Low cholesterol levels linked to manic symptomatology in BD
MedWire News: Individuals with bipolar disorder (BD) who have low cholesterol levels may be predisposed to a greater burden of manic symptomatology than those with normal or high cholesterol levels, show study findings.
This finding “supports prior case-control and cross-sectional findings,” say Jess Fiedorowicz (University of Iowa, Iowa City, USA) and colleagues.
Using data from the Collaborative Depression Study, a prospective cohort study, the researchers identified 131 individuals with a major affective disorder who had fasting total cholesterol measured at study enrolment and were followed-up for a mean of 15.7 years.
The 66 patients with unipolar depression spent 37.6% of weeks with clinically significant depressive symptoms, on average, while those with BD spent 30.9% and 4.5% of weeks with depressive and manic symptoms, respectively.
Regression analysis showed no relationship between cholesterol levels and depressive symptomatology after controlling for age, gender, and use of mood-stabilizing medication.
There was no significant inverse, linear association with depressive symptomatology among bipolar patients either, but in this group lower cholesterol predicted a higher proportion of follow-up weeks spent with manic symptoms.
The researchers note that the relationship between cholesterol and subsequent manic symptom burden was not confounded by hypertension, diabetes mellitus, thyroid disease, or weight loss over 10 lb during the present episode.
Fiedorowicz et al say that cholesterol may influence affect through a variety of mechanisms, such as its impact on modulatory serotonergic pathways.
They therefore suggest that inconsistencies in published findings may be a result of “a complex relationship yet to be elucidated, consistent with diversity of proposed physiological mediators.”
Writing in the journal Psychiatry Research, the team concludes: “The convergence of further clinical research with expansion of scientific knowledge at the basic level will be critical to eventually elucidate a presumably complex relationship between cholesterol and affective symptomatology.”
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By Ingrid Grasmo