An increase in body mass index (BMI) may increase the risk of developing rheumatic diseases, according to a report from MedPage Today. In a study published by Karlsson et al in Arthritis & Rheumatology, investigators used the UK Biobank cohort to analyze the impact of BMI on several rheumatic diseases among nearly 362,000 patients. The investigators found that one standard deviation increase in BMI increased the incidence rate of psoriatic arthropathy (incidence rate ratio [IRR] = 1.80, 95% confidence interval [CI] = 1.31–2.48), gout (IRR = 1.73, 95% CI = 1.56–1.92), rheumatoid arthritis (IRR = 1.52, 95% CI = 1.36–1.69), osteoarthritis (IRR = 1.49, 95% CI = 1.43–1.55), and inflammatory spondylitis (IRR = 1.34, 95% CI = 1.14–1.57). Further, a higher BMI was a stronger risk factor of psoriatic arthropathy and gout in female patients vs male patients and of osteoarthritis in premenopausal vs postmenopausal patients. The investigators also discovered that those with a normal BMI who experienced a one-unit increase in their BMI were at a greater risk of developing gout compared with those who already had a low or high BMI. They emphasized that unlike previous studies, they sought to establish whether BMI may have a causal effect on the development of rheumatic diseases. The investigators suggested that patients at risk of developing the diseases should partake in interventions to decrease their BMI. “For some diseases such as gout, weight gain prevention and keeping the [patients] at risk in the normal range of BMI could possibly be of more importance [than decreasing BMI],” concluded lead study author Torgny Karlsson, PhD, a statistician in the Department of Immunology, Genetics, and Pathology at Uppsala University.