Mediterr J Rheumatol 2016;27(2):48-54
Body-size phenotypes and cardiometabolic risk in Rheumatoid Arthritis (Short Title: Subgroups of obesity in RA)
Authors Information

1: Department of Sport and Exercise Science, University of Thessaly, Trikala, Greece

2: Institute of Human Performance & Rehabilitation, Centre for Research and Technology Thessaly, Trikala, Greece

3: Department of Rheumatology, Dudley Group NHS Foundation Trust, Russell’s Hall Hospital, Dudley, West Midlands, UK

4: School of Sport, Performing Arts & Leisure, Wolverhampton University, West Midlands, UK

5: Arthritis Research UK Epidemiology Unit, University of Manchester, Manchester, UK

Objectives: Obesity is a significant contributor to metabolic complications. However, such complications are not uniform in people with similar body-size. The existence of normal-weight individuals with and obese individuals without metabolic complications has been described in the general population and is important in the context of cardiovascular disease (CVD). This has not been investigated in rheumatoid arthritis (RA), a condition associated with increased cardiometabolic risk. This study aims to identify the prevalence and predictors of body-size phenotypes in RA and investigate their associations with CVD risk. Methods: Body mass index (BMI: kg/m2), body fat (BF) and fat free mass (FFM), RA characteristics and CVD risk factors were assessed in 363 (262 female) volunteers with RA. Abnormal cardiometabolic status was defined as the presence of >1 of the following: hypertension, increased triglycerides or increased Low or reduced High Density Lipoprotein, high glucose, insulin resistance. Results: Among normal-weight, overweight, and obese participants, 25%, 45.8%, 57.1% respectively were metabolically abnormal. Old age (B= 1.032, err=0.011; p= 0.005), waist circumference (B= 1.057, err= 0.011; p= 0.000), and smoking cessation (B= 1.425, err= 0.169; p=0.036) were significant predictors for metabolic abnormality. Conclusions: A significant number of RA patients present with different body-size and metabolic phenotypes. Body Mass Index alone is not a sufficient indicator of cardiometabolic risk in RA; this may have significant implications in their CVD risk evaluation. Body fat distribution seems to be a significant contributor to such abnormalities. Further research is needed, focusing on the metabolic properties of specific adipose depots of RA patients.