Predictive Value of Gluteal Muscle Index for Diagnosing Sarcopenia in Community-Dwelling Adults

Sarcopenia research has primarily focused on the diagnostic value of the psoas and paraspinal muscles due to their accessibility and reflection of the total skeletal muscle mass. This focus has overlooked the gluteal muscles, which are essential for mobility, balance, and prevention of falls, especially in elderly individuals. This prospective observational cohort study aimed to investigate the predictive value of the gluteal muscle index (GMI) for diagnosing sarcopenia in community-dwelling healthy adults.

The analysis included 290 community-dwelling healthy adults using health examination data. Sarcopenia was diagnosed using bioimpedance analysis. The psoas muscle index (PMI), paraspinal muscle index (PaMI), and GMI were measured via abdominal-pelvic computed tomography and adjusted for height. Additionally, body mass index, bone mineral density, and visceral and subcutaneous fat indices were analyzed.

Among the 290 patients, 26 (9.0%) were diagnosed with sarcopenia. GMI (48.6 ± 8.4 cm²/m² vs. 41.0 ± 7.9 cm²/m², p < 0.001), PaMI (14.5 ± 3.2 cm²/m² vs. 12.2 ± 3.3 cm²/m², p < 0.001), and PMI (5.7 ± 1.7 vs. 4.9 ± 1.6, p = 0.033) were significantly lower in the sarcopenia group. The receiver operating characteristic curves for GMI indicated an area under the curve of 0.872 for men and 0.811 for women, with cutoff values of 50.6 cm²/m² and 34.5 cm²/m², respectively.

The present study highlights the potential of GMI as a clinically meaningful predictor of sarcopenia, outperforming the psoas muscle in diagnostic accuracy. Furthermore, the sex-specific cutoff values identified from the study could aid in early detection and risk stratification, offering a novel approach for sarcopenia assessment in community-dwelling adults.