2 - (Sym 45) Neurobiological and Psychological Benefits of Exercise in Chronic Pain and PTSD: a Proof of Concept Study

We assessed the effects of acute cardiopulmonary exercise testing (CPET), as well as 3 months of aerobic exercise training, on levels of the equipotent GABAergic neurosteroids allopregnanolone and pregnanolone (ALLO + PA). Relationships of these anti-stress, anti-nociceptive neurobiological mechanisms to posttraumatic stress disorder (PTSD) severity and pain-related interference were examined among sedentary civilians and Veterans with chronic pain (CP) and PTSD (N=10 completers; mean age 39.6 ± 9.8 years; 50% female; 60% Veterans). A baseline CPET established baseline fitness (peakVO₂) and heart rate at peak exercise in order to tailor a 12-week (3 x 30-minute sessions/week) individualized, moderate-to-vigorous intensity aerobic exercise training program. A CPET was repeated at completion of exercise training.

A.    ALLO+PA levels: There was a five-fold increase in resting plasma ALLO+PA levels from pre-training [2074.8 (410.2) pg/mL)] to post-training [10231.0 (9902.6) pg/mL].

B.    PTSD Severity: CAPS-5 scores improved across exercise training, with a near significant effect (p=.06) among 10 participants with CP/PTSD: Screening CAPS_baseline=27.7(9.8); CAPS_{post-training}=14.2(10.35), partial n²=.26. Self-rated PTSD Check List (PCL-5) scores did not improve significantly, but showed a medium effect size: PCL_baseline=28.22(12.37); PCL_{post-training}=18.11(11.01), partial n²=.10.

C.    Pain-Related Interference: Pain-related interference showed a large effect size for improvement in seven participants with CP/PTSD across exercise training (pain interference_screen=4.16(1.1); pain interference_{post-training}=2.5(1.86), partial n²=.18.

A 3-month individualized progressive aerobic exercise training program was associated with increases in resting plasma ALLO+PA levels and imrpovements in PTSD severity and pain-related interference.  Larger controlled studies are needed to replicate and generalize the findings to individuals with less stringent eligibility critera (e.g., with use of chronic psychiatric medication) and further delineate the impact of moderate to vigorous aerobic exercise on PTSD and CP, among other important comorbid conditions shared between CP+PTSD.