Do lower DHEA-S and reduced free testosterone reduce anabolic signaling?

In aging men, the gradual decline of circulating androgens, specifically free testosterone and dehydroepiandrosterone sulfate (DHEA-S), marks a pivotal shift in endocrine health that directly impacts cellular vitality and physical function.

Mechanistic signaling pathways

• Decreased intracellular cascades: Lower levels of free testosterone and DHEA-S directly diminish the activation of androgen receptors (AR). This reduction downregulates downstream cellular anabolic cascades, specifically the Akt and mTORC1 pathways, shifting the cellular state toward catabolism.
• IGF-1 modulation: DHEA-S serves as an essential modulator of growth factors. Its decline is associated with reduced insulin-like growth factor 1 (IGF-1) signaling, which deprives skeletal muscle of a primary upstream driver of protein synthesis and cellular growth.
• Inflammatory signaling: The loss of the anti-inflammatory actions of testosterone and DHEA-S leads to elevated inflammatory signaling, characterized by increased levels of pro-inflammatory cytokines such as interleukin-6 (IL-6).

Clinical and physiological consequences

• Muscle maintenance: Diminished AR-mediated signaling impairs satellite cell activation, accelerating muscle protein breakdown and driving the onset of muscle atrophy and sarcopenia.
• Tissue repair and immune function: A declining DHEA-S level disrupts the critical cortisol-to-DHEA-S ratio, which delays systemic tissue regeneration and wound healing. Concurrently, elevated IL-6 and weakened anabolic pathways drive immunosenescence, reducing overall metabolic and physiological resilience.

Bottom line

• Age-related declines in free testosterone and DHEA-S compromise critical anabolic pathways (AR, Akt/mTORC1, and IGF-1) and elevate inflammatory markers (IL-6), directly driving muscle loss, impaired tissue regeneration, and reduced systemic resilience in aging men.