Insomnia symptoms and increased risk of all-cause mortality by age and sex.

Abstract

Prior research suggests that insomnia may increase the risk of death. However, the potential influence of age and sex is unclear. This study aimed to investigate the association of insomnia symptoms with all-cause mortality by age and sex. This prospective cohort was drawn from the Health and Retirement Study, a survey of Americans older than 50 years and their spouses of any age from 2002 to 2018. Insomnia symptom scores were based on difficulties initiating sleep, difficulty maintaining sleep, waking up too early, and restorative sleep. Cox proportional hazards regression models were employed to investigate the association between insomnia symptoms and all-cause mortality stratified by age and sex. A total of 33004 participants were included with a mean age of 61.7 years and 56.8% females. Over a mean follow-up of 8.4 years, 8935 (27.1%) deaths were recorded. After adjusting for confounding, males with insomnia symptom scores ranging from 5 to 8 had a 71% increased risk of death (HR=1.71, 95% CI: 1.27, 2.30) compared to their counterparts without insomnia symptoms. Similarly, males aged ≥60, and females aged <60 with insomnia symptoms ranging from 5-8 had an increased risk of death compared to their counterparts without insomnia symptoms (HR=1.15, 95%: 1.02, 1.31, and HR=1.38, 95% CI: 1.00, 1.90, respectively). However, there was no increased risk of death for females aged ≥60 (HR=0.94, 95% CI: 0.84, 1.06). These findings suggest that insomnia symptoms may serve as predictors of low life expectancy.