Low high-density lipoprotein (HDL) cholesterol linked to abnormal sleep

HDL Forum Editor Professor John Chapman notes interesting data from the Nurses’ Health Study which support an association between low high-density lipoprotein (HDL) cholesterol and abnormalities in sleep habits. The analysis was reported in Diabetes Care.

Williams CJ, Hu FB, Patel SR et al. Sleep duration and snoring in relation to biomarkers of cardiovascular disease risk among women with type 2 diabetes. Diabetes Care 2007; 30:1233-40.

In this paper, the researchers reported data from a cohort of 935 women in the Nurses’ Health Study aged 43-69 years with type 2 diabetes and no history of cardiovascular disease (in 1990). Data on sleep duration and snoring frequency were obtained by mailed questionnaire. Biomarkers of cardiovascular disease were measured in blood samples taken between 1989 and 1990.

HDL cholesterol levels were significantly lower in normotensive women reporting either short or long duration of sleep (p=0.02). In multivariate-adjusted analyses, low HDL cholesterol was also inversely associated with more frequent snoring (p=0.03).

These provocative data further consolidate the hypothesis that frequent snoring appears to be associated with mild ischaemia in certain organs and tissues, including cardiac muscle and brain. Interestingly, the potential association of low HDL cholesterol, abnormal sleep habits and cardiovascular risk may result, at least in part, from the attenuated vasculoprotective actions of subnormal numbers of HDL particles. Indeed HDL are known to increase the bioavailability of nitric oxide (NO) and to protect endothelial cells from apoptosis induced by oxidative stress. Further basic and clinical research is a priority in this area.