Potential neurobiological benefits of exercise in chronic pain and posttraumatic stress disorder: Pilot study

This pilot study assessed the effects of cardiopulmonary exercise testing and cardiorespiratory fitness on plasma neuropeptide Y (NPY), allopregnanolone and pregnanolone (ALLO), cortisol, and dehydroepiandrosterone (DHEA), and their association with pain sensitivity. Medication-free trauma-exposed participants were either healthy (n = 7) or experiencing comorbid chronic pain/posttraumatic stress disorder (PTSD) (n = 5). Peak oxygen consumption (VO2) during exercise testing was used to characterize cardiorespiratory fitness. Peak VO2 correlated with baseline and peak NPY levels (r = 0.66, p < 0.05 and r = 0.69, p < 0.05, respectively), as well as exercise-induced changes in ALLO (r = 0.89, p < 0.001) and peak ALLO levels (r = 0.71, p < 0.01). NPY levels at the peak of exercise correlated with pain threshold 30 min after exercise (r = 0.65, p < 0.05), while exercise-induced increases in ALLO correlated with pain tolerance 30 min after exercise (r = 0.64, p < 0.05). In contrast, exercise-induced changes in cortisol and DHEA levels were inversely correlated with pain tolerance after exercise (r = -0.69, p < 0.05 and r = -0.58, p < 0.05, respectively). These data suggest that cardiorespiratory fitness is associated with higher plasma NPY levels and increased ALLO responses to exercise, which in turn relate to pain sensitivity. Future work will examine whether progressive exercise training increases cardiorespiratory fitness in association with increases in NPY and ALLO and reductions in pain sensitivity in chronic pain patients with PTSD.

Gender differences in substance use treatment utilization in the year prior to deployment in Army service members

Although military men have heavier drinking patterns, military women experience equal or higher rates of dependence symptoms and similar rates of alcohol-related problems as men at lower levels of consumption. Thus, gender may be important for understanding substance use treatment (SUT) utilization before deployment. Military health system data were analyzed to examine gender differences in both substance use diagnosis (SUDX) and SUT in 152,447 Army service members returning from deployments in FY2010. Propensity score analysis of probability of SUDX indicated that women had lower odds (AOR: 0.91, 95% CI: 0.86-0.96) of military lifetime SUDX. After adjusting for lifetime SUDX using propensity score analysis, multivariate regression found women had substantially lower odds (AOR: 0.61; 95% CI: 0.54-0.70) of using SUT the year prior to deployment. Findings suggest gender disparities in military-provided SUT and a need to consider whether military substance use assessment protocols are sensitive to gender differences.