Amado CA, et al. - Researchers estimated the link between the Sarcopenia Index [SI; a novel way to estimate muscle mass based on the ratio of serum creatinine (produced exclusively by muscle)/cystatin C (produced by all nucleated body cells] and several important clinical features in chronic obstructive pulmonary disease (COPD), as well as its potential utility as a predictor of COPD exacerbations and hospital admissions. For this purpose, they compared SI between stable COPD outpatients and a healthy control group. Findings revealed correlation of serum creatinine/serum cystatin C ratio with several COPD characteristics. Lower levels of SI were detected in patients with a modified Medical Research Council dyspnea score ≥2, patients with a COPD Assessment Test score ≥10, and patients with a high risk of exacerbation, compared with patients without these characteristics. The ratio serum creatinine/serum cystatin C could be used to predict COPD hospitalization.