Obstructive sleep apnea comorbid with insomnia symptoms and objective short sleep duration is associated with...

Co-morbid insomnia and obstructive sleep apnea (COMISA) poses greater cardiovascular risks than either condition alone. We investigated whether COMISA associated with insomnia with short sleep duration (ISSD) phenotype is associated with an increased risk of incident hypertension in a large random general population sample.

From the 1741 participants of the Penn State Adult Cohort, 1395 were followed-up after 7.5 years and 786 did not have hypertension at baseline. Hypertension was determined by a self-report of receiving treatment for high blood pressure. Insomnia symptoms were defined as either a complaint of chronic insomnia lasting ≥ 1 year or a complaint of difficulty falling asleep, staying asleep, nonrestorative sleep, or early morning awakening. All subjects underwent 8-h in-laboratory polysomnography. Obstructive sleep apnea was defined as an obstructive apnea/hypopnea index ≥ 5 event/h. Objective short sleep duration was defined as < 6 h sleep.

The mean age of the study population was 47.5 ± 12.7 years and 51.3% were women. Compared to good sleepers, the highest risk of incident hypertension was in the COMISA with ISSD phenotype (OR = 4.25, 95%CI = 1.52-11.90), followed by OSA-alone (OR = 3.31, 95%CI = 1.85-5.92) and ISSD (OR = 2.27, 95%CI = 1.29-4). The insomnia with normal sleep duration phenotype alone or with OSA (COMISA) was not significantly associated with incident hypertension.

The additive effect of COMISA on hypertension risk is associated with the ISSD phenotype, the most severe biological phenotype of insomnia. Obtaining objective sleep duration in addition to apnea/hypopnea and/or oxygen saturation indices may lead to a more accurate diagnosis and treatment of COMISA.