Relevance of the new pre-cachexia and cachexia definitions for patients with rheumatoid arthritis

Background & aims: The recently proposed definitions of 'pre-cachexia' and 'cachexia' might offer new possibilities for the detection of malnutrition in patients with rheumatoid arthritis (RA). Methods: The prevalence of different components of nutritional status and the compiled definitions of 'precachexia' and 'cachexia' were measured in a cohort of 103 patients with moderately active RA. Nutritional status was determined by measuring unintentional weight loss, BMI, and muscle strength. Bio-electrical Impedance Analysis (BIA) was used to determine fat free mass index (FFMI) and fat mass index. In addition, appetite, pain, fatigue, and inflammatory activity were assessed. The prevalence of 'pre-cachexia' and 'cachexia' was calculated from different combinations of these parameters. Results: 20% of the study population had a low FFMI (<10th percentile), and 95% had a decreased muscle strength (<lowest tertile). Weight loss and loss of appetite, both essential elements in the newly proposed (pre-)cachexia definitions, were uncommon. The prevalence of 'pre-cachexia' and 'cachexia' was both 1% (n = 1). Conclusions: In spite of altered body composition and impaired body function, the recently proposed definitions of both 'pre-cachexia' and 'cachexia' were unable to identify and diagnose impaired nutritional status in RA patients mainly because of low prevalences of weight loss and decreased appetite.