Objective: To investigate the reported association between low serum cholesterol concentration and severe depressive symptoms in an elderly population.
Design: Cross sectional analysis of pooled data from three communities of the established populations for epidemiologic studies of the elderly. Participants who completed their interview, including the Centers for Epidemiologic Studies' depression scale and consented to measurement of their cholesterol concentration were included in the study.
Subjects: 3939 men and women aged > or = 71.
Methods: chi 2 analysis, t tests, and multivariate regression analysis of the association between low cholesterol concentration and severe depressive symptoms. All analyses were stratified by sex, and multivariate analyses were adjusted for age, self reported health, physical function, number of drugs used, and weight loss.
Main outcome measure: Score of depressive symptoms on the Centers for Epidemiologic Studies' depression scale.
Results: Depressive symptoms, cholesterol concentration, weight, and use of drugs were all associated with age in men and women. The relative odds of severe depressive symptoms (score > or = 16) for those with low cholesterol concentrations (< 4.14 mmol/l) were 1.9 (95% confidence interval, 1.1 to 3.3) for the older group of men and 1.8 (1.1 to 2.9) for the older group of women. This association was also observed when depressive symptoms were analysed as a continuous rather than a categorical variable. In multivariate models that adjusted for age, self reported health, physical function, number of drugs used, and weight loss, the association was substantially weakened.
Conclusions: After several factors relating to health had been controlled for, no significant association between low cholesterol concentration and severe depressive symptoms was found.