The predictive capacity of adductor pollicis muscle thickness for physical frailty in older adults.

Purpose: There is a need for an easily measurable and reliable surrogate marker for physical frailty. This study aims to investigate the predictive capacity of adductor pollicis muscle thickness (AMPT), which can be easily measured externally and minimally influenced by subcutaneous adipose tissue, for physical frailty.

Methods: A total of 589 patients (16.3% physically frail, 54.7% pre-frail, 29% robust) were included. Comprehensive geriatric assessments and anthropometric measurements of the patients were performed. APMT was assessed with a skinfold caliper. Physical frailty was diagnosed using the fried frailty phenotype. The predictive ability of APMT for the diagnosis of frailty was examined.

Results: Of all the participants, 64.3% were women, and the average age was 74 ± 5.9 years. There was no significant difference in waist and hip circumference, or body mass index between the frail and non-frail groups. APMT, handgrip strength, gait speed, and calf circumference were significantly lower in frail patients than in non-frail ones (p < 0.01). The area under the curve (AUC) of APMT for physical frailty was determined to be 0.627 (95% confidence interval [CI] 0.58-0.66; p < 0.001). The best cut-off value for APMT was ≤ 18.5 mm for all individuals.

Conclusion: Adductor pollicis muscle thickness can be a useful anthropometric marker for evaluating the risk of physical frailty.