Association Between Anthropometric Indices and Skeletal-Muscle Atrophy in Chinese Patients with Stable Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

Abstract

Purpose

Anthropometric indices are simple indicators of patient nutritional status. However, the association between these indices and skeletal-muscle atrophy in patients with stable chronic obstructive pulmonary disease (COPD) has not been fully investigated. In this study, we evaluated this association.

Patients and Methods

We recruited 123 outpatients with stable COPD from a general hospital in China from 2020 to 2021. We recorded their demographic characteristics, including age, sex, course of illness, dyspnea score, body mass index (BMI), force expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), smoking status, and severity grading. In addition, patients’ anthropometric indices, including fat-free mass index (FFMI) and appendicular skeletal-muscle mass index (ASMI), were measured using a body composition analyzer, and measurements were taken of the triceps skinfold (TSF), midarm circumference (MAC), and calf circumference (CC). We drew and analyzed a receiver operating characteristic (ROC) curve to identify the best intercept point value for the assessment of skeletal-muscle atrophy.

Results

The TSF, MAC, CC, FFMI, and ASMI of COPD patients were 1.08 ± 0.44 cm, 26.39 ± 2.92 cm, 34.5 ± 3.06 cm, 17.49 ± 1.86 kg/m², and 8.17 ± 0.90 kg/m², respectively. These anthropometric indices had a significant positive correlation with skeletal-muscle mass (correlation values, 0.481–0.820). CC was strongly correlated with both FFMI and ASMI. The ROC curve showed an area-under-the-curve (AUC) value of 0.873–0.959.

Conclusion

Anthropometric indices were correlated with skeletal-muscle mass. CC showed the best diagnostic value in COPD patients, suggesting its effectiveness as a simple method for assessing skeletal-muscle atrophy and identifying patients with a noticeable reduction in muscle mass. Such patients require early, multidisciplinary intervention.

Keywords:

• fat-free mass
• skeletal-muscle mass
• chronic obstructive pulmonary disease
• anthropometric index
• muscle atrophy

Abbreviations

COPD, chronic obstructive pulmonary disease; BMI, body mass index; FEV₁, forced expiratory volume in 1s; FVC, forced vital capacity; FFM, fat-free mass; FFMI, fat-free mass index; ASM, appendicular skeletal-muscle mass; ASMI, appendicular skeletal-muscle mass index; TSF, triceps skinfold; MAC, midarm circumference; CC, calf circumference; MAMC, midarm muscle circumference; MAMA, midarm muscle area; MMRC, modified Medical Research Council scale; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ROC, receiver operating characteristic; AUC, area under the curve.

Data-Sharing Statement

Researchers may make reasonable requests of the corresponding author for datasets used in this study.

Ethical Approval

The study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Soochow University, Suzhou, China. All patients provided written informed consent.

Consent to Publication

All authors agree to the publication of this study.

Acknowledgments

We thank LetPub for its linguistic assistance during the preparation of this manuscript.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This study was supported by the Suzhou Livelihood Science and Technology Project Fund (No. SYS 2020110), Natural Science Foundation of the First Affiliated Hospital of Soochow University (No. BXQN202116), National Natural Science Foundation of China (No.72204182) and the Nursing Society Talents “Seedling” Project Fund (No. SHQM202101).