Little is known about body composition in patients with PsA. We compared body composition parameters in PsA patients and healthy controls, and then investigated the effects of ustekinumab (UST) on body composition in patients with PsA.
At baseline, 30 PsA patients were compared cross-sectionnally with 60 non-PsA healthy controls matched for age, sex, menopausal status and body mass index. Thirty active PsA patients treated with UST were included in a 6-month open follow-up study. Body composition parameters were measured at baseline and 6 months of treatment.
Body composition parameters were different in PsA patients compared to healthy controls: in PsA patients, total and appendicular lean mass were lower (p=0.013 and p=0.010 respectively), whereas total fat mass was higher (p<0.001). In 30% of the PsA patients, skeletal muscle mass was below the cut-off for low muscle quantity (men 7.26 kg/m2, women 5.5 kg/m2), whereas no such change was observed in the control group. After 6 months of treatment with UST, there was no significant change in BMI in 18 of the PsA patients. Total lean mass decreased slightly (p=0.046), whereas fat mass tended to increase, but not significantly. No significant changes in appendicular lean mass and skeletal muscle mass index were observed.
In this study, we found that PsA patients had higher fat mass and lower lean mass than healthy controls. At 6-months of treatment, total lean mass decreased slightly, whereas fat mass tended to increase, but not significantly.