Cardiorespiratory Fitness Is Associated With Better Cardiometabolic Health and Lower PTSD Severity in Post-9/11 Veterans.

Abstract

Post-traumatic stress disorder (PTSD) is associated with an increased risk of cardiovascular and metabolic diseases and physical inactivity. Cardiorespiratory fitness (CRF), which is modifiable by physical activity, is a strong independent predictor of cardiometabolic health. However, the relationship between CRF and cardiometabolic health in veterans with PTSD is unknown. Thus, this study aimed to explore the cross-sectional relationships among CRF, indices of cardiometabolic health (ie, HbA1c, blood lipids, blood pressure, waist-hip ratio, and body mass index), and PTSD severity in veterans with PTSD. This study was approved by the local Institutional Review Board. All participants were informed of the study risks and provided consent prior to participation. Participants (n=13) completed a cardiopulmonary exercise test, a fasting blood draw, and the Clinician Administered PTSD Scale. Correlations between CRF and cardiometabolic health were examined with Spearman's rank correlations, and differences in PTSD symptom severity were explored as a function of CRF (ie, low-to-moderate vs. high CRF), using multiple linear regression. Peak oxygen uptake ($\dot{\mathrm{V}}$O2peak) was correlated with high-density lipoproteins rho=0.60, P=0.04 and diastolic blood pressure rho=-0.56, P=0.05. Ventilatory threshold was correlated with HbA1c rho=-0.61, P=0.03 and diastolic blood pressure rho=-0.56, P=0.05. Higher CRF was associated with lower total PTSD severity standardized β=-0.84, P=0.01, adjusted R2=0.47, total Cluster C symptoms (avoidance/numbing) β=-0.71, P=0.02, adjusted R2=0.49, and total Cluster D symptoms (hyperarousal) β=-0.89, P=0.01, adjusted R2=0.41, while adjusting for age and smoking status. These preliminary findings suggest that CRF and by proxy physical activity may be important factors in understanding the increased risk of cardiovascular and metabolic disease associated with PTSD.