risk of all-cause mortality (hazard ratio, 0.51; 95% confidence interval, 0.34-0.77; p=0.001) compared with the normal weight group. Overweight/obesity was associated with reduced all-cause mortality in patients aged <65 years (p=0.01 for interaction). Conclusion: Among T2DM patients who underwent subtotal gastrectomy for cancer, only the subgroup of patients aged <65 years in the overweight/obese group showed reduced all-cause mortality compared with the normal weight group.