Do DHEA sulfate and total testosterone commonly decline with age in men?

Age-related decreases in DHEAS and total testosterone are common population-level findings in men, but neither marker alone measures adrenal or testicular “reserve.” This distinction is especially relevant at age 50, when values can remain within broad reference ranges despite a gradual downward trajectory.

Clinical evidence

• DHEAS declines relatively steeply with age. In men aged 60–77 followed for 10–14 years, the adjusted mean decline was 4.0% annually; after accounting for regression to the mean, only 5% showed a true increase. Another cohort of 883 men followed for a mean 11.55 years likewise found substantial annual loss.
• Total testosterone declines more gradually on average, with longitudinal estimates of about 0.5–0.6% per year in EMAS, 0.9–1.3% in Australian cohorts, and approximately 1.6% within individuals in the Massachusetts Male Aging Study. These are averages, not expected rates for an individual.

Mechanistic and diagnostic interpretation

• Aging is associated with reduced Leydig-cell responsiveness to LH: healthy-men stimulation studies found progressively lower testosterone-response efficacy and sensitivity to pulsatile recombinant LH. SHBG also rises with age (1.42% per year in EMAS), complicating interpretation of total versus free testosterone.
• DHEAS is adrenal in origin, and a value markedly below the age- and sex-specific lower limit can support suspicion of primary adrenal insufficiency. Yet age-related DHEAS decline is substantial; diagnosis requires morning cortisol/ACTH assessment and, when indicated, ACTH stimulation.
• A low total testosterone can be consistent with reduced testicular function, but obesity, diabetes-related low SHBG, acute illness, and assay/diurnal variation may lower total testosterone without intrinsic loss of reserve.

Bottom line

• The age-related decline is well established; interpreting it as reduced adrenal or testicular reserve is plausible but not diagnostic. Clinically meaningful testosterone assessment requires compatible symptoms and two fasting early-morning low results, with free testosterone considered when SHBG may be altered.