Traditional and nontraditional cardiovascular risk factors in comorbid insomnia and sleep apnea

Abstract

Objectives: Insomnia and sleep apnea frequently co-occur and are independently associated with an increased risk of cardiovascular disease, but little is known about cardiovascular disease risk among individuals with comorbid insomnia and sleep apnea. The current study examined traditional risk factors and a physiologic biomarker of cardiovascular risk in comorbid insomnia and sleep apnea.

Design: Community-based participatory research study.

Participants: The sample comprised 795 participants without preexisting cardiovascular disease from the Heart Strategies Concentrating On Risk Evaluation (Heart SCORE) study.

Measurements and results: Participants were assessed for symptoms of insomnia and sleep apnea risk, as well as for presence of obesity, smoking, a sedentary lifestyle, hypertension, dyslipidemia, and diabetes. Baseline resting brachial artery diameter was measured by B-mode ultrasonography. A total of 138 participants (17.4%) met criteria for insomnia syndrome alone, 179 (22.5%) were at high risk for sleep apnea alone, 95 (11.9%) reported both insomnia syndrome and high sleep apnea risk, and 383 (48.2%) reported having neither insomnia nor sleep apnea symptoms Both high sleep apnea risk alone and comorbid insomnia and high sleep apnea risk groups had greater frequencies of obesity, sedentary lifestyle, hypertension, and three or more traditional cardiovascular risk factors and significantly larger brachial artery diameters than the insomnia alone group and those without insomnia or sleep apnea symptoms. No differences in traditional cardiovascular risk factors or brachial artery diameter were found between the high sleep apnea risk and comorbid groups.

Conclusions: These findings suggest that sleep apnea is a major contributor to cardiovascular risk and co-occurring insomnia does not appear to add to this risk.

Keywords: Cardiovascular diseases; hypertension; insomnia; risk factors; sleep apnea.

Figure 1

Frequencies of traditional cardiovascular risk factors among individuals with comorbid insomnia syndrome and high sleep apnea risk, insomnia syndrome alone, high sleep apnea risk alone, and controls. *Bonferroni-corrected P < 0.002 versus controls (reference group). Multivariate logistic regressions were adjusted for age, sex, and race. BMI, body mass index; CVD, cardiovascular disease.