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A critical evaluation of simple methods for the estimation of free testosterone in serum.
The FT value, obtained by calculation from T and SHBG as determined by immunoassay, appears to be a rapid, simple, and reliable index of bioavailable T, comparable to AFTC and suitable for clinical routine, except in pregnancy. Expand
The decline of androgen levels in elderly men and its clinical and therapeutic implications.
Until the long-term risk-benefit ratio for androgen administration to elderly is established in adequately powered trials of longer duration, androgen administrations to elderly men should be reserved for the minority of elderly men who have both clear clinical symptoms of hypogonadism and frankly low serum testosterone levels. Expand
Influence of some biological indexes on sex hormone-binding globulin and androgen levels in aging or obese males.
The influence of age, smoking, body mass index (BMI), serum albumin, insulin, GH, and insulin-like growth factor I (IGF-I) levels, respectively, on androgen levels and SHBG-binding capacity in a nonobese healthy population as well as in an obese population before and after weight loss is investigated. Expand
Estradiol in elderly men
The role of estrogens in male physiology has become more evident, as a consequence of the discovery of human models of estrogen deficiency such as estrogen resistance or aromatase deficiency. InExpand
Bone mineral status in growth hormone-deficient males with isolated and multiple pituitary deficiencies of childhood onset.
The observations of a more pronounced bone mineral deficit at the forearm than at the lumbar spine and the findings of osteopenia in both the patients with isolated GH deficiency and multiple pituitary deficiencies support the view that GH deficiency per se is responsible for part of the observed deficit. Expand
The hormonal activity of the postmenopausal ovary.
  • A. Vermeulen
  • Medicine
  • The Journal of clinical endocrinology and…
  • 1 February 1976
It is concluded that the adrenal cortex is almost the exclusive source of plasma estradiol, estrone, progesterone, and 17OH progester one and the most important source of Plasma dehydroepiandrosterone and that hCG stimulation with 5000 IU daily for 3 days, hardly influences steroid secretion by postmenopausal ovaries. Expand
Pathogenesis of the decreased androgen levels in obese men.
Even in massively obese subjects with decreased FT levels, androgen metabolism and 5 alpha-reductase activity appeared to be normal, as suggested by similar androstanediol glucuronide and AG levels, determined by RIA or calculated from the conversion rates of precursors obtained in nonobese subjects. Expand
Ageing of the hypothalamo-pituitary-testicular axis in men.
Both spermatogenesis and fertility as well as Leydig cell function do decline with age, as shown by a decrease of +/- 35% of total and of 50% of free testosterone levels between the age of 20 and 80 years. Expand
Fat tissue: a steroid reservoir and site of steroid metabolism.
It is concluded that fat tissue is an important steroid hormone reservoir, that it is the site of active aromatase and 17 beta-hydroxysteroid dehydrogenase, and that tissue DHEA(S) may have a modulating effect on tissue estrogen production. Expand
Attenuated luteinizing hormone (LH) pulse amplitude but normal LH pulse frequency, and its relation to plasma androgens in hypogonadism of obese men.
The decreased LH pulse amplitude and the decreased amplitude of cortisol pulses, and hence probably of ACTH pulses, point toward a general alteration of hypothalamo-pituitary function in obese men. Expand