Study explores waist circumference's link to mortality risk in diabetic individuals

Background and objectives

Waist circumference (WC) is closely associated with metabolic diseases, including diabetes mellitus (DM), metabolic syndrome, and mortality. However, the correlation between WC and mortality varies across populations and has rarely been examined specifically in patients with DM. In this study, we explored the relationships between WC and both all-cause and cardiovascular mortalities among individuals with DM.

Methods

Participants from the National Health and Nutrition Examination Survey 2003–2018 included 3,151 women and 3,473 men with DM who had baseline WC measurements. Survival data were collected from enrollment until December 31, 2019. Cox proportional hazard models were adjusted for demographic features and other confounders. Restricted cubic spline curves and threshold effect analyses were performed separately for men and women. Sensitivity analyses were conducted to minimize reverse causality.

Results

Among 6,624 participants with DM, 621 women and 871 men died during median follow-ups of 6.8 and 6.3 years, respectively. WC demonstrated a U-shaped association with all-cause and cardiovascular mortalities in women, and a J-shaped trend in men. The optimal WC thresholds for minimizing mortality risk were 107.0 cm for women and 89.0 cm for men. For women, adjusted hazard ratios for all-cause mortality were 0.97 (95% confidence interval (CI): 0.96–0.98, P < 0.001) for WC below 107.0 cm and 1.04 (95% CI: 1.02–1.05, P < 0.001) for WC above 107.0 cm. In men, the corresponding ratios were 0.94 (95% CI: 0.90–0.97, P < 0.001) for WC below 89.0 cm and 1.03 (95% CI: 1.02–1.05, P < 0.001) for WC above 89.0 cm.

Conclusions

WC showed a U-shaped association with all-cause and cardiovascular mortalities in women and a J-shaped association in men among U.S. adults with DM from the National Health and Nutrition Examination Survey. Further research is needed to explore the underlying mechanisms rather than promoting preconceived notions about an optimal WC.