Global prevalence of malnutrition in patients with chronic obstructive pulmonary disease: Systemic review and meta-analysis

Malnutrition is a significant comorbidity among chronic obstructive pulmonary disease (COPD), but it has been often ignored. To date, the prevalence of malnutrition and its association with clinical parameters in the patients with COPD have not been well described. We aimed to investigate the prevalence of malnutrition and the prevalence of at-risk for malnutrition among COPD and the clinical impact of malnutrition on patients with COPD in a systematic review and meta-analysis.PubMed, Embase, Cochrane Library, and Web of Science were searched for articles describing the prevalence of malnutrition and/or at-risk for malnutrition from January 2010 to December 2021. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Meta-analyses were performed to determine the prevalence of malnutrition and at-risk for malnutrition and the clinical impact of malnutrition on patients with COPD. Meta-regression and subgroup analyses were performed to explore the sources of heterogeneity. Comparisons were made between individuals with and without malnutrition according to pulmonary function, degree of dyspnea, exercise capacity, and mortality risk.Out of the 4156 references identified, 101 were read full-text, of which 36 studies were included. The total number of involved patients included in this meta-analysis was 5289. The prevalence of malnutrition was 30.0% (95% CI 20.3 to 40.6), compared with an at-risk prevalence of 50.0% (95% CI 40.8 to 59.2). Both prevalences were associated with regions and measurement tools. The prevalence of malnutrition was associated with COPD phase (acute exacerbations and stable). COPD with malnutrition showed lower forced expiratory volume 1 s % predicted (mean difference (MD) -7.19, 95% CI -11.86 to -2.52), higher modified Medical Research Council dyspnea scores (MD 0.38, 95% CI 0.12 to 0.64), poorer exercise tolerance (standardized mean difference -0.29, 95% CI -0.54 to -0.05), and higher mortality risk (hazard ratio 2.24, 95% CI 1.23 to 4.06) compared to COPD without malnutrition.Malnutrition and at-risk for malnutrition are common among COPD. Malnutrition negatively impacts important clinical outcomes of COPD.