The joint association of diabetes distress and depressive symptoms with all-cause mortality in Japanese individuals with type 2 diabetes: a prospective cohort study (Diabetes Distress and Care Registry in Tenri [DDCRT 20]).

The independent association of depressive symptoms and diabetes distress with mortality risk in individuals with diabetes has not been evaluated. We examined the temporal joint association of diabetes distress and depressive symptoms at baseline and the subsequent risk of all-cause mortality. The longitudinal data of 3118 individuals with type 2 diabetes were obtained from a large Japanese diabetes registry. To assess the joint association of diabetes distress and depressive symptoms at baseline with the subsequent risk of all-cause mortality, the Cox proportional hazards model was used with adjustment for potential confounders. The mean age, BMI and HbA1c levels were 64.7 years, 24.6 kg/m2 and 58.6 mmol/mol (7.5%), respectively, and 38.1% of the participants were women. In the multivariable-adjusted models evaluating the diabetes distress and depressive symptoms separately, the HRs for all-cause mortality were 1.67 (95% CI 1.14, 2.43; p = 0.008) and 1.40 (95% CI 1.05, 1.85; p = 0.020), respectively. In such models evaluating the joint association of diabetes distress and depressive symptoms, compared with individuals without diabetes distress or depressive symptoms (DD−/DS−), the HRs for all-cause mortality for the group without diabetes distress but with depressive symptoms (DD−/DS+), with diabetes distress but without depressive symptoms (DD+/DS−), and with diabetes distress and depressive symptoms (DD+/DS+) were 1.34 (95% CI 0.99, 1.86; p = 0.056), 1.96 (95% CI 1.10, 3.50; p = 0.023) and 1.71 (95% CI 1.06, 2.77; p = 0.029), respectively. We did not observe a significant interaction between diabetes distress and depressive symptoms with all-cause mortality risk (p = 0.2636). In the stratified analysis by sex, a significant joint association of diabetes distress and depressive symptoms with the risk of all-cause mortality was observed only in men. Diabetes distress and depressive symptoms were independently associated with all-cause mortality risk in male participants with type 2 diabetes, but we did not observe a significant interaction between diabetes distress and depressive symptoms in relation to all-cause mortality. Graphical abstract