Insomnia and the risk of hypertension: A meta-analysis of prospective cohort studies

The relationship between insomnia and hypertension remains inconclusive. Thus, we conducted a meta-analysis of prospective cohort studies to evaluate the association between insomnia and the risk of hypertension. Relevant prospective cohort studies were searched from PubMed, Embase, and Web of Science from their inception to October 2019. A random-effects model was used to calculate the pooled relative risk (RR) with 95% confidence interval (CI). A total of fourteen prospective cohort studies involving 395,641 participants were included in this study. The pooled RR of insomnia on hypertension was 1.21 (95%CI: 1.10-1.33). An increased risk of hypertension was observed in participants with difficulty maintaining sleep (RR = 1.27; 95%CI: 1.04-1.55) and early morning awakening (RR = 1.14; 95%CI: 1.08-1.20), but was not statistically significant in participants with difficulty falling asleep (RR = 1.14; 95%CI: 0.95-1.37). In addition, the results were statistically significant in the European population (RR = 1.08, 95%CI: 1.02-1.14), but not significant in Asian and American populations (RR = 1.54, 95%CI: 0.98-2.40; RR = 1.21, 95%CI: 0.89-1.65). The study findings indicate that insomnia is associated with a significantly increased risk of hypertension. This may have substantial implications for the prevention of hypertension in individuals with insomnia symptoms.