Abstract
BACKGROUND: To examine the association between sleep-disordered breathing (SDB) and 24-hour blood pressure (BP) pattern among community-dwelling older adults. METHODS: A convenience sample of 70 community-dwelling older adults, recruited from senior housing, community centers, and learning centers, were admitted to General Clinical Research Center, Emory University Hospital, Atlanta, Ga. Information regarding demographic and clinical history was obtained using questionnaires. Twenty-four-hour BP monitoring in supine position was performed using Spacelabs model 20207. Breathing during sleep was monitored with the use of a modified sleep recording system (Embletta, PDS), which monitors nasal and oral airflow, chest and abdominal movements, and pulse oximetry. Night time-daytime (night-day) BP ratio (average night-time BP divided by daytime BP) was calculated both for systolic and diastolic BPs. RESULTS: Sixty-nine participants, mean age 74.9 +/- 6.4 years (41 [57%] women), completed the study. The mean apnea-hypopnea index (AHI) was 13 +/- 13 per hour of sleep, and 20 participants (29%) had AHI > or =15 per hour of sleep, indicating moderate to severe SDB. Moderate to severe SDB (AHI > or =15 per hour of sleep) was significantly associated with nocturnal hypertension, whereas there was no statistically significant difference in wake-time BP between those with and without moderate to severe SDB. Stepwise multiple regressions showed that AHI independently predicted increased night-day systolic and night-day diastolic BP ratio, even after controlling for nocturia frequency. CONCLUSIONS: The results indicate increased BP load associated with increased AHI in this group of older adults. This increased BP load may contribute to increased hypertension-related morbidity and disease burden.