Background Rheumatoid arthritis (RA) is a chronic and inflammatory disease that besides articular symptoms leads to loss of muscle mass in presence of stable or increased fat mass (FM), condition defined as rheumatoid cachexia (RC). RC is associated with a worse prognosis, but it is still overlooked in clinical practice.
Objectives To evaluate the prevalence of rheumatoid cachexia (RC) in patients with rheumatoid arthritis (RA) and determine its correlation with the features of RA, the level of physical activity and with the current therapy.
Methods Ninety one RA patients in a cross-sectional study underwent total body dual-energy x-ray absorptiometry (DXA) for measurement of total and regional fat mass index (FMI; Kg/m2), lean mass index (LMI; Kg/m2), bone mineral content (BMC; Kg/m2) and fat free mass index (FFMI; Kg/m2) to assess the prevalence of RC. The associations of measures of body composition with RA features - age, diagnosis time, Health Assessment Questionnaire (HAQ), Disease Activity Score in 28 joints (DAS 28), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) -, level of physical activity (measured by International Physical Activity Questionnaire – IPAQ) and current therapy were explored.
Results Mean age was 56.8±7.3, disease duration 9 years (3 – 18), DAS28 3.65±1.32, HAQ 1.12 (0.25 – 1.87) and use duration of biological agents was 25 months (17.8 – 52.5). 17% of the patients had FFMI below the 10th percentile and FMI above the 25th percentile of a reference population and 33% of the patients had FFMI below the 25th percentile and FMI above the 50th percentile, condition known as RC, according to the more recently used definitions. FFMI correlated negatively only with age (r=-0.219; p=0.037) and disease duration (rs=-0.214; p=0.042). FMI correlated positively with CRP (rs=0.229; p=0.029), ESR (rs=0.235; p=0.025), DAS 28 (rs=0.273; p=0.009) and HAQ (rs=0.297; p=0.004). Among patients under biologics, 3.8% (n=1) had RC versus 23% (n=15) of those not taking biologics (p=0.033), according to the stricter definition.
Conclusions The prevalence of RC was considerable and deserves additional research. Besides that, patients under biological therapy had lower prevalence of RC, suggesting a protective effect of biological agents.
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Disclosure of Interest None declared