Utility of Calf Circumference in Predicting Swallowing Penetration in Sarcopenic Older Adults: A FEES-Based Study

Abstract

This study investigated clinical and anthropometric parameters, including ultrasound-derived swallowing muscle measurements, for predicting clinically significant swallowing penetration in sarcopenic older adults. Eighty adults aged ≥ 65 years (50 sarcopenic, 30 controls) attending a university hospital geriatric clinic were enrolled. Exclusion criteria were major neurological disorders, malignancy, head and neck surgery/radiotherapy, advanced organ failure, severe COPD, and rheumatologic disease. All underwent comprehensive geriatric assessments, including frailty (Fried criteria), cognitive and nutritional screening, EAT-10, and ultrasound-based sarcopenia assessment. Sarcopenia was defined as low handgrip strength and low STAR index (anterior thigh muscle thickness/BMI) using national cut-offs. Swallowing-related muscle thickness (genioglossus, geniohyoid, tongue), geniohyoid area, and elevation were measured ultrasonographically. Sarcopenic patients consenting to fiberoptic endoscopic evaluation of swallowing (FEES) were assessed using the Penetration-Aspiration Scale (PAS); PAS ≥ 3 indicated clinically significant penetration. Participants' mean age was 75.86 ± 6.89 years. Sarcopenic individuals were older, predominantly male, with lower genioglossus and tongue thickness, higher frailty scores, lower MMSE, and greater prevalence of diabetes and coronary artery disease. Among sarcopenic patients, 20% exhibited significant penetration. These patients had smaller arm/calf circumferences, slower gait speed, and higher EAT-10 scores, but no significant differences in swallowing muscle measurements or cognitive and nutritional status. Multivariate analysis identified lower calf circumference as the sole independent predictor (OR: 0.772, 95% CI: 0.613-0.972, p = 0.027). A threshold ≤ 32 cm yielded an AUC of 0.733 (p = 0.025), with 70% sensitivity and 77.5% specificity. In sarcopenic older adults, calf circumference is an independent, non-invasive predictor of clinically significant swallowing penetration, outperforming ultrasound-based swallowing muscle metrics in aspiration risk screening.

Keywords: Calf circumference; Dysphagia; Older; Penetration; Sarcopenia; Swallowing.