Shorter sleep linked to lower HDL cholesterol in bipolar patients
MedWire News: Shorter sleep duration is associated with lower high-density lipoprotein (HDL) cholesterol levels in patients with bipolar disorder who are in clinical remission, researchers report.
As patients with the mood disorder are known to be at increased risk for cardiovascular morbidity and mortality "clinicians should pay special attention to sleep hygiene in treating individuals with BD, even when they are in clinical remission," say Isabella Soreca (University of Pittsburgh, Pennsylvania, USA) and team.
The findings come after a study of remitted bipolar I disorder patients who had a Hamilton Depression Rating Scale score of 10 or less and a Young Mania Rating Scale score of 8 or less for at least 2 weeks, and who had not been hospitalized in the previous year.
All of the participants supplied blood samples at study entry and underwent sleep assessments for 1 week.
Dyslipidemia was defined according to National Cholesterol Education Program Adult Treatment Panel (ATP)-III criteria as an HDL cholesterol level of less than 40 mg/dL in men and less than 50 mg/dL in women.
The researchers found that patients with low HDL cholesterol levels (n=39) had a significantly shorter average sleep duration than those without (n=29), at 7.40 versus 8.63 hours.
However, there were no significant differences between the two groups in terms of mood symptom scores, age, nicotine use, and body mass index.
Further analysis showed that shorter sleep duration was significantly associated with an increased risk for low HDL cholesterol levels among the participants. Indeed, logistic regression showed that each 30-minute reduction in average sleep duration was associated with a 1.23-fold increased risk for having low HDL cholesterol levels.
Soreca and team conclude in the Journal of Affective Disorders: "In this study, we show that sleep characteristics of patients with bipolar disorder in clinical remission are associated with cardiovascular risk. More specifically, sleep duration was associated with increased risk of having low HDL according to the ATP III definition.
"Further studies to elucidate mechanisms for sleep-related cardiovascular risk in mood disorder are needed."
By Mark Cowen