The following is a summary of “Differential impacts between fat mass index and fat-free mass index on patients with COPD,” published in the June 2023 issue of Pulmonology by Shimada, et al.
The impact of fat mass index (FMI) and fat-free mass index (FFMI) on clinical outcomes in patients with chronic obstructive pulmonary disease (COPD) needs to be better understood. For a study, researchers sought to investigate the differential effects of FMI and FFMI on emphysema, pulmonary function, and health-related quality of life in COPD patients.
A total of 228 COPD patients enrolled in a multicenter prospective 3-year cohort study were categorized into four groups based on median baseline FMI and FFMI values. Emphysema, assessed by the ratio of low attenuation area to total lung volume (LAA%) on computed tomography, pulmonary function, and health-related quality of life measured using the St. George’s Respiratory Questionnaire (SGRQ), were compared among the groups.
The four groups observed Significant differences in LAA%, pulmonary function, and SGRQ scores. The Low FMI Low FFMI group had the highest LAA%, lowest pulmonary function, and worst SGRQ scores compared to the other groups. The differences were consistent over the 3-year study period. Multivariate analysis revealed that low FMI was associated with high LAA%, low inspiratory capacity/total lung capacity (IC/TLC), and carbon monoxide transfer coefficient (KCO). On the other hand, low FFMI was associated with these factors and worse SGRQ scores.
FMI and FFMI have distinct effects on the clinical manifestations of COPD. Low fat and low muscle mass contribute to severe emphysema, while only low muscle mass is associated with worse health-related quality of life in COPD patients. The findings highlighted the importance of FMI and FFMI in managing and evaluating COPD patients.