Reduced calf circumference is an independent predictor of worse quality of life, severity of disease, frequent exacerbation, and death in patients with chronic obstructive pulmonary disease admitted to a pulmonary rehabilitation program: A historic cohort study

Abstract

Background: Muscle wasting is associated with worse outcomes in chronic obstructive pulmonary disease (COPD) patients. We assessed the association of calf circumference (CC) measurements with clinical outcomes in COPD patients referred to an outpatient pulmonary rehabilitation program (PRP).

Methods: In this single-center, retrospective study, we analyzed demographic and clinical data ( spirometry tests, comorbidities, COPD exacerbations, dyspnea scoring, exercise capacity, quality-of-life scores, BMI, CC measurements, and all-cause deaths [for 2 years]) from COPD patients PRP medical records. Patients were grouped according to CC into reduced CC (male, ≤34 cm; female, ≤33 cm) or adequate CC groups.

Results: We evaluated 144 patients (aged 64.6 ± 8.5 years; mostly males; forced expiratory volume in 1 s, 40.3% ± 15.8%, predicted). Eighteen patients (12.5%) died during the 2 years of follow-up. Logistic regression showed that patients with reduced CC were more likely to present worse outcomes compared with COPD patients with adequate CC: more advanced disease severity (odds ratio [OR] = 5.09; 95% CI, 2.00-12.96), COPD frequent exacerbators (OR = 2.34; 95% CI, 1.11-4.91), worse total quality-of-life score (OR = 2.70, 95% CI, 1.22-6.00), and higher mortality (OR = 3.69; 95% CI, 1.06-12.87).

Conclusion: Reduced CC in COPD patients under initial assessment for PRP admission was associated with disease severity, frequent exacerbation, poor health status, and higher mortality in 2 years of follow-up. Considering its clinical applicability, CC measurement should be introduced in the nutrition assessment of COPD patients admitted to the PRP.

Keywords: COPD; muscle mass; nutrition assessment; pulmonary rehabilitation.