Fragmented Sleep and the Prevalence of Hypertension in Middle-Aged and Older Individuals

Abstract

Objective: We aimed to investigate the association between fragmented sleep and the prevalence of hypertension in middle-aged and older individuals.

Methods: This study included 5804 participants with an average age of 63.1±11.2 years from the Sleep Heart Health Study. Fragmented sleep parameters including arousal index in total sleep (ArI-Total), rapid eye movement sleep (ArI-REM), non-rapid eye movement sleep (ArI-NREM), fragmented sleep index (SFI), sleep efficiency (SE) and wake after sleep onset (WASO) were monitored using polysomnography. The information on hypertension, defined as systolic blood pressure (SBP) ≥140 mmHg and/or diastolic blood pressure (DBP) ≥90 mmHg or under antihypertensive treatment, was collected at baseline. We conducted multivariable logistic regression to explore the cross-sectional association between fragmented sleep and the prevalence of hypertension.

Results: After adjusting for potential confounders, fragmented sleep parameters (per 5-unit change) including SE (odds ratio [OR] 0.904; 95% confidence interval [CI] 0.877-0.932; P < 0.001), WASO (OR 1.019; 95% CI 1.012-1.027; P < 0.001), ArI-Total (OR, 1.036; 95% CI, 1.005-1.068; P = 0.024), and ArI-NREM (OR 1.032; 95% CI 1.004-1.062; P = 0.027) were significantly associated with the prevalence of hypertension. In addition, ArI-Total, ArI-NREM, and ArI-REM were positively correlated with both systolic blood pressure and diastolic blood pressure.

Conclusion: We found a high prevalence of hypertension among middle-aged and older individuals with fragmented sleep. The causal association between fragmented sleep and hypertension warrants further investigation.

Keywords: Sleep Heart Health Study; blood pressure; cross-sectional study; fragmented sleep; polysomnography.

Figure 1

The distribution of prevalent hypertension in different fragmented sleep quartiles. (A) ArI-Total (quartile 1: <12.0 events/h, quartile 2: 12.0–16.7 events/h, quartile 3: 16.8–23.5 events/h, and quartile 4: ≥23.6 events/h); (B) ArI-NREM (quartile 1: <12.1 events/h, quartile 2: 12.1–17.2 events/h, quartile 3: 17.3–24.8 events/h, and quartile 4: ≥24.9 events/h); (C) ArI-REM (quartile 1: <7.8 events/h, quartile 2: 7.8–12.9 events/h, quartile 3: 13.0–20.2 events/h, and quartile 4: ≥20.3 events/h); (D) SFI (quartile 1: <6.7 events/h, quartile 2: 6.7–8.5 events/h, quartile 3: 8.6–10.6 events/h, and quartile 4: ≥10.7 events/h); (E) SE (quartile 1: <77.7%, quartile 2: 77.7%-85.0%, quartile 3: 85.1%-90.4%, and quartile 4: ≥90.5%); (F) WASO (quartile 1: <29.6min; quartile 2: 29.6–49.4 min; quartile 3: 49.5–81.9 min; quartile 4: >82.0min).