OBJECTIVE: In this interventional weight loss study, health-related quality of life (HRQoL), anxiety, depression and fatigue were compared at baseline (BL) and at 12 months (M12) in patients with psoriatic arthritis (PsA) and controls. METHODS: PsA patients (n = 39) between 25 and 75 years of age, with body mass index (BMI) ≥ 33 kg/m RESULTS: In PsA patients, physical HRQoL, as demonstrated by the physical component summary (PCS) of SF-36, improved from median (IQR) 34 (25-45) at BL to 43 (34-50) at M12, p = 0.009. No significant effect on mental HRQoL, demonstrated by the mental component summary (MCS) score, was seen. Similarly in controls, PCS significantly improved (median IQR, 44 (36-50) at BL to 52 (44-55) at M12, p <
0.001), whereas no significant improvement was seen in MCS. Anxiety and depression decreased significantly in both PsA patients and controls. CONCLUSIONS: The weight loss intervention was associated with significant improvements in physical HRQoL, as well as anxiety and depression, in PsA patients and controls. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02917434, registered on September 21, 2016, retrospectively registered.