The association between insomnia and cardiovascular diseases.

Insomnia, the most common sleep complaint in the general population, is defined by difficulty initiating or maintaining sleep, or nonrestorative sleep, accompanied by some form of daytime impairment. In the current review, we present an overview of recent studies on the association between insomnia and cardiovascular disease. It can be concluded that there is growing evidence for the hypothesis that insomnia is associated with an increased risk for cardiovascular disease independently of classic coronary risk factors. Furthermore, insomnia is likely to be associated with hypertension and elevated resting heart rate, both known to lead to cardiovascular disease. However, the existing evidence is not totally consistent and most findings have not been replicated unequivocally. The major limitations of the cited studies include the failure to use state-of-the-art criteria for insomnia diagnosis, the failure to control for depression, and the use of hypnotic medication and sleep apnea as potential confounders. However, the results suggest that insomnia is associated with an increased risk for cardiovascular disease mediated by hypertension or elevated resting heart rate. Consequently, more effort should be dedicated to cope with the high prevalence of insomnia in the general population.