Ubaidur Rahman, Naila Hamid, Ubaid Ullah, Nisar Ahmad, Muhammad Safeer, Muhammad Tariq, Jamilur Rehman.
The age at which testosterone starts decreasing in men now-a-days.
Khyber Med Uni Med J Jan ;4(4):174-8.

Objective: 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.

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