Body composition profiling in a Dutch sarcoidosis population.

Muscle atrophy is a common problem in many chronic inflammatory diseases. It may occur as part of a generalized wasting process (cachexia) or be hidden due to preservation of fatmass (sarcopenia, sarcopenic obesity).

OBJECTIVE

The aim of this study was to assess the prevalence of cachexia and muscle atrophy in sarcoidosis and their association with disease activity and severity.

METHODS

A cross-sectional study was performed in 423 sarcoidosis patients. Fat-free mass was assessed as an indirect measure of muscle mass by bioelectrical impedance analysis. Patients were stratified based on body mass index (BMI) and fat-free mass index (FFMI).Muscle atrophy was defined as FFMI <15 kg/m2 for women and <17 kg/m2 for men corresponding to <10th percentile of current reference values; cachexia as BMI <20 combined with muscle atrophy.Multivariate linear regression models were used to adjust for potential confounders.

RESULTS

Of the patients examined, 58% were categorized as overweight (37%) or obese (21%), whereas 7% were underweight.Muscle atrophy was present in 25% and cachexia in 5%. Patients with muscle atrophy showed significantly worse lung function (DLCO, FEV1, FVC, all p-values <0.01) and impaired exercise capacity (VO2max, p<0.001). The associations were most pronounced in patients with cachexia. Associations remained significant after adjustment for potential confounders.

CONCLUSIONS

Muscle atrophy was present in 25% of sarcoidosis patients and was associated with more severe pulmonary disease. Prospective studies with longitudinal design are needed to assess the association between muscle atrophy and disease severity in sarcoidosis.