Journal of Clinical Endocrinology & Metabolism, Vol 63, 1418-1420, Copyright © 1986 by Endocrine Society

ARTICLES

Decreased bioavailable testosterone in aging normal and impotent men

HR Nankin and JH Calkins

Tissue available (bioavailable) testosterone (T) includes circulating free T (FT) and albumin-bound T. A reasonable assessment of bioavailable T can be made by using 50% ammonium sulfate to precipitate sex hormone-binding globulin (SHBG)-bound T. The supernatant non-SHBG- bound T (non-SHBG-T) correlates well with physiological androgen activity. To assess bioavailable T in normal aging men, we analyzed serum samples from seven healthy aged men (65-83 yr old) and compared the results to samples from 13 young men (22-39 yr old). Mean serum T, FT, and LH concentrations were not significantly different in the 2 groups. However, the mean absolute non-SHBG-T level was significantly lower (P less than 0.005) in the older group. In a separate population of 20 impotent but otherwise healthy men (5 27-37 yr old, 10 48-64 yr old, and 5 66-69 yr old), the mean absolute non-SHBG-T concentration was lower in middle-aged (P less than .01) and elderly men (P less than 0.001) than in young men. The absolute FT was lower only in the elderly group (P less than 0.05), while mean LH and T levels were similar in all 3 age groups. These data suggest that serum concentrations of tissue available T are decreased in aged men and that non-SHBG-T measurement is a more sensitive indicator of this decrease than are serum T or serum FT measurements. These changes appear to begin by middle age.

This article has been cited by other articles:

				F. Giton, S. Urien, C. Born, J. Tichet, J. Guechot, J. Callebert, F. Bronsard, J. P. Raynaud, and J. Fiet Determination of Bioavailable Testosterone [Non Sex Hormone Binding Globulin (SHBG)-Bound Testosterone] in a Population of Healthy French Men: Influence of Androstenediol on Testosterone Binding to SHBG Clin. Chem., December 1, 2007; 53(12): 2160 - 2168. [Abstract] [Full Text] [PDF]

				P. Y. Liu, P. Y. Takahashi, P. D. Roebuck, A. Iranmanesh, and J. D. Veldhuis Aging in Healthy Men Impairs Recombinant Human Luteinizing Hormone (LH)-Stimulated Testosterone Secretion Monitored under a Two-Day Intravenous Pulsatile LH Clamp J. Clin. Endocrinol. Metab., October 1, 2005; 90(10): 5544 - 5550. [Abstract] [Full Text] [PDF]

				P. Y. Takahashi, P. Y. Liu, P. D. Roebuck, A. Iranmanesh, and J. D. Veldhuis Graded Inhibition of Pulsatile Luteinizing Hormone Secretion by a Selective Gonadotropin-Releasing Hormone (GnRH)-Receptor Antagonist in Healthy Men: Evidence That Age Attenuates Hypothalamic GnRH Outflow J. Clin. Endocrinol. Metab., May 1, 2005; 90(5): 2768 - 2774. [Abstract] [Full Text] [PDF]

				J. D. Veldhuis, N. J. D. Veldhuis, D. M. Keenan, and A. Iranmanesh Age diminishes the testicular steroidogenic response to repeated intravenous pulses of recombinant human LH during acute GnRH-receptor blockade in healthy men Am J Physiol Endocrinol Metab, April 1, 2005; 288(4): E775 - E781. [Abstract] [Full Text] [PDF]

				M. Christ-Crain, C. Meier, P. R. Huber, L. Zimmerli, and B. Mueller Value of Gonadotropin-Releasing Hormone Testing in the Differential Diagnosis of Androgen Deficiency in Elderly Men J. Clin. Endocrinol. Metab., March 1, 2005; 90(3): 1280 - 1286. [Abstract] [Full Text] [PDF]

				A. Matejuk, C. Hopke, A. A. Vandenbark, P. D. Hurn, and H. Offner Middle-Age Male Mice Have Increased Severity of Experimental Autoimmune Encephalomyelitis and Are Unresponsive to Testosterone Therapy J. Immunol., February 15, 2005; 174(4): 2387 - 2395. [Abstract] [Full Text] [PDF]

				S. R. Kimball, J. P. O'Malley, J. C. Anthony, S. J. Crozier, and L. S. Jefferson Assessment of biomarkers of protein anabolism in skeletal muscle during the life span of the rat: sarcopenia despite elevated protein synthesis Am J Physiol Endocrinol Metab, October 1, 2004; 287(4): E772 - E780. [Abstract] [Full Text] [PDF]

