Does group-based high-intensity aerobic interval training improve the inflammatory status in patients with chronic heart failure? A randomized controlled trial.

BACKGROUND Chronic heart failure (CHF) is a multifaceted syndrome associated with endothelial dysfunction and increased inflammation. Despite the existing controversies regarding the appropriate training modality, it is widely accepted that supervised cardiac rehabilitation (CR) interventions lead to pro-inflammatory biomarkers reduction and cellular adhesion molecules in patients with CHF. AIM To quantify the effects of 12-week group-based high-intensity aerobic interval training (HIAIT)/modified group-based HIAIT intervention (m-Ullevaal) vs. moderate continuous training (MICT) on serum levels of pro-inflammatory biomarkers. DESIGN Single-blind, two-arm, prospective randomized controlled trial conducted on CHF outpatients performing group-based CR interventions throughout a 12-week period. SETTING Medical Center of Outpatient Rehabilitation and Sport Medicine, Plovdiv, Bulgaria. POPULATION A total of 120 outpatients of both genders, mean age of 63.73 ± 6.68 years, with stable CHF (NYHA classes II to IIIB, were randomly assigned to HIAIT/ m-Ullevaal (N. = 60) or to MICT (N. = 60) group. METHODS Functional exercise capacity (FEC) of the eligible subjects was evaluated through 6-minute walk test (6MWT) and peak oxygen uptake. Blood samples were drawn at baseline, after 12 weeks follow-up for analyses of C-reactive protein (CRP), tumor necrosis factor-α (TNFα) and cellular adhesion molecules (CAM). RESULTS Significant decreases in the serum levels of CRP (P = 0.029), TNF-α (P = 0.036), and vascular cell adhesion molecule-1 (VCAM-1) (P = 0.040), were observed after 48 training sessions in the group-based HIAIT/m-Ullevaal intervention, except for intercellular adhesion molecule-1 (ICAM-1), which was higher in the MICT (P = 0.034). FEC was significantly inversely related to CRP (r = -0.72, p < 0.05), and the levels of VCAM-1 (r = - 0.68, P< 0.05). CONCLUSIONS Both group-based CR interventions (HIAIT/m-Ullevaal and MICT) significantly reduced the serum levels of CRP, TNF- α, ICAM-1 and VCAM in patients with CHF. However, selected pro-inflammatory biomarkers changes and CAMs favorably decreased in the group-based HIAIT/m-Ullevaal intervention. The responses on serum levels of pro-inflammatory biomarkers and CAMs are dependent upon the type, intensity, and CR intervention duration. CLINICAL REHABILITATION IMPACT The group-based high-intensity aerobic interval training reduces significantly the pro-inflammatory biomarkers and cellular adhesion molecules in patients with chronic heart failure.