Background: The potential mediating effect of cardiovascular diseases (CVDs) (e.g., ischemic heart disease and stroke) on the association between abnormal serum lipids and late-life depressive symptoms has not been investigated.
Purpose: We aimed to examine the associations between serum lipids and elevated depressive symptoms among older Chinese people and to determine the extent to which CVDs mediate their associations.
Method: This cross-sectional study included 1,529 participants (age ≥60 years, 59.2% women) in the Confucius Hometown Aging Project. In June 2010-July 2011, data were collected through an interview, clinical examinations, and laboratory tests. Abnormal serum lipids were defined according to international criteria and use of hypolipidemic drugs. Presence of elevated depressive symptoms was defined as the 15-item Geriatric Depression Scale score ≥5. Data were analyzed with logistic and mediation models controlling for potential confounders.
Results: The prevalence of depressive symptoms was 20.3%. Depressive symptomatology was significantly associated with high total cholesterol, high triglycerides, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C), and dyslipidemia (p < 0.05). The mediating effects on the associations of serum lipids with depressive symptoms were statistically significant for ischemic heart disease and stroke with the proportion of mediating effects over the total effects ranging 4.7-7.0% and 7.3-12.1%, respectively.
Conclusion: Elevated depressive symptoms are associated with lipid profile characterized by high cholesterol, high triglycerides, low HDL-C, high LDL-C, and dyslipidemia; the associations are partially mediated by ischemic heart disease and stroke. These findings imply that unfavorable lipid profile may be involved in late-life depressive symptoms independent of atherosclerotic disorders.