Sarcopenia in systemic sclerosis: the impact of nutritional, clinical, and laboratory features

We evaluated the presence of sarcopenia in a population of systemic sclerosis (SSc) patients, with respect to nutritional, clinical, and laboratory features. A total of 62 patients who met the ACR/EULAR 2013 classification criteria were enrolled. Sarcopenia was defined according to the Relative Skeletal Mass Index (RSMI) and hand grip strength (HGS). Body composition was assessed with the calculation of the Body Mass Index (BMI), lean body mass (LBM) and fat mass (FM). Malnutrition was evaluated according to the ESPEN criteria. Clinical evaluation included nailfold capillaroscopy and skin evaluation by modified Rodnan Skin Score (mRSS), pulmonary function tests (PFT) with diffusing capacity for carbon monoxide adjusted for hemoglobin (DLCO), high-resolution computed tomography (HR-CT) of the lungs, echocardiography and high-resolution manometry (HRM) for esophageal involvement. Laboratory evaluation included erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), hemoglobin, creatinine, creatine kinase (CK), transaminases, lipid profile, glycemia, albumin, and vitamin-D. Antinuclear antibodies (ANA) and extractable nuclear antigens (ENA) were also assessed. Considering RSMI, the prevalence of sarcopenia is 42%. In this case, age, malnutrition, disease duration, mRSS, capillaroscopy score, esophageal involvement, ESR, and ANA titer are higher in the sarcopenic group, while DLCO and LBM are lower. Considering HGS, the prevalence of sarcopenia is 55%. Age, disease duration, malnutrition, FM, mRSS, capillaroscopy score, esophageal involvement, ESR, and ENA positivity are higher in the sarcopenic group, while DLCO is lower. By using both RSMI and HGS to assess sarcopenia in SSc, the results of this study demonstrated that this condition correlates with different nutritional, clinical, and biochemical parameters associated with the worsening of the disease.