				A. M. Kenny, G. Fabregas, C. Song, B. Biskup, and S. Bellantonio Effects of Testosterone on Behavior, Depression, and Cognitive Function in Older Men With Mild Cognitive Loss J. Gerontol. A Biol. Sci. Med. Sci., January 1, 2004; 59(1): M75 - 78. [Abstract] [Full Text] [PDF]

				S. Bhasin Testosterone Supplementation for Aging-Associated Sarcopenia J. Gerontol. A Biol. Sci. Med. Sci., November 1, 2003; 58(11): M1002 - 1008. [Abstract] [Full Text] [PDF]

				K. Dillner, J. Kindblom, A. Flores-Morales, R. Shao, J. Tornell, G. Norstedt, and H. Wennbo Gene Expression Analysis of Prostate Hyperplasia in Mice Overexpressing the Prolactin Gene Specifically in the Prostate Endocrinology, November 1, 2003; 144(11): 4955 - 4966. [Abstract] [Full Text] [PDF]

				K. T. Brill, A. L. Weltman, A. Gentili, J. T. Patrie, D. A. Fryburg, J. B. Hanks, R. J. Urban, and J. D. Veldhuis Single and Combined Effects of Growth Hormone and Testosterone Administration on Measures of Body Composition, Physical Performance, Mood, Sexual Function, Bone Turnover, and Muscle Gene Expression in Healthy Older Men J. Clin. Endocrinol. Metab., December 1, 2002; 87(12): 5649 - 5657. [Abstract] [Full Text] [PDF]

				M. Iannuzzi-Sucich, K. M. Prestwood, and A. M. Kenny Prevalence of Sarcopenia and Predictors of Skeletal Muscle Mass in Healthy, Older Men and Women J. Gerontol. A Biol. Sci. Med. Sci., December 1, 2002; 57(12): M772 - 777. [Abstract] [Full Text] [PDF]

				B. Surawicz and S. R. Parikh Prevalence of male and female patterns of early ventricular repolarization in the normal ECG of males and females from childhood to old age J. Am. Coll. Cardiol., November 20, 2002; 40(10): 1870 - 1876. [Abstract] [Full Text] [PDF]

				A. M. Kenny, K. M. Prestwood, C. A. Gruman, G. Fabregas, B. Biskup, and G. Mansoor Effects of Transdermal Testosterone on Lipids and Vascular Reactivity in Older Men With Low Bioavailable Testosterone Levels J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2002; 57(7): M460 - 465. [Abstract] [Full Text]

				A. M. Kenny, S. Bellantonio, C. A. Gruman, R. D. Acosta, and K. M. Prestwood Effects of Transdermal Testosterone on Cognitive Function and Health Perception in Older Men With Low Bioavailable Testosterone Levels J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2002; 57(5): M321 - 325. [Abstract] [Full Text]

				A. M. Matsumoto Andropause: Clinical Implications of the Decline in Serum Testosterone Levels With Aging in Men J. Gerontol. A Biol. Sci. Med. Sci., February 1, 2002; 57(2): M76 - 99. [Full Text]

				R. Davies, C. Collier, M. Raymond, J. Heaton, and A. Clark Indirect Measurement of Bioavailable Testosterone with the Bayer Immuno 1 System Clin. Chem., February 1, 2002; 48(2): 388 - 390. [Full Text] [PDF]

				X. Xu, E. Kreye, C. B. Kuo, and A. M. Walker A Molecular Mimic of Phosphorylated Prolactin Markedly Reduced Tumor Incidence and Size When DU145 Human Prostate Cancer Cells Were Grown in Nude Mice Cancer Res., August 1, 2001; 61(16): 6098 - 6104. [Abstract] [Full Text] [PDF]

				D. M. Keenan and J. D. Veldhuis Hypothesis testing of the aging male gonadal axis via a biomathematical construct Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2001; 280(6): R1755 - R1771. [Abstract] [Full Text] [PDF]

				A. M. Kenny, K. M. Prestwood, C. A. Gruman, K. M. Marcello, and L. G. Raisz Effects of Transdermal Testosterone on Bone and Muscle in Older Men With Low Bioavailable Testosterone Levels J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2001; 56(5): 266M - 272. [Abstract] [Full Text]

				F. Van Coppenolle, C. Slomianny, F. Carpentier, X. Le Bourhis, A. Ahidouch, D. Croix, G. Legrand, E. Dewailly, S. Fournier, H. Cousse, et al. Effects of hyperprolactinemia on rat prostate growth: evidence of androgeno-dependence Am J Physiol Endocrinol Metab, January 1, 2001; 280(1): E120 - E129. [Abstract] [Full Text] [PDF]

				A. M. Kenny, K. M. Prestwood, K. M. Marcello, and L. G. Raisz Determinants of Bone Density in Healthy Older Men With Low Testosterone Levels J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2000; 55(9): 492M - 497. [Abstract] [Full Text]

				D. C Gould, R. Petty, and H. S Jacobs For and against: The male menopause---does it exist? • For • Against BMJ, March 25, 2000; 320(7238): 858 - 861. [Full Text]

				C. M. Webb, J. G. McNeill, C. S. Hayward, D. de Zeigler, and P. Collins Effects of Testosterone on Coronary Vasomotor Regulation in Men With Coronary Heart Disease Circulation, October 19, 1999; 100(16): 1690 - 1696. [Abstract] [Full Text] [PDF]

				W. J. Kraemer, K. Hakkinen, R. U. Newton, B. C. Nindl, J. S. Volek, M. McCormick, L. A. Gotshalk, S. E. Gordon, S. J. Fleck, W. W. Campbell, et al. Effects of heavy-resistance training on hormonal response patterns in younger vs. older men J Appl Physiol, September 1, 1999; 87(3): 982 - 992. [Abstract] [Full Text] [PDF]

				S. R. Plymate III. Which Testosterone Assay Should Be Used In Older Men?1 J. Clin. Endocrinol. Metab., October 1, 1998; 83(10): 3436a - 3438. [Full Text]

				W. Byrd, M. J. Bennett, B. R. Carr, Y. Dong, F. Wians, and W. Rainey Regulation of Biologically Active Dimeric Inhibin A and B From Infancy to Adulthood in the Male J. Clin. Endocrinol. Metab., August 1, 1998; 83(8): 2849 - 2854. [Abstract] [Full Text]

				I. Sinha-Hikim, S. Arver, G. Beall, R. Shen, M. Guerrero, F. Sattler, C. Shikuma, J. C. Nelson, B.-M. Landgren, N. A. Mazer, et al. The Use of a Sensitive Equilibrium Dialysis Method for the Measurement of Free Testosterone Levels in Healthy, Cycling Women and in Human Immunodeficiency Virus-Infected Women J. Clin. Endocrinol. Metab., April 1, 1998; 83(4): 1312 - 1318. [Abstract] [Full Text]

				R. R. Hajjar, F. E. Kaiser, and J. E. Morley Outcomes of Long-Term Testosterone Replacement in Older Hypogonadal Males: A Retrospective Analysis J. Clin. Endocrinol. Metab., November 1, 1997; 82(11): 3793 - 3796. [Abstract] [Full Text] [PDF]

				H. Wennbo, J. Kindblom, O. G. P. Isaksson, and J. Tornell Transgenic Mice Overexpressing the Prolactin Gene Develop Dramatic Enlargement of the Prostate Gland Endocrinology, October 1, 1997; 138(10): 4410 - 4415. [Abstract] [Full Text] [PDF]

				J. E. Morley, F. Kaiser, W. J. Raum, H. M. Perry III, J. F. Flood, J. Jensen, A. J. Silver, and E. Roberts Potentially predictive and manipulable blood serum correlates of aging in the healthy human male: Progressive decreases in bioavailable testosterone, dehydroepiandrosterone sulfate, and the ratio of insulin-like growth factor 1 to growth hormone PNAS, July 8, 1997; 94(14): 7537 - 7542. [Abstract] [Full Text] [PDF]

				R. Sih, J. E. Morley, F. E. Kaiser, H. M. Perry III, P. Patrick, and C. Ross Testosterone Replacement in Older Hypogonadal Men: A 12-Month Randomized Controlled Trial J. Clin. Endocrinol. Metab., June 1, 1997; 82(6): 1661 - 1667. [Abstract] [Full Text] [PDF]

				S. M. Pincus, T. Mulligan, A. Iranmanesh, S. Gheorghiu, M. Godschalk, and J. D. Veldhuis Older males secrete luteinizing hormone and testosterone more irregularly, and jointly more asynchronously, than younger males PNAS, November 26, 1996; 93(24): 14100 - 14105. [Abstract] [Full Text] [PDF]

				L. L. Jeppesen, H. S. Jorgensen, H. Nakayama, H. O. Raaschou, T. S. Olsen, and K. Winther Decreased Serum Testosterone in Men With Acute Ischemic Stroke Arterioscler. Thromb. Vasc. Biol., June 1, 1996; 16(6): 749 - 754. [Abstract] [Full Text]