Sleep duration is associated with dyslipidemia in patients with bipolar disorder in clinical remission.

BACKGROUND: The pathways to increased cardiovascular risk in bipolar disorder include health behaviors, psychosocial stress and long-term medication exposure. However, the evidence that the association between cardiovascular risk factors and bipolar disorder remains significant after controlling for these co-factors suggests that additional important risk factors have yet to be identified. Our hypothesis is that disturbances in the sleep-wake cycle are an important and under-recognized pathway through which affective disorders lead to increased cardiovascular risk.
METHODS: In patients with bipolar disorder type 1 in clinical remission, we: 1) explored whether sleep disturbance predicted the endorsement of NCEP ATP-III criteria for dyslipidemia, independent of other lifestyle factors and 2) tested the association between low HDL (NCEP-ATP III) and sleep duration measured with actigraphy over an eight-day period.
RESULTS: Median sleep duration is significantly associated with low HDL. The risk of having low HDL increases by 1.23 with every 30 minutes of reduced sleep time. LIMITATIONS: Since sleep patterns in patients with bipolar disorder are variable and irregular, it is possible that other sleep characteristics, not present during the span of our study, or the variability itself may be what drives the increased cardiovascular risk.
CONCLUSIONS: Sleep characteristics of patients with bipolar disorder in clinical remission are associated with cardiovascular risk. More specifically, sleep duration was associated with low HDL. Clinicians should pay special attention to sleep hygiene in treating individuals with bipolar disorder, even when they are in clinical remission.