The impact of body mass index on mortality in COPD: an updated dose-response meta-analysis

• Published in: European respiratory review 2024-10, Vol.33 (174), p.230261
• Main Authors: Tenda, Eric Daniel, Henrina, Joshua, Setiadharma, Andry, Felix, Immanuel, Yulianti, Mira, Pitoyo, Ceva Wicaksono, Kho, Sze Shyang, Tay, Melvin Chee Kiang, Purnamasari, Dyah S, Soejono, Czeresna Heriawan, Setiati, Siti
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Body Mass Index; Cardiovascular Diseases - mortality; Cause of Death; Female; Humans; Lung - physiopathology; Male; Middle Aged; Obesity - mortality; Prognosis; Protective Factors; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - mortality; Pulmonary Disease, Chronic Obstructive - physiopathology; Reviews; Risk Assessment; Risk Factors; Thinness - diagnosis; Thinness - mortality
• ISSN: 0905-9180; 1600-0617; 1600-0617
• DOI: 10.1183/16000617.0261-2023

The obesity paradox is a well-established clinical conundrum in COPD patients. This study aimed to provide an updated analysis of the relationship between body mass index (BMI) and mortality in this population. A systematic search was conducted through Embase, PubMed, and Web of Science. International BMI cut-offs were employed to define underweight, overweight and obesity. The primary outcome was all-cause mortality, and the secondary outcome was respiratory and cardiovascular mortality. 120 studies encompassed a total of 1 053 272 patients. Underweight status was associated with an increased risk of mortality, while overweight and obesity were linked to a reduced risk of mortality. A nonlinear U-shaped relationship was observed between BMI and all-cause mortality, respiratory mortality and cardiovascular mortality. Notably, an inflection point was identified at BMI 28.75 kg·m (relative risk 0.83, 95% CI 0.80-0.86), 30.25 kg·m (relative risk 0.51, 95% CI 0.40-0.65) and 27.5 kg·m (relative risk 0.76, 95% CI 0.64-0.91) for all-cause, respiratory and cardiovascular mortality, respectively, and beyond which the protective effect began to diminish. This study augments the existing body of evidence by confirming a U-shaped relationship between BMI and mortality in COPD patients. It underscores the heightened influence of BMI on respiratory and cardiovascular mortality compared to all-cause mortality. The protective effect of BMI was lost when BMI values exceeded 35.25 kg·m , 35 kg·m and 31 kg·m for all-cause, respiratory and cardiovascular mortality, respectively.