Restless Legs Syndrome Sends Nocturnal Blood Pressure Up

MONTRAL, April 10 -- Restless legs syndrome may boost nocturnal blood pressure and exacerbate cardiovascular disease risks, particularly among older patients, investigators here suggested.

Older adults with restless legs syndrome of long duration may be particularly at risk, reported Paola A. Lanfranchi, M.D., M.Sc., of the Hpital du Sacr Coeur de Montral, and colleagues, in the April 10 issue of Neurology.

Blood pressure surges related to periodic leg movements during sleep might affect the cardiovascular system of otherwise healthy patients, they wrote, citing several epidemiologic studies between those with restless legs syndrome and cardiovascular disease.

Although restless legs syndrome has been associated in population-based studies with increased risk for coronary artery disease and hypertension, the mechanisms underlying the increased risk are unknown, the authors wrote.

They enrolled four women and six men with the syndrome into a study assessing both heart rate and blood pressure changes associated with periodic leg movements during sleep, with or without EEG signs of arousal.

The patients, mean age 47.3 + 13.5 years, spent one night in a sleep lab, during which they were monitored with polysomnography and noninvasive beat-to-beat blood pressure monitoring. For each participant, 10 periodic leg movements during sleep with microarousals, and 10 periodic leg movements during sleep without microarousals were given cardiovascular analysis.

Both systolic and diastolic blood pressures were measured within a 25-beat temporal window comprising 10 beats before the onset of each movement, and 15 beats afterward. Blood pressure changes related to periodic leg movements during sleep were with repeated measure using one-way analysis of variance.

Blood pressure changes associated with periodic leg movements during sleep with and without microarousals were compared by paired t-tests, and the authors used Pearson correlation coefficients to assess the relationship between cardiovascular changes and clinical and polysomnographic variables.

They found that blood pressure increased significantly in association with all periodic leg movements during sleep, with an average increase in systolic of 22 mm Hg, and increase in diastolic of 11 mm Hg.

Changes in blood pressure during periodic leg movements during sleep were significantly greater when they were also associated with microarousals than when there were no microarousals (P