Background: Increased in utero exposure to testosterone (T) has long-lasting consequences on development. A large body of literature suggests prenatal T exposure to influence psychological and biological parameters. Aging is associated with various changes in the hypothalamic–pituitary–adrenal axis and the hypothalamic–pituitary–gonadal axis. Measuring one of the balances of these endocrine axes, the cortisol–testosterone ratio (CTr), can be used as indicator of endocrine health. An imbalance of these two systems (increased C and lower T), can compromise sexual function.
Aim: Besides the assessment of the CTr and sexual function, we investigated the moderating effect of prenatal T exposure (i.e. digit-ratio) on the association of the CTr and sexual function in aging males.
Methods: All 236 healthy men were between 40 and 75 years. Participants provided saliva samples under standardized conditions at 08:00 AM. Digit-ratios were measured, using a digital caliper Micrometer. Sexual function was assessed using the subscale of the aging-male-symptom-scale.
Results: Analyses yielded a moderating effect of the digit ratio on the association between the CTr and sexual function for higher than average CTr.
Discussion: The results indicate an effect of prenatal testosterone exposure on the association of CTr and sexual function in middle aged and older men. Lower prenatal T (i.e. higher digit-ratio) and higher CTr (increased C and lower T) seem to be associated with decreased sexual function.
Implications: Balanced endocrine systems buffer an age-related deterioration of sexual function in middle aged and older men. Based on these functions, preventive interventions could be developed to keep the endocrine system in balance.