PRTN3 and obesity due to melanocortin 4 receptor deficiency: The subgroup analysis stratified by ACPA seropositivity revealed that RRs were 1.34 (0.98 to 1.82), 1.47 (0.94 to 2.30), and 1.18 (0.75 to 1.87) for obesity versus non-obesity, obesity versus normal weight, and overweight versus normal weight in ACPA-seronegative RA patients, and 1.39 (1.07 to 1.79), 1.47 (1.09 to 1.98), and 1.34 (1.08 to 1.65) in ACPA-seropositive RA patients, respectively.