November 4, 2014
Science Daily/Armed Forces Health Surveillance Center (AFHSC)
Service members diagnosed with chronic insomnia had a two times higher risk of developing hypertension and type II diabetes than military personnel who had not been diagnosed with the condition, according to a newly released health surveillance report of a study of the associations between these diseases.
Insomnia is a common complaint among service members due to career-related stress factors, such as frequent deployments with demanding military operations, varying work shifts, and the challenges of maintaining relationships with their spouses and families.
"This type of analysis has military relevance because it supports the notion that adequate sleep among our service members is important not only for accident prevention and work performance, but also for additional long-term health benefits," said Air Force Lieutenant Colonel Paul E. Lewis, the author of the study and a preventive medicine resident at the Uniformed Services University of the Health Sciences.
The association of chronic insomnia with hypertension was seen both in service members younger than 30 years of age and in those aged 30 years or older, with adjusted hazard ratios of 2.32 and 1.94, respectively. By gender, chronic insomnia had a stronger association with hypertension in men (adjusted hazard ratio of 2.17) than in women (adjusted hazard ratio of 1.59).
The adjusted hazard ratio was also greater for white, non-Hispanics (ratio of 2.26) than for black, non-Hispanics (ratio of 1.72). Both obese subjects and non-obese subjects had significantly increased risks of hypertension related to insomnia, with adjusted hazard ratios of 2.09 and 1.86, respectively.
Previous studies on this topic have provided conflicting results, with some demonstrating a strong association and others finding minimal to no association. There are several reasons why the findings of this study may not be directly comparable to studies in civilian populations. Military members are generally younger and have less co-morbidity than their civilian counterparts.
This analysis employed a longitudinal study design that allowed for follow-up of individuals over time, whereas many previous study designs did not allow evaluation between an exposure to a risk factor and a subsequent outcome. The average follow-up time was 3.09 years in the insomnia cohort and 3.42 years in the control cohort. These differences in methodology might partially explain the observed increased risks of hypertension and diabetes associated with chronic insomnia in this study but not seen in some other studies.