Age-stratified patterns of sarcopenic traits: Evidence for a life-course screening strategy from young adulthood to old age

AIM: Recent guidelines (AWGS 2025) advocate for a life-course approach to muscle health, lowering the screening age and redefining physical performance as an outcome measure rather than a diagnostic criterion. This study investigates the prevalence and clinical correlates of discordant sarcopenic traits across diverse age strata in a cross-sectional Taiwanese adult cohort. METHODS: This single-center study analyzed 2991 Taiwanese adults aged ≥20 years using DXA and functional assessments. AWGS thresholds were applied as absolute benchmarks across all ages to identify early-onset phenotypes and discordant patterns. Regression and trend analyses evaluated patterns among sarcopenia components. RESULTS: A distinct, age-dependent difference in sarcopenia phenotypes was identified across strata. In those <50 with low muscle mass, the predominant pattern was low physical performance with preserved strength. A critical age-related trend occurred at ages 50-64, where strength deficits emerged significantly. Older groups progressed toward combined deficits in both strength and performance. CONCLUSIONS: Sarcopenic traits manifest as age-stratified phenotypes. High prevalence of low performance with preserved strength in younger adults justifies separating performance from core diagnostic algorithms. Strength deficits in middle-aged adults provide epidemiological support for lowering the screening age to 50. These findings suggest that future screening strategies may consider prioritizing performance screening in early adulthood and initiate targeted strength assessments from age 50.