Depressive symptoms, all-cause mortality, and cardiovascular-specific mortality among adults with different diabetic status in the United States.

ObjectiveThe relationship between diabetes, depressive symptoms, and mortality is well established. However, the effect of depressive symptoms on mortality among people with prediabetes remains unclear. This study examined the effects of depressive symptoms on mortality across different diabetic statuses.MethodsData were analyzed from cross-sectional samples collected as part of the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018, with a final sample size of 36,246 participants. Mortality status and cause of death were prospectively determined by cross-referencing records with the publicly accessible National Death Index through 2019. Kaplan-Meier survival curves and Cox regression analysis were utilized to assess the relationship between depressive symptoms and mortality across different diabetic statuses from nondiabetic to prediabetic to diabetic.ResultsIn the non-diabetic group, no effect of depression severity on all-cause mortality or cardiovascular mortality was found in the final models. In the prediabetic group, however, the hazard ratios were increased for both mild depressive symptoms (HR = 1.35, 95% CI = 1.14-1.60) and moderate-to-severe depressive symptoms (HR = 1.65, 95% CI = 1.31-2.08). In the diabetic group, surprisingly, the all-cause mortality risk was somewhat lower than in the pre-diabetic group (HR = 1.28, 95% CI = 1.08-1.51 for mild and HR = 1.29, 95% CI = 1.06-1.56 for moderate-to-severe depressive symptoms). Similar patterns were noted for cardiovascular mortality, where risk of moderate-severe depressive symptoms was even greater in the prediabetic group (HR = 1.83, 95% CI = 1.18-2.85) than in the diabetic group.ConclusionIn this prospective cohort study of a nationally representative sample of U.S. adults, a positive association was found between depressive symptoms and mortality across different diabetic statuses. These findings highlight the importance of evaluating depressive symptoms across the glycemic spectrum, especially among individuals with prediabetes.