The mediating role of obesity in the development of depression in individuals with diabetes: A population-based study from NHANES 2005-2014

Objective: Depression is one of the common manifestations of diabetes population, and previous studies have shown that there is a correlation between depression and diabetes. This study was conducted retrospectively through the large National Health and Nutrition Examination Survey (NHANES) to explore the risk of depression in different individuals with diabetes. Methods: We collected data on a total of 33,001 individuals in 5 cycles of NHANES and compared the incidence of depression in the individuals with diabetes, pre -diabetes or without diabetes groups after weighting. A weighted logistic review was used to assess the association between diabetes and depression at different BMI, sex, and age levels. Mediating analysis was used to assess the risk of depression in people with obesity -mediated diabetes. In addition, the non-linear relationship between BMI and depression at different factor levels was evaluated using restricted cubic strips (RCS). Results: Diabetes was significantly associated with depression in obesity, especially for female (OR: 1.45, 95 % CI: 1.20-1.75, P < 0.001) and young (60 years old) (OR: 2.03, 95 % CI: 1.31-3.15, P = 0.002). Mediating analysis showed that obesity explained 28.6 % of the risk of depression in people with diabetes. The RCS curve further confirms the non-linear relationship between BMI and depression risk, that is, regardless of age, sex, and diabetes, the risk of depression increases with BMI. At the same BMI level, diabetes, youth (age < 60) and women have a higher risk of depression. Conclusions: There is a significant correlation between diabetes and depression, and obesity as a mediating variable mediates the correlation between diabetes and depression. Especially in obese, young (age < 60) and women, the phenomenon is more pronounced.