Analysis of Trends of Sleep-Related Breathing Disorders in Patients with Systemic Essential Hypertension

Abstract

Background: Studies have revealed a strong link between sleep-related breathing disorders and essential hypertension. However, the trends of sleep-disordered breathing in hypertensive patients have not been analyzed frequently. Methods: In this prospective, single-center and observational study, random patients with systemic essential hypertension, who were visiting GSVM Medical College, Kanpur, India between December 2012 and July 2014, were selected. After obtaining informed consent, patients were analyzed for symptoms of sleep-disordered breathing and Epworth Sleepiness Scale. Subsequently, all patients underwent overnight polysomnography to estimate the events of apnea and hypopnea. Observed data were compared between stage I and stage II hypertensive patients. Results: A total of 51 patients (age: 45.7 ± 13.43 years), comprising 36 stage I hypertensives and 15 stage II hypertensives, were enrolled in the study. About 47% of these patients displayed no symptoms of sleep-disordered breathing. Compared to stage I hypertensives, higher percentage of stage II hypertensives reported excessive day time sleepiness. Sleep latency time and sleep architecture were comparable between stage I and stage II hypertensives. Stage II hypertensives displayed shorter total sleep time and higher snore time than stage I hyper-tensives. Apnea Hypopnea Index (AHI) values increased with the severity of hypertension. Nocturnal oxygen desaturation was present in 25.0% and 53.3% of stage I and II hypertensives respectively. Mean lowest oxygen saturation was lower and the mean C-reactive protein levels were higher in stage II hypertensives as compared to stage I hypertensives. The mean C-reactive protein levels increased with increasing AHI scores, while the mean lowest oxygen saturation decreased with increasing AHI scores. Conclusion: Almost half of the hypertensives patients reported no symptoms of sleep-disordered breathing. Sleep-disordered breathing was more common and was more severe in majority of patients with stage II hypertension as compared to that in patients with stage I hypertension.