Abstract 13446: Rapid Eye Movement Sleep is Associated With Ambulatory Blood Pressure in Hypertension

Introduction: Growing evidence suggests that aberrant sleep architecture is linked to heightened risk of cardiovascular disease independently of sleep apnea. Rapid Eye Movement (REM) sleep is characterized by increased sympathetic activity and blood pressure (BP) compared to non-REM sleep stages. However, whether REM sleep is associated with BP across the 24 hours has not been investigated. Hypothesis: We hypothesized that increased REM sleep would be associated with higher ambulatory BP. Methods: We recruited 137 individuals (58% men, aged 39±14 years, office systolic/diastolic BP [SBP/DBP] 125±14/77±11 mmHg) who completed overnight polysomnography followed by 24-h ambulatory BP monitoring. Sleep was scored according to standard criteria. 24-h, daytime, and nighttime averages were calculated for SBP, DBP and heart rate. REM sleep duration was computed as percentage of total sleep time and used to group participants into tertiles as follows: T1 (REM% ≤18.8), T2 (REM% 18.9-24), and T3 (REM% ≥24.1). Results: Sex ratio, body mass index, and apnea-hypopnea index were similar across REM tertiles, but age increased with increasing tertiles (p=0.029). 24-h SBP (T1 vs T2 vs T3: 121±12 vs 117±7 vs 124±12 mmHg, p=0.015) and DBP (72±7 vs 70±6 vs 76±8 mmHg, p<0.001) differed across REM sleep tertiles, with significantly higher values in those in the highest tertile. Results were consistent when considering daytime SBP (T1 vs T2 vs T3: 126±12 vs 122±8 vs 132±14 mmHg, p<0.001) and DBP (77±7 vs 76±6 vs 83±9 mmHg, p<0.001), and nighttime DBP (65±9 vs 61±7 vs 65±8 mmHg, p=0.047). No differences were noted on nighttime SBP or any heart rate measures. A significant interaction was found between hypertension status and REM sleep in multiple regression analysis, with the observed associations being significant only among hypertensives (n=69). In those with hypertension, REM sleep duration was associated with 24-h mean BP independently of age, sex, body mass index, apnea-hypopnea index and antihypertensive medications (standardized beta 0.22, p=0.041). Conclusions: Longer REM sleep duration is independently associated with elevated ambulatory BP in individuals with hypertension. REM sleep may be a novel cardiovascular risk indicator in this population.