The role of insomnia in the association between posttraumatic stress disorder and hypertension

OBJECTIVE: Posttraumatic stress disorder (PTSD) is associated with incident hypertension. Although this relationship is poorly understood, PTSD is also associated with insomnia symptoms, which increases the risk for hypertension. Whether insomnia contributes to PTSD-associated risk for hypertension is unknown. METHODS: We examined self-report survey and electronic health record data from 1109 participants in the Women Veterans Cohort Study (mean age: 43.8 ± 10.9 years; 52% women, 81% White) to assess the cross-sectional associations between PTSD symptom severity, recent symptoms of insomnia, and hypertension, defined as self-reported treatment for high blood pressure in the last year. Structural equation modeling was used to examine whether insomnia symptoms mediate the association between PTSD and hypertension. RESULTS: PTSD symptom severity was associated with hypertension (r = 0.09, P  0.001). PTSD symptom severity and hypertension were each associated with the insomnia symptoms difficulty falling asleep, difficulty staying asleep, and worry/distress about sleep problems (PTSD: rs = 0.58--0.62, P   0.001; hypertension: rs = 0.07--0.10, P   0.001). A latent variable derived from those symptoms mediated 9% of the association between PTSD symptom severity and hypertension (P = 0.02). CONCLUSION: In this study of young and middle-aged Veterans, insomnia symptoms mediated the association between PTSD and hypertension. Difficulties falling asleep and maintaining sleep and related distress may be particularly deleterious for cardiovascular health in Veterans. Longitudinal data is required to further investigate the associations between PTSD, insomnia, and hypertension.