Differences in body mass index, waist circumference, and waist-to-hip ratio in patients with rheumatoid arthritis: association with serum adiponectin and disease parameters

Abstract

Objective The aim of this study was to investigate differences in BMI, waist circumference (WC), and waist-to-hip ratio (WHR) in rheumatoid arthritis (RA) patients and their association with serum adiponectin and disease parameters. Patients and methods Fifty RA patients and 25 matched healthy controls were included. Anthropometric measurements, disease status, and serum adiponectin level were assessed. Results Out of 50 RA patients, 48% had normal BMI (18.5–24.9 kg/m2), 20% had BMI in the range of 25.0–29.9 kg/m2, which is considered to be overweight, and 32% were obese, with BMI greater than 30 kg/m2. Almost similar findings were observed by the measurements of WC − that is, 34% of patients were obese ‘abdominal obesity’. However, the percentage of obese patients increased to 42% when classified as per WHR ‘truncal obesity’. Serum adiponectin was significantly increased in RA patients compared with controls (P=0.002). Significant negative correlations of BMI and WC with serum adiponectin level were found (r=−0.9, P≤0.001; r=−0.7, P≤0.001, respectively). There were positive correlations of WHR with Disease Activity Score 28 (r=0.3, P=0.047), Multidimensional Health Assessment Questionnaire (r=0.3, P=0.04), and ultrasound Disease Activity Score (r=0.4, P=0.04), whereas there was a significant negative correlation with ultrasound erosion rate (r=−0.3, P=0.02). Conclusion BMI, WC, and WHR measurements should be used and encouraged in the RA population. Our findings suggested that WHR was better associated with disease activity, disability, and severity than with other measures.

Keywords

• anthropometric measurements
• rheumatoid arthritis
• serum adiponectin