Shorter sleep duration was associated with increased carotid artery wall thickening (intima-media thickness, IMT) among men, but not women.

In a national study of 617 black and white middle-aged people (37-52 years; 58% female) researchers calculated IMT from the average of 20 measurements of the average common carotid, bulb, and internal carotid IMT, assessed using high-resolution B-mode ultrasound. They used wrist monitors to measure sleep duration.

The average IMT was 0.68 mm for women and 0.74 mm for men. Men slept less than women (5.7 hours vs 6.3 hours). After adjusting for other factors, the researchers found that 1 hour of longer sleep duration was associated with 0.021 mm lesser IMT among men, and 0.002 mm lesser IMT among women.

IMT is a marker for cardiovascular disease. These findings, presented at the American Heart Association’s [removed]Scientific Sessions 2010[/removed] in Chicago, provide novel evidence of potential underlying biological mechanisms, and suggest that sleep duration may be an important risk factor associated with carotid IMT in men.