Linauskas A, et al. - in this population-based prospective cohort study, the association between bioimpedance-derived total body fat percentage, waist circumference, and body mass index (BMI) and the subsequent development of rheumatoid arthritis (RA) was investigated using 55,037 patients enrolled in the Danish Diet, Cancer, and Health cohort. In females, they observed 10% higher overall RA risk for each 5% increment of total body fat, 5% greater for each 5-cm increase in waist circumference, and approximately 50% higher in those whose BMI was in the obese range vs normal range BMI. They reported these positive associations for other RA cases. They did not find clear relationships between body fat percentage, waist circumference, or BMI and RA in men.