Insomnia Symptom Frequency and Hypertension Risk: A Population-Based Study

Objective: To determine whether increasing frequency of insomnia symptoms is associated with increasing hypertension risk.

Method: This was a large population-based multiyear cross-sectional study. Participants of the 2005-2008 National Health and Nutrition Examination Surveys responding to sleep quality questions were included (n = 12,643). Self-reported insomnia symptoms (ie, difficulty falling asleep, prolonged nocturnal awakening, or undesired early morning awakening, based on DSM-IV-TR, National Institutes of Health, and American Academy of Sleep Medicine criteria) over the past month with and without self-reported short sleep time (ie, < 6 hours) were categorized as 0, 1-4, 5-15, and 16-30 times in the past month. Outcomes included doctor-diagnosed self-reported hypertension made at any point in the past, self-reported current receipt of antihypertensive medications, and measured systolic and diastolic hypertension.

Results: While significant and increasing unadjusted odds of doctor-diagnosed hypertension and current antihypertensive medication receipt were found among individuals with increasing insomnia symptom frequency, these odds ratios (ORs) were for the most part rendered nonsignificant after controlling for covariates (eg, adjusted ORs and 95% confidence intervals [CIs] of current antihypertensive receipt for insomnia symptoms coupled with short sleep time: 1-4 times in the past month: 1.17, 0.78-1.76; 5-15 times in the past month: 1.60, 1.01-2.53; and 16-30 times in the past month: 1.41, 0.93-2.14). Even before controlling for covariates, there were generally no significant positive associations between objectively measured systolic and diastolic hypertension and insomnia symptoms regardless of symptom frequency (eg, unadjusted ORs and 95% CIs of measured systolic hypertension for insomnia symptoms coupled with short sleep time: 1-4 times in the past month: 0.88, 0.53-1.47; 5-15 times in the past month: 1.16, 0.77-1.77; and 16-30 times in the past month: 1.30, 0.95-1.78).

Conclusions: Insomnia symptoms, regardless of their frequency, are generally not significantly positively associated with hypertension. These results have important implications relating to screening and management of patients with insomnia symptoms.