Serum lipid changes following the onset of depressive symptoms in postmenopausal women

A cross-sectional association between depression and serum low-density lipoprotein cholesterol (LDL-c) has been noted in psychiatric literature, raising the question of temporality: does low LDL-c predict depression, does depression lead to changes in LDL-c levels, or is this relationship bidirectional? In a previous longitudinal analysis of postmenopausal women ages 50-79 who participated in the Women's Health Initiative (WHI), we detected an association between low LDL-c and the subsequent onset of depressive symptoms (HR=1.25, 95% CI 1.05-1.49, p=0.01). This current study uses the WHI cohort to explore the question of temporality in the opposite direction, examining the influence of depressive symptoms on subsequent changes in LDL-c levels. This study provides no evidence to suggest an association between depression and subsequent changes in LDL-c level (-2.78mg/dL, 95% CI=-7.49 to 1.92, p=0.25), nor was any association detected for total cholesterol, HDL, or triglyceride changes over time. Further, this study demonstrates that the relationship between depression and serum LDL changes is not mediated by changes in weight, exercise, or energy intake.