Objective but Not Subjective Short Sleep Duration Associated with Increased Risk for Hypertension in Individuals with Insomnia

Abstract

Study objectives: To examine the relationship between hypertension prevalence in individuals with insomnia who have short total sleep duration < 6 h or sleep duration ≥ 6 h, using both objective and subjective measures of total sleep duration.

Methods: Using a cross-sectional, observational design, 255 adult volunteers (n = 165 women; 64.7%) meeting current diagnostic criteria for insomnia disorder (MAge = 46.2 y, SDAge = 13.7 y) participated in this study at two large university medical centers. Two nights of polysomnography, 2 w of sleep diaries, questionnaires focused on sleep, medical, psychological, and health history, including presence/absence of hypertension were collected. Logistic regressions assessed the odds ratios of hypertension among persons with insomnia with short sleep duration < 6 h compared to persons with insomnia with a sleep duration ≥ 6 h, measured both objectively and subjectively.

Results: Consistent with previous studies using objective total sleep duration, individuals with insomnia and short sleep duration < 6 h were associated with a 3.59 increased risk of reporting hypertension as a current medical problem as compared to individuals with insomnia with sleep duration ≥ 6 h. Increased risk for hypertension was independent of major confounding factors frequently associated with insomnia or hypertension. No significant risk was observed using subjectively determined total sleep time groups. Receiver operating characteristic curve analysis found that the best balance of sensitivity and specificity using subjective total sleep time was at a 6-h cutoff, but the area under the receiver operating characteristic curve showed low accuracy and did not have good discriminant value.

Conclusions: Objectively measured short sleep duration increased the odds of reporting hypertension more than threefold after adjusting for potential confounders; this relationship was not significant for subjectively measured sleep duration. This research supports emerging evidence that insomnia with objective short sleep duration is associated with an increased risk of comorbid hypertension.

Keywords: hypertension; insomnia; polysomnography; prevalence; short sleep.

Figure 1

Receiver operating characteristic curve for detecting hyper-tension using average total sleep time derived from a 2-w sleep diary. Diagonal segments are produced by ties.

Figure 2

Sensitivity and specificity of detecting hypertension by average total sleep time derived from a 2-w sleep diary.