A large proportion of RA inpatients, mainly women, had rheumatoid cachexia. The muscle wasting was explained by inflammatory activity and physical disability as well as low bioavailable IGF-1.

Objective: To evaluate diagnostic instruments for assessment of nutritional status in patients with rheumatoid arthritis (RA) in relation to objective body composition data. Subjects and methods: Study subjects include 60 in-ward patients (83% women, median age 65 years). Anthropometric measures and the nutritional tools Mini Nutritional Assessment (MNA), Subjective Global Assessment (SGA), Malnutrition Universal Screening Tool (MUST) and Nutritional Risk Screening tool 2002 (NRS-2002. Body composition was determined by dual-energy X-ray absorptiometry and fat-free mass index (FFMI; kg/m 2 ) and fat mass index (FMI; kg/m 2 ) were calculated. Results: Mean body mass index (BMI) for RA women and men were 24.4 and 26.9 kg/m 2 , respectively. Twelve per cent of the women and none of the few men had BMIo18.5 kg/m 2 , that is, the cutoff value for malnutrition. FFMI indicated 52% of the women and 30% of the men to be malnourished. The sensitivity and specificity for BMI to detect malnutrition according to FFMI were 27 and 100%, whereas for arm muscle circumference the sensitivity was 36% and the specificity 89% and for triceps skin fold 43 and 93%, respectively. For MNA, sensitivity was 85% and specificity 39% and for SGA 46 and 82%. Both MUST and NRS-2002 had sensitivity of 45% and specificity of 19%. Conclusion: A large proportion of in-ward RA patients had reduced FFMI. Concurrent elevation of fat mass made BMI a nonreliable tool to detect malnutrition. Of the tested clinical evaluation tools, MNA might be used as a screening instrument, but because of its low specificity it should be followed by body composition determination.

RA patients treated with low-dose prednisolone had significantly higher FM than patients without prednisolone, an effect that was independent of current inflammation. However, there was no association between prednisolone treatment and muscle mass or BMD. Thus, the net effect of prednisolone on body composition and bone is different in inflammatory diseases such as RA.