A randomized two-year study of the effects of dynamic strength training onmuscle strength, disease activity, functional capacity, and bone mineral density in early rheumatoid arthritis

Objective. To evaluate the impact of a 2-year program of strength training on muscle strength, bone mineral density (BMD), physical function, joint da mage, and disease activity in patients with recent-onset (<2 years) rheumat oid arthritis (RA). Methods. In this prospective trial, 70 RA patients were randomly assigned t o perform either strength training (all major muscle groups of the lower an d upper extremities and trunk, with loads of 50-70% of repetition maximum) or range of motion exercises (without resistance) twice a week, all were en couraged to engage in recreational activities 2-3 times a week. All patient s completed training diaries (evaluated bimonthly) and were examined at 6-m onth intervals. All were treated with medications to achieve disease remiss ion. Maximum strength of the knee extensors, trunk flexors and extensors, a nd grip strength was measured with dynamometers. BMD was measured at the fe moral neck and lumbar spine by dual x-ray densitometry. Disease activity wa s determined by the Disease Activity Score, the extent of joint damage by t he Larsen score, and functional capacity by the Health Assessment Questionn aire (HAQ); walking speed was also measured. Results. Sixty-two patients (31 per group) completed the study. Strength tr aining compliance averaged 1.4-1.5 times/week. The maximum strength of all muscle groups examined increased significantly (19-59%) in the strength-tra ining group, with statistically significant improvements in clinical diseas e activity parameters, HAQ scores, and walking speed. While muscle strength , disease activity parameters, and physical function also improved signific antly in the control group, the changes were not as great as those in the s trength-training group. BMD in the femoral neck and spine increased by a me an <plus/minus>SD of 0.51 +/- 1.64% and by 1.17 +/- 5.34%, respectively, in the strength-training group, but decreased by 0.70 +/- 2.25% and 0.91 +/- 4.07% in the controls. Femoral neck BMD in the 17 patients with high initia l disease activity (and subsequent use of oral glucocorticoids) remained co nstantly at a statistically significantly lower level than that in the othe r 45 patients. Conclusion. Regular dynamic strength training combined with endurance-type physical activities improves muscle strength and physical function, but not BMD, in patients with early RA, without detrimental effects on disease act ivity.