ArticleAging clinical and experimental research2025
Compared to total serum testosterone, calculated free testosterone has a stronger association with lean mass, muscle strength, power, and physical function in older men.
Article in Aging clinical and experimental research, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
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Who cites it
2 citing papers in PubMed.
- Sex hormones and menopause hormone therapy predict muscle strength across the lifespan.Journal of applied physiology (Bethesda, Md. : 1985) · 2026Article
- Male fertility as an integral reflection of metabolic, endocrine, and musculoskeletal health.Rheumatology international · 2026Review
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Authors and funding
7 authors.
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Abstract
backgroundLow serum testosterone concentrations have been associated with low muscle mass and strength in older men. However, the existing literature is inconclusive.
aimTo investigate the differences in the relationship between total and calculated free serum testosterone and muscle status, in young vs. old men.
methodsBody mass index (BMI), fat percentage, appendicular lean mass (ALM), percentage ALM (ALM%), skeletal muscle index (SMI), handgrip strength (HGS), leg extension power (LEP) and 30-s sit-to-stand performance (30-s STS) were measured in 557 healthy Danish men (326 younger (≤ 65 years) and 231 older (> 65 years)) aged 23-92 years. Total serum testosterone, sex hormone binding globulin and albumin were measured (ELISA) and subsequently, calculated free testosterone and free testosterone index (FTI) were computed. A general linear model examined the relationship between testosterone and individual muscle parameters, with age group-interaction, while a pooled effect model examined the relationship between testosterone and a compound of all muscle parameters, adjusted for age, BMI and fat percentage.
resultsTotal testosterone was negatively associated with 30-s STS in younger men, and positively associated with LEP in older men. Calculated free testosterone was positively associated with LEP in younger and older men, as well as SMI, ALM%, HGS and 30-s STS in older men. Calculated Free testosterone and FTI, but not total testosterone, were positively associated with the muscle compound in older men.
conclusionThe present data indicates that calculated free testosterone, compared to total testosterone, is more closely linked to muscle status and physical performance in older men.
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