Many studies have shown a U-shaped association of sleep duration with mortality; however, this association is difficult to interpret owing to possible reverse causation, residual confounding, and measurement issues. We used data from the Women's Health Initiative to examine the associations of sleep duration, insomnia, and use of sleep aids with death from cardiovascular disease (CVD), cancer, "other" causes, and all causes combined.
Cox proportional hazards models were used in the analysis of baseline data and in time-dependent analyses of repeated measures to estimate associations of sleep-related factors with mortality. Among 158,203 women with information regarding sleep, 30,400 total deaths, 8857 CVD deaths, 9284 cancer deaths, and 11,928 other deaths were ascertained over a median of 17.8 years.
In both baseline and time-dependent analyses, both short (≤5 h) and long sleep (≥9 h) durations were associated with increased risk of total, CVD, and "other" deaths, but not with cancer deaths. Insomnia showed no association with mortality, whereas use of sleep medications was associated with an increased mortality risk.
While our findings showed a small but robust association of sleep duration with mortality in postmenopausal women, studies including objective measurements of sleep quality and efficiency are needed to clarify these associations.
Sleep medicine. 2018 Jun 02 [Epub ahead of print]
Geoffrey C Kabat, Xiaonan Xue, Victor Kamensky, Oleg Zaslavsky, Katie L Stone, Karen C Johnson, Sylvia Wassertheil-Smoller, Aladdin H Shadyab, Juhua Luo, Lauren Hale, Lihong Qi, Jane A Cauley, Robert L Brunner, JoAnn E Manson, Thomas E Rohan
Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA., Department of Biobehavioral Nursing and Health Informatics, School of Nursing, University of Washington, Seattle, WA, USA., Department of Epidemiology and Biostatistics, School of Medicine, University of California San Francisco, San Francisco, CA, USA., Department of Preventive Medicine, University of Tennessee, Memphis, TN, USA., Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA., Department of Epidemiology and Biostatistics, School of Public Health, University of Indiana, Bloomington, IN, USA., Department of Family, Population and Preventive Medicine, School of Medicine, Stony Brook University, Stony Brook, NY, USA., Department of Public Health Sciences, School of Medicine, University of California Davis, Davis, CA, USA., Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA., Department of Family and Community Medicine, University of Nevada School of Medicine, Reno, NV, USA., Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA., Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA. Electronic address: .