Reevaluating Calf Circumference as an Indicator of Muscle Mass in Malnutrition Among Community-Dwelling Older Adults: A Cross-Sectional Analysis

Aim: The present study aimed to evaluate the agreement between calf circumference (CC) and dual-energy X-ray absorptiometry (DEXA) in assessing muscle mass, and to determine how possible discrepancies influence the diagnosis of malnutrition and its relationship with frailty and disability in older adults. Methods: We analyzed cross-sectional data from 1048 adults aged 65 years and older who participated in the 2001–2002 National Health and Nutrition Examination Survey (NHANES). Malnutrition was defined using the Global Leadership Initiative on Malnutrition (GLIM) criteria, and muscle mass was estimated using both DEXA and CC. Agreement between the two assessment methods was tested with Kappa statistics, while multivariable logistic regression models were used to explore the associations between malnutrition (as determined by each method) and frailty or disability, controlling for age, sex, physical activity, polypharmacy, and urinary albumin levels. Results: CC and DEXA-based appendicular skeletal muscle mass (ASM) showed a moderate correlation (r = 0.592). The prevalence of malnutrition was 10.3% when defined by CC and 9.1% when defined by DEXA (κ = 0.635, p = 0.001). In both cases, malnutrition was significantly associated with frailty (OR: 1.56; 95% CI: 1.240, 1.970, p < 0.001), but not with disability. Adjusting for albumin levels did not substantially change these associations. Conclusions: CC and DEXA demonstrate moderate concordance in estimating ASM. While this level of agreement slightly affects malnutrition prevalence estimates, it does not alter the observed relationship between malnutrition and frailty or disability in older adults.