Z-score of the log-transformed A Body Shape Index predicts low muscle mass in population with abdominal obesity: The U.S. and Korea National Health and Nutrition Examination Survey

PLoS One. 2020 Nov 24;15(11):e0242557. doi: 10.1371/journal.pone.0242557. eCollection 2020.


Background and objective: Sarcopenic obesity is associated with a higher risk of cardiometabolic disease and mortality than either sarcopenia or obesity alone. However, no study has investigated body shape indices for the assessment of sarcopenia in obese populations. Thus, this study aimed to evaluate the accuracy of body shape indices to assess sarcopenia in nationally representative populations with abdominal obesity.

Methods: Data from the U.S. National Health and Nutrition Examination Survey (U.S. NHANES) 1999-2006 and Korea NHANES (KNHANES) 2008-2011 were assessed. The association between Body Shape Index and sarcopenia was analyzed using a receiver operating characteristic curve. The Z-score of the log-transformed A Body Shape Index (LBSIZ) cut-off value was defined as that with the highest score of the Youden's index. Changes in odds ratios (OR) for sarcopenia were investigated using restricted cubic spline (RCS) plots.

Results: This study included 8,013 American and 4,859 Korean adults with abdominal obesity. The overall area under the curve (AUC) of LBSIZ for sarcopenia was 0.816 (95% CI: 0.794-0.838) in U.S. NHANES and 0.822 (95% CI: 0.799-0.844) in KNHANES, which was higher than that of the body roundness index, conicity index, and waist to height ratio (p with DeLong's test <0.001). The cut-off values for the LBSIZ were 1.05 (sensitivity, 88.0%; specificity, 81.5%) for American men, 0.45 (sensitivity, 77.1%; specificity, 70.6%) for American women, 1.15 (sensitivity, 77.5%; specificity, 77.1%) for Korean men and 0.95 (sensitivity, 74.3%; specificity, 69.3%) for Korean women in the development groups. Comparable results were verified in validation groups. The RCS plot indicated that ORs for sarcopenia rapidly increased with an increase in the LBSIZ cut-off value.

Conclusion: The increased LBSIZ could function as a reliable and cost-effective screening tool for assessing low muscle mass in populations with abdominal obesity.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Body Composition
  • Cross-Sectional Studies
  • Female
  • Health Surveys
  • Humans
  • Male
  • Mass Screening / economics
  • Mass Screening / methods
  • Middle Aged
  • Muscle, Skeletal / pathology*
  • Nutrition Surveys
  • Obesity, Abdominal / complications*
  • Obesity, Abdominal / epidemiology
  • Obesity, Abdominal / pathology
  • Organ Size
  • Republic of Korea / epidemiology
  • Sarcopenia / epidemiology
  • Sarcopenia / etiology*
  • Sarcopenia / pathology
  • Sensitivity and Specificity
  • Statistical Distributions*
  • United States / epidemiology
  • Waist Circumference

Grant support

HSC HURF-2018-15 Hallym University Research Fund 2018 The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.