Andropause

From their late 30's onwards, men may experience a gradual age related decline in testosterone levels (3,213,214,215). This is of the order of 1.5% per year, but can accelerate as ageing progresses (213,214,215):

Age Bands	Approximate % Men with Low Bio-available Testosterone (derived from ref. 215)
20-39	1
40-59	9
60-79	24
80+	40

This age related testosterone loss can be associated with all of the problems previously described, and its correction associated with all of the benefits.

The hormonal changes characteristic of andropause are:

Testosterone levels decline due to age related testicular and hypothalamic-pituitary deficits (213,215)
Oestrogen levels decline but less so than testosterone, thereby increasing the ratio of oestrogens to androgens (38,216,217)
Sex hormone binding globulin (SHBG) levels increase, thereby 'locking up' more testosterone, further reducing the bioactive fraction (214,215,216,218)

The free bioactive fraction of testosterone declines more than the total testosterone (214,215,216,218), so total testosterone can test 'normal' despite clear deficiency of the bioactive fraction (3,214). As measurements of free testosterone in serum are technically complex (31,219) and therefore expensive, men usually receive the cheaper and potentially misleading 'total' determination (3).

The free hormone fraction is accurately measured by salivary hormone testing. This method measures the free bioactive fraction that is able to enter cells, bind with receptors, and exert its effects (182,184). It is not confounded by alterations in binding proteins such as SHBG (182,189,191,193,194). Free testosterone is accepted as the best indicator of androgen deficiency (3,213), and the one that most closely correlates with clinical symptoms (3,219).

Compounding the andropausal decline in testosterone levels is an age related decline in DHEA (76). As DHEA may contribute significantly to the total androgen pool (73,74,75) this can exacerbate androgen reductions due to andropause (213).

Whilst DHEA declines with aging, cortisol rises or remains relatively constant, resulting in an elevated cortisol to DHEA ratio (220,221). The potential deleterious effects of this environment are discussed elsewhere and may include further negative impacts on testosterone levels.

Using Androbalance test kits you can measure the levels of these hormones accurately and conveniently, thereby assessing the potential impact of age related endocrine changes on your health.