Association between remnant cholesterol and depression in middle-aged and older Chinese adults: a population-based cohort study

Background: The focus on remnant cholesterol (RC) has intensified because of its association with various diseases. In this study, we investigated the association between RC and depression in middle-aged and older adults. Methods: The study involved 7,305 participants from the 2015 and 2018 waves of the China Health and Retirement Longitudinal Study. Based on the 10-item Center for Epidemiological Studies Depression Scale (CESD-10), depression was indicated by scores ≥ 12. To assess the correlation between RC levels and depression, a logistic regression model that incorporated restricted cubic spline techniques was used. Results: Of the study population, (mean age: 60.0 ± 9.5 years), 50.3% were female. From 2015 to 2018, the mean CESD-10 score increased from 6.31 ± 3.56 to 7.85 ± 5.23. Following adjustment for confounding factors, individuals in the higher RC level quartile exhibited a higher depression risk (Q3: odds ratio [OR]: 1.75, 95% confidence intervals [CI]: 1.29-2.39; Q4: OR: 2.68, 95% CI: 1.96-3.68, P for trend < 0.001), with a linear correlation between RC levels and depression (P for nonlinearity = 0.108). And the subgroup analysis yielded results consistent with the primary findings. Conclusion: This study revealed that in China, in middle-aged and older individuals, elevated RC levels were associated with a higher depression risk, suggesting RC is a promising target for depression prevention and treatment.