NEW YORK (Reuters Health) Apr 03 - Short sleep durations over a prolonged period appears to be an important and potentially modifiable risk factor for hypertension, according to a report in the May issue of Hypertension.

"People who sleep for only short durations raise their average 24-hour blood pressure and heart rate," lead author Dr. James E. Gangwisch, from Columbia University in New York, said in a statement. "This may set up the cardiovascular system to operate at an elevated pressure."

Previous reports have linked sleep disorders with cardiovascular disease, but it was unclear if sleep deprivation, in subjects who did not have a sleep disorder, affected the risk of hypertension.

The findings are based on an analysis of data for 4810 subjects, between 32 and 86 years old, who participated in the first National Health and Nutrition Examination Survey. Hypertension was diagnosed in 647 subjects during the follow-up period from 1982 to 1992.

Among the subjects between 32 and 59 years of age, sleeping less than 6 hours per night raised the risk of hypertension by 2.10-fold, the report indicates. Moreover, this association remained significant after adjusting for obesity and diabetes, which were both hypothesized to be partial mediators of the relationship.

Further studies are needed to better understand the mechanisms linking sleep deprivation with high blood pressure, the authors note. "If short sleep duration functions to increase blood pressure, then interventions that increase the amount and quality of sleep could potentially serve as treatments and as primary preventative measures for hypertension."

Hypertension 2006;47.

My suggestion: sleep at least 7-8 hours in a day!