AbstractObjective: The aim of this study was to determine the age at which testosterone starts decreasing in male subjects. Methodology: This comparative study was conducted on two groups; group 1 included male subjects with 18–21 years of age and group 2 included male subjects with 22–25 years of age. Subjects having history of hypogonadism,hyperthyroidism, hypothyroidism, mental illness like depression were all excluded. Serum testosterone was analyzed by Radio-Immuno Assay method on gamma counter in Institute of Radiotherapy and Nuclear Medicine (IRNUM), Peshawar.The serum testosterone levels of the two groups were compared for a significant difference by using student-t test. Results: Group 1 included 80 subjects and group 2 had 75 patients. In group 1, testosterone level was >12 ng/ml in 22.5% (n=18/80), 7-12ng/ml in 58.75% (47/80) and <7 ng/ml in 18.75% (n=15/80) cases. In group 2, testosterone level was >12 ng/ml in 8% (n=6/75), 7-12ng/ml in 54.6% (n=41/75) and <7 ng/ml in 37.3% (n=28/75) cases. Mean testosterone level was 9.40±2.986 ng/ml in group 1 and 7.89±2.891 ng/ml in group 2 (p<0.05). Conclusion: The testosterone level in male subject is significantly lowered at 22–25 years of age as compared to 18–21 years of age. Well planned and large scale studies are required to address the issue in detail and to find out the causes of early decline of the testosterone level in young male subjects. Keywords: Testosterone, Aging, Hypogonadism, Optimal Health This article may be cited as: Rahman UU, Hamid N, Ubaidullah , Ahmad N, Safeer M, Tariq M, et al. The age at which testosterone starts decreasing in men now-a-days. Khyber Med Univ J 2012; 4(4): 174-178.
Life JS, Mintz AP. “A Second Confirmation for the Benefits
of HRT for Men.” Retrieved October 2012 from http://
Lo Y. Estimating Age-specific Prevalence of Testosterone
Deficiency in Men Using Normal Mixture Models. J Data
Science 2009; 7: 203-217.
Swerdloff RS, Wang C. The testis and male sexual function.
In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th
ed. Philadelphia, Pa: Saunders Elsevier; 2011: pp. 242.
Topiwala S. “Testosterone” Retrieved 22nd March, 2012
Nahoul K, Roger M. Age-related decline of plasma bioavailable testosterone in adult men. J Steroid Biochem
; 35(2): 293-9.
Okamura K, Ando F, Shimokata H. Serum total and free
testosterone level of Japanese men: A population-based
study. Int J Urol 2005; 12: 810-4.
Sternbach, H. Age-associated testosterone decline in
men: clinical issues for psychiatry. Am J Psychiatry
Wang X, Shen CL, Dyson MT, Eimerl S, Orly J, Hutson
JC, et al. Cyclooxygenase-2 regulation of the age-related
decline in testosterone biosynthesis. Endocrinology
; 146(10): 4202- 8.
Purifoy FE, Koopmans LH, Mayes DM. Age differences
in serum androgen levels in normal adult males. Hum
Biol 1981;53: 499–511.
Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman
MR. Baltimore Longitudinal Study of Aging. Longitudinal
effects of aging on serum total and free testosterone
levels in healthy men. J Clin Endocrinol Metab 2001;
Travison TG, Araujo AB, Kupelian V, O’Donnell AB,
McKinlay JB. The relative contributions of aging, health,
and lifestyle factors to serum testosterone decline in
men. J Clin Endocrinol Metab 2007; 92: 549-55.
Wu FC, Tajar A, Pye SR, Silman AJ, Finn JD, O’Neill TW,
et al. European Male Aging Study Group. Hypothalamic-
pituitary-testicular axis disruptions in older men are
differentially linked to age and modifiable risk factors. J
Clin Endocrinol Metab 2008; 93: 2737-45.
Shanti Med spa, Testosterone for Men: Optimal Health
Today. Retrieved November 2012 from http://optimalhealthtoday.
Jones GE, Baker K, Fahmy DR, Boyns AR, Leifke E. Effect
of luteinizing hormone releasing hormone on plasma
levels of luteinizing hormone, oestradiol and testosterone
in the male dog. J Endocrinol 1976; 68: 469-474.
Leifke E, Gorenoi V, Wichers C, Von Zur Mühlen A, Von
Büren E, Brabant G, et al. Age-related changes of serum
sex hormones, insulin-like growth factor-1 and sex-hormone
binding globulin levels in men: cross-sectional
data from a healthy male cohort. Clin Endocrinol (Oxf).
; 53: 689-9.
Marcell TJ, Harman SM, Urban RJ, Metz DD, Rodgers
BD, Blackman MR. Comparison of GH, IGF-I, and testosterone
with mRNA of receptors and myostatin in skeletal
muscle in older men. Am J Physiol Endocrinol Metab
; 281: 1159-64.
St. Louis, Is there a Male ‘Menopause? Retrieved from
December 7, 2012 http://www.usdoctor.com/testone.htm
Mazur A, Booth A. “Testosterone and dominance in
men.” Behavioral Brain Sci 1998; 21(3): 353-97.
Gapstur SM, Gann PH, Kopp P, Colangelo L, Longcope
C, Liu K. Serum androgen concentrations in young men:
a longitudinal analysis of association with age, obesity
and race. The Cardia Male Hormone Study. Cancer
Epidemiol Biomarkers Preven 2002; 11: 1041-7.
Field AE, Colditz GA, Willett WC, Longcope C, Mc-Kinlay
JB. The relation of smoking, age, relative weight and
dietary intake to serum adrenal steroids, sex hormones
and sex hormone-binding globulin in middle-aged men.
J Clin Endocrinol Metab 1994; 79:1310-16.
Wang XJ, Dyson MT, Mondillo C, Patrignani Z, Pignataro
O, Stocco DM. Interaction between arachidonic acid and
cAMP signaling pathways enhances steroidogenesis
and StAR gene expression in MA-10 Leydig tumor cells.
Mol Cell Endocrinol 2002; 188: 55–63.
Ronco AM, Moraga PF, Llanos MN. Arachidonic acid release
from rat Leydig cells: the involvement of G protein,
phospholipase A2 and regulation of cAMP production.
J Endocrinol 2002; 172: 95–104.
Wang X, Walsh LP, Reinhart AJ, Stocco DM. The role of
arachidonic acid in steroidogenesis and steroidogenic
acute regulatory (StAR) gene and protein expression. J
Biol Chem 2000; 275: 20204–9.
Wang XJ, Dyson MT, Jo Y, Eubank DW, Stocco DM. Involvement
of 5-lipoxygenase metabolites of arachidonic
acid in cyclic AMP-stimulated steroidogenesis and steroidogenic acute regulatory protein gene expression. J
Steroid Biochem Mol Biol 2003b; 85: 159–66.
Shea-Eaton W, Sandhoff TW, Lopez D, Hales DB, McLean
MP. Transcriptional repression of the rat steroidogenic
acute regulatory (StAR) protein gene by the AP-1 family
member c-Fos. Mol Cell Endocrinol 2002; 188: 161–70.
Stewart KG, Zhang Y, Davidge ST. Aging increases
PGHS- 2-dependent vasoconstriction in rat mesenteric
arteries. Hypertension 2000; 35: 1242–7.
Chung HY, Kim HJ, Kim JW, Yu BP. The inflammation
hypothesis of aging: molecular modulation by calorie
restriction. Ann NY Acad Sci 2001; 928: 327–35.
Syntin P, Chen H, Zirkin BR, Robaire B. Gene expression
in Brown Norway rat Leydig cells: effects of age and
of age-related germ cell loss. Endocrinol 2001; 142:
Wang XJ, Shen CL, Dyson MT, Hutson JC, Stocco DM.
c. Cyclooxygenase-2 and its inhibitors in StAR gene
expression and testosterone biosynthesis in aged male
rats. In: Proceedings of the Annual Healthy Aging Symposium:
Ages and Stages, Lubbock, Texas.
Wang XJ, Dyson MT, Jo Y, Stocco DM. Inhibition of cyclooxygenase 2 activity enhances steroidogenesis and
steroidogenic acute regulatory gene expression in MA-10
mouse Leydig cells. Endocrinol 2003a; 144: 3368–75.
Gao HB, Shan LX, Monder C, Handy MP. Supression
of endogenous corticosterone levels in vivo increases
the steroidogeneic capacity of purified rat Leidig cells
in vitro. Endocrinol 1996; 137: 1714–8.
Roy M, Kirschbaum C, Steptoe A. Intraindividual variation
in recent stress exposure as a moderator of cortisol and
testosterone levels. Ann Behav Med 2003; 26: 194–200.
Gao HB, Tong MH, Hu YQ, Guo QS, Ge R, Hardy MP.
Glucocolticoid induces apoptosis in rat Leidig cells.
Endocrinol 2002; 143: 130–8.
Midzaka AS, Chen H, Papadopoulos V, Zirkin BR. Leydig cell aging and the mechanisms of reduced testosterone
synthesis. Molecular and Cellular Endocrinology 2009;
Work published in KMUJ is licensed under a
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.