The potential of body mass index-adjusted calf circumference as a proxy for low muscle mass in the global leadership initiative on malnutrition criteria.

BACKGROUND & AIMS: Reduced muscle mass is one of the diagnostic components for Global Leadership Initiative on Malnutrition (GLIM), with various assessment methods proposed. Calf circumference (CC), a representative anthropometric marker of skeletal muscle mass, is now recommended to adjustment based on body mass index (BMI). This study aimed to evaluate the validity and efficacy of BMI-adjusted CC in very older adults, compared with other methods of assessing muscle mass.

METHODS

This prospective cohort study included 284 patients aged 65 years and older who were admitted to the Department of Geriatric Medicine at the National Center for Geriatrics and Gerontology Hospital. Health indicators, including nutritional status, were assessed upon admission. Three months after discharge, a telephone survey was conducted to assess patients' living conditions and survival status. Skeletal muscle mass was estimated using a dual-energy X-ray absorptiometry (DXA); moreover, anthropometric measurements (unadjusted and BMI-adjusted CC) were used as markers of muscle mass. Logistic regression analysis was performed to examine the association between mortality and GLIM-based malnutrition, using each muscle mass assessment method.

RESULTS

The mean age of the patients was 86.2 ± 6.2 years, and 60.9 % were women. The prevalence of GLIM-based malnutrition ranged from 55.3 % to 58.8 % across the three methods used to assess reduced muscle mass. Three months after discharge, 244 patients were followed up, of whom 29 (11.9 %) died. Multivariate logistic regression analysis, adjusted for age, sex, and comorbidities, showed that all methods significantly predicted 3-month mortality, with odds ratios of 5.67, 5.44, and 4.90 for unadjusted CC, BMI-adjusted CC, and appendicular skeletal muscle mass index using DXA, respectively. The prevalence and survival-predictive ability were similar across all methods.

CONCLUSION

GLIM-based malnutrition, diagnosed using different methods for assessing muscle mass, similarly predicted 3-month mortality in patients admitted to an acute geriatric ward. These results suggest that BMI-adjusted CC are sufficient alternatives when technical measurements such as DXA are not feasible.