Longitudinal associations between insomnia symptoms and all-cause mortality among middle-aged and older adults: a population-based cohort study

Authors

Asos Mahmood, Division of Health Systems Management and Policy, the University of Memphis School of Public Health, Memphis, TN, USA.
Meredith Ray, Division of Epidemiology, Biostatistics, and Environmental Health, the University of Memphis School of Public Health, Memphis, TN, USA.
Kenneth D. Ward, Division of Social and Behavioral Sciences, the University of Memphis School of Public Health, Memphis, TN, USA.
Aram Dobalian, Division of Health Systems Management and Policy, the University of Memphis School of Public Health, Memphis, TN, USA.
SangNam Ahn, Division of Health Systems Management and Policy, the University of Memphis School of Public Health, Memphis, TN, USA.Follow

Abstract

To date, there is no scientific consensus on whether insomnia symptoms increase mortality risk. We investigated longitudinal associations between time-varying insomnia symptoms (difficulty initiating sleep, difficulty maintaining sleep, early-morning awakening, and nonrestorative sleep) and all-cause mortality among middle-aged and older adults during 14 years of follow-up. Data were obtained from 2004 through 2018 survey waves of the Health and Retirement Study in the United States for a population-representative sample of 15 511 respondents who were ≥50 years old in 2004. Respondents were interviewed biennially and followed through the end of the 2018 survey wave for the outcome. Marginal structural discrete-time survival analyses were employed to account for time-varying confounding and selection bias. Of the 15 511 cohort respondents (mean [±SD] age at baseline, 63.7 [±10.2] years; 56.0% females), 5878 (31.9%) died during follow-up. At baseline (2004), 41.6% reported experiencing at least one insomnia symptom. Respondents who experienced one (HR = 1.11; 95% CI: 1.03-1.20), two (HR = 1.12; 95% CI: 1.01-1.23), three (HR = 1.15; 95% CI: 1.05-1.27), or four (HR = 1.32; 95% CI: 1.12-1.56) insomnia symptoms had on average a higher hazard of all-cause mortality, compared to those who were symptom-free. For each insomnia symptom, respondents who experienced difficulty initiating sleep (HR = 1.12; 95% CI: 1.02-1.22), early-morning awakening (HR = 1.09; 95% CI: 1.01-1.18), and nonrestorative sleep (HR = 1.17; 95% CI: 1.09-1.26), had a higher hazard of all-cause mortality compared to those not experiencing the symptom. The findings demonstrate significant associations between insomnia symptoms and all-cause mortality, both on a cumulative scale and independently, except for difficulty maintaining sleep. Further research should investigate the underlying mechanisms linking insomnia symptoms and mortality.

Publication Title

Sleep

Recommended Citation

Mahmood, A., Ray, M., Ward, K. D., Dobalian, A., & Ahn, S. (2022). Longitudinal associations between insomnia symptoms and all-cause mortality among middle-aged and older adults: a population-based cohort study. Sleep, 45 (6) https://doi.org/10.1093/sleep/zsac019