Effect of high-intensity interval training on cardiovascular disease risk factors and body composition in psoriatic arthritis: a randomised controlled trial

BACKGROUND: Psoriatic arthritis (PsA) is associated with an accumulation of cardiovascular disease (CVD) risk factors. The aim of this study was to evaluate the effect of high-intensity interval training (HIIT) on CVD risk factors in patients with PsA. METHODS: We randomly assigned 61 patients with PsA (41 women and 20 men) to an intervention group performing HIIT for 11 weeks or a control group who were instructed to not change their physical exercise habits. Outcomes were assessed at 3 and 9 months with measures on maximal oxygen uptake (VO(2max)), fat percentage and Body Mass Index (BMI). We used linear mixed models to calculate mean difference with 95% CI between the groups according to the intention-to-treat principle. RESULTS: At 3 months, the HIIT group had a 3.72 mL/kg/min (95% CI 2.38 to 5.06) higher VO(2max) and a 1.28 (95% CI −2.51 to −0.05) lower truncal fat percentage than controls. There was also some evidence that the HIIT group had lower total fat percentage (−0.80; 95% CI −1.71 to 0.10) and slightly lower BMI (−0.31; 95% CI −0.78 to 0.17) than the control group. At 9 months, the HIIT group had still a higher VO(2max) (3.08; 95% CI 1.63 to 4.53) than the control group, whereas the difference in other factors were small. CONCLUSION: In patients with PsA, 3 months with HIIT was associated with a substantial increase in VO(2max) and a reduction in truncal fat percentage compared with controls. The beneficial effect on VO(2max) was also sustained through 9 months. TRIAL REGISTRATION NUMBER: NCT02995460.