Serum testosterone levels in Nigerian male marijuana and cigarette smokers.
The effects of marijuana and cigarette use on serum levels of testosterone, the principal androgen in man has been a matter of serious controversy; and there is a paucity of reports on the subject in Nigeria in West Africa south of Sahara. We therefore investigated the effects of the use of these substances on serum levels of testosterone in young adult Nigerian