AVOIDING THE SUPINE POSITION DURING SLEEP LOWERS 24 H BLOOD-PRESSURE IN OBSTRUCTIVE SLEEP-APNEA (OSA) PATIENTS

Obstructive sleep apnea (OSA), is a common clinical condition affectin g at least 2-4% of the adult population, Hypertension is found in abou t half of all OSA patients, and about one-third of all patients with e ssential hypertension have OSA. There is growing evidence that success ful treatment of OSA can reduce systemic blood pressure (BP). Body pos ition appears to have an important influence on the incidence and seve rity of these sleep-related breathing disturbances. We have investigat ed the effect of avoiding the supine position during sleep for a 1 mon th period on systemic BP in 13 OSA patients (six hypertensives and sev en normotensives) who by polysomnography (PSG) were found to have thei r sleep-related breathing disturbances mainly in the supine position. BP monitoring was performed by 24-h ambulatory BP measurements before and after a 1 month intervention period. We used a simple, inexpensive method for avoiding the supine posture during sleep, namely the tenni s ball technique. Of the 13 patients, all had a reduction in 24-h mean BP (MBP), The mean 24-h systolic/diastolic (SBPIDBP) fell by 6.4/2.9 mm Hg, the mean awake SBP/DBP fell by 6.6/3.3 mm Hg and the mean sleep ing SBP/DBP fell by 6.5/2.7 mm Hg, respectively, All these reductions were significant (at least P < 0.05) except for the sleeping DBP. The magnitude of the fall in SEP was significantly greater in the hyperten sive than in the normotensive group for the 24 h period and for the aw ake hours. In addition, a significant reduction in BP variability and load were found. Since the majority of OSA patients have supine-relate d breathing abnormalities, and since about a third of all hypertensive patients have OSA, avoiding the supine position during sleep, if conf irmed by future studies, could become a new non-pharmacological form o f treatment for many hypertensive patients.