The influence of exercise training on chronotropic competence in individuals with Systemic Lupus Erythematosus prescribed with glucocorticoid pulse therapy.

Abstract

Patients with severe LES, particularly those whose severity warrants treatment with glucocorticoid pulse-therapy face many challenges to their physical and metabolic health. A combination of factors related both to their condition, and to the glucocorticoid treatment may combine to influence their chronotropic competence, which is defined as the ability of the heart to increase its rate commensurate with increased activity or demand. Previous research indicates that individuals with less severe LES issues with chronotropic incompetence, and that this can be reduced by exercise training. This has never been evaluated in individuals with severe LES, however, and it is unknown whether this group are also amenable to the potential benefits of exercise training on this parameter. Hence, the aim of this randomized, controlled, parallel-group trial is to investigate the effects of a home-based, supervised, 6-month exercise training program on chronotropic competence and exercise tolerance in women with SLE who recently underwent glucocorticoid pulse therapy. Following baseline assessments, participants will be randomized to either the control (CON) or exercise (EX) groups. Participants in both groups will receive usual care, while those randomized to the EX group will also follow a multi-modal training program. Outcomes will be examined at baseline and after 3 and 6 months. Primary outcomes include parameters related to the cardiac response to incremental exercise, including VO2 peak, aerobic and anaerobic thresholds, chronotropic reserve, change in HR from rest to the ventilatory anaerobic threshold (VAT), the respiratory compensation point (RCP) and exercise peak. Additionally, heart rate recovery will be assessed as the change in heart rate from peak exercise to 1, 2 and 6 minutes post-exercise.