DHEA-S

Beside cortisol your adrenal glands make a second hormone: DHEA, a building block from which your body can make testosterone and oestrogen in the tissues. Most of it is given a sulphate group in the adrenal gland itself, which keeps it in the blood longer and makes the value stable over the day. That is DHEA-S, and in men and women it is the hormone circulating in the blood in the largest amount. In women it is the main source of testosterone after the menopause; in men it delivers a small part beside the testicles. Production begins around age seven, peaks between the twenties and thirties and falls steadily after that, to about a fifth of the peak around seventy. That decline is the subject of most questions about DHEA-S, and it is ordinary: all labs lower their band with the years, and women sit lower than men at every age. A value that comes out above the band in a man at age 70 falls in the middle of the normal range in a man at age 30. Unlike cortisol, DHEA-S does not move with the hour, so the time of the draw matters little; prednisone and other steroids do lower it, because they shut down the brain's order to the adrenal gland. Your report shows DHEA-S in µmol/l, and the band belongs to your age and sex. Where the bands overlap it runs for a man at age 30 from 4.1 to 10.19 µmol/l, at age 50 from 1.9 to 8.4 µmol/l and at age 70 from 1.1 to 5.4 µmol/l; for a woman at age 30 from 1.6 to 6.2 µmol/l, at age 50 from 0.95 to 4.6 µmol/l and at age 70 from 1.7 to 2.4 µmol/l.

DHEA-S is the value that says where excess male hormone in a woman comes from. With excess hair growth, acne, an irregular cycle or hair loss on the head there are two sources: the ovaries, which mainly make testosterone, and the adrenal glands, which mainly make DHEA-S. A high DHEA-S points to the adrenal glands. In PCOS it is slightly raised in one in three women; a value far above the band, more than double, is rare and points to an adrenal gland making too much on its own, and that is investigated. The second reason is the distinction from cortisol. Both come from the same adrenal glands, but cortisol follows the clock and DHEA-S does not. Anyone who sees a deviating cortisol can read from DHEA-S whether the adrenal gland as a whole is involved: in Addison's both are low, with a course of prednisone too, and with a disturbed daily rhythm only cortisol is off. That makes DHEA-S the calm counterpart. The honest limitation is the decline with the years, which many people read as a deficiency. A lower DHEA-S with ageing goes with less muscle strength, bone density and wellbeing, but topping up with DHEA tablets has not reversed that in research in healthy older people, and in women it gives acne, oily skin and excess hair growth. It is a mirror of age, not a lever.

A low value is usually age, and the first question is which band you set it against. Every band falls with the years, so a value called low in someone of thirty is ordinary in someone of sixty. After that comes prednisone, also as an inhaler or ointment, which shuts down the brain's order to the adrenal gland and lowers DHEA-S together with cortisol; after stopping it recovers in weeks to months. Rare are adrenal glands that make too little, as in Addison's disease, and then cortisol is low too and there are symptoms of tiredness, nausea and low blood pressure. A low DHEA-S in a healthy body is not a finding and no reason to top up. A high value is first a question about the age you compare against, because the same value is normal in someone of twenty and high in someone of seventy. If the value is genuinely raised for your age, that points to the adrenal glands as a source of male hormone. In a woman with excess hair growth, acne or an irregular cycle a slightly raised value is usually PCOS, in which the ovaries and the adrenal glands both make slightly too much. A value far above the band, more than double the upper limit, is rare and fits an adrenal gland making too much on its own, and that is imaged. Always read DHEA-S against your age and sex, beside cortisol, which comes from the same adrenal glands but moves with the clock, and in a woman with symptoms of male hormone beside testosterone, which says whether the ovaries are involved, and oestradiol.