Randomized Trial Of Resistance Exercise And Follow-up In Gulf War Veterans With Chronic Musculoskeletal Pain

Abstract

Approximately 30% of US Veterans of the Persian Gulf War currently suffer from Gulf War illness, a chronic multisymptom condition without clear pathology. Chronic muscle pain (CMP) is a primary complaint of Veterans with Gulf War illness. Generally, prognosis is poor and few effective treatments have been substantiated. Structured aerobic and resistance exercise have both proven beneficial in civilians with similar conditions (e.g., fibromyalgia), but have not been rigorously tested in Gulf Veterans with CMP. PURPOSE: To evaluate the influence of a progressive, 16-week, resistance exercise training (RET) program on fitness, symptoms, mood, and Patients’ Global Impression of Change (PGIC) in Gulf Veterans with CMP during training and at 6- and 12-months follow-up. METHODS: Fifty-four Gulf Veterans with CMP were randomly assigned to 16 weeks of RET (n = 28) or a wait-list control (n = 26). Exercise consisted of twice weekly sessions with a personal trainer, initiated at a low intensity (25-35% of estimated maximum) with progression as tolerated. At baseline, 6, 11, and 17 weeks, all participants were evaluated on symptoms, mood, and PGIC. Participants returned for further evaluation 6 and 12 months after the intervention. Analyses of symptom and mood outcomes were conducted via separate linear mixed models with group and time as fixed effects and baseline values as a covariate to control for initial differences. A similar model, without a baseline covariate, was employed to evaluate PGIC scores. RESULTS: No adverse events due to the intervention were reported. Gulf Veterans assigned to RET completed 88% of training sessions and exhibited strength increases of >20% for 7 of 8 lifts. Estimates for the fixed effects and their interactions were not significant for symptom or mood outcomes (p > 0.05). A significant interaction between factors was observed for PGIC (F1,163 = 16.94, p = 0.00006). This interaction was characterized by greater improvement since baseline for RET at each time point, until the 12-month follow-up. CONCLUSIONS: RET appears to be a safe and effective method of improving fitness and patient perception, without symptom exacerbation, in Gulf Veterans with CMP. Supported by a grant from the U.S. Department of Veterans Affairs #I01 CX000383