Many types of comorbidities are associated with clinically diagnosed insomnia in United States military service members

Abstract: OBJECTIVES: This cross-sectional investigation examined associations between clinically diagnosed insomnia (CDI) and comorbid conditions in United States military service members (SMs). METHODS: A stratified random sample of SMs completed an on-line questionnaire assessing their demographic and lifestyle characteristics. Diagnosed medical conditions for a six-month period prior to questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 18 general (largely systemic) and 30 specific clinically diagnosed medical categories (CDMCs). CDMC prevalence odds was compared among those with (n = 771) and without (n = 25,909) CDI. RESULTS: After adjustments for potentially confounding demographic and lifestyle characteristics, CDI was associated with higher odds of a diagnosis in 17 of the general CDMCs and 26 of the specific CDMCs. The five general CDMCs with the largest differences between those with and without CDI were mental/behavioral diseases (odds ratio [OR] = 7.68, 95% confidence interval [95%CI] = 6.54-9.01), signs/symptoms/abnormal labs (OR = 4.99, 95%CI = 4.19-5.93), diseases of the musculoskeletal system (OR = 4.43, 95%CI = 3.72-5.28), endocrine/nutritional/metabolic diseases (OR = 2.97, 95%CI = 2.47-3.58), and diseases of the digestive system (OR = 2.68, 95%CI = 2.18-3.28). The five specific CDMCs with the highest adjusted odds among those with and without CDI were sleep-related movement disorder (OR = 14.68, 95%CI = 9.26-23.26), fibromyalgia (OR = 14.14, 95%CI = 5.74-34.80), post-traumatic stress disorder (OR = 12.94, 95%CI = 10.09-16.59), anxiety (OR = 9.40, 95%CI = 7.71-11.46), and traumatic brain injury (OR = 8.52, 95%CI = 5.93-12.24). Prevalence of CDI increased as the number of CDMCs increased: SMs with 0-1, 2-3, 4-5 and ≥6 general CDMCs had CDI prevalences of 0.5%, 3.2%, 6.7%, and 10.9%, respectively. CONCLUSION: In a young, physically active population CDI was associated with many CDMCs involving multiple physiological systems.