Objective: Although elevated heart rate and blood pressure might represent biologically plausible links for the association of insomnia symptoms with increased risk of cardiovascular disease (CVD), few large studies have investigated the associations of insomnia symptoms with these factors. Our aim was to investigate the associations of self-reported insomnia symptoms with systolic and diastolic blood pressure and resting heart rate in a large population-based study.
Participants: Self-reported information on insomnia symptoms, including sleep initiation problems, frequent awakening and early awakenings during night, and measurements of resting heart rate and blood pressure were collected from a total of 50,806 men and women who participated in the third wave of the Nord-Trøndelag Health Study (HUNT-3) in 2006-2008.
Methods: In multivariable analyses, we adjusted for sociodemographic factors, lifestyle factors, established CVD risk factors, and snoring or breathing pauses.
Results: Compared to participants reporting none of the insomnia symptoms, those having all three insomnia symptoms several times a week had lower diastolic blood pressure (-0.80 [95% CI: -1.47 to -0.14] mmHg, p = 0.02), lower systolic blood (-1.69 [95% CI: -2.76 to -0.63) mmHg, p < 0.001), and higher resting heart rate (0.83 [95% CI: 0.11 to 1.55] beats/minute, p = 0.02).
Conclusions: We found a modest positive association of insomnia symptoms with resting heart rate, and a modest inverse association of insomnia with blood pressure. However, the actual differences were small, and likely of less clinical importance. Prospective studies are needed to establish whether the potential link between insomnia and CVD is mediated through changes in heart rate and/or blood pressure.