The influence of hypertension on daytime sleepiness in obstructive sleep apnea.

Daytime sleepiness is a common symptom among hypertensive patients. The aim of this study was to determine subjective sleepiness assessed by Epworth Sleepiness Scale (ESS) and to asses sleep architecture in 304 patients with arterial hypertension. All patients underwent a standardized diagnostic overnight, polysomnography. The control group consisted of 67 normotensives. The hypertensive patients had a decreased sleep efficiency, mean and minimum oxygen saturation levels, and increased apnea/hypopnea index and oxygen desaturation index compared with normotensive patients. The lower ratio of N3 sleep, higher of N2 sleep, and decreased sleep efficiency was observed in hypertensives without obstructive sleep apnea (OSA). In the moderate to severe OSA groups, the total ESS score was significantly lower in hypertensives compared with normotensives. The ESS scores decreased with age in hypertensives, but not in normotensives. The study showed that ESS total score is lower in hypertensives than in normotensives with OSA, making the OSA more difficult to suspect. Thus, the low ESS score in hypertensives should not discourage further evaluation.