Association of total bilirubin with depression risk in adults with diabetes: A cross-sectional study.

Abstract

Individuals with diabetes mellitus are more likely to experience depression, although most patients remain undiagnosed. The relation between total bilirubin and depression has been increasingly discussed, but limited studies have examined the association of total bilirubin with depression risk in adults with diabetes, which warrants attention. To investigate the association between total bilirubin levels and the risk of depression in adults with diabetes. The study included adults with diabetes from the National Health and Nutrition Examination Survey 2007-2018. Depression was determined using the Patient Health Questionnaire-9. Multivariable logistic regression, propensity score-matched analysis and restricted cubic spline models were utilized to investigate the association between total bilirubin levels and depression risk in adults with diabetes. The study included 4758 adults with diabetes, of whom 602 (12.7%) were diagnosed with depression. After adjusting for covariates, we found that diabetic adults with lower total bilirubin levels had a higher risk of depression (OR = 1.230, 95%CI: 1.006-1.503, P = 0.043). This association was further confirmed after propensity score matching (OR = 1.303, 95%CI: 1.034-1.641, P = 0.025). Subgroup analyses showed no significant dependence of age, body mass index, sex, race or hypertension on this association. Restricted cubic spline models displayed an inverted U-shaped association of total bilirubin levels with depression risk within the lower range of total bilirubin levels. The depression risk heightened with the increasing levels of total bilirubin, reaching the highest risk at 6.81 μmol/L and decreasing thereafter. In adults with diabetes, those with lower levels of total bilirubin were more likely to have depressive symptoms. Serum total bilirubin levels may be used as an additional indicator to assess depression risk in adults with diabetes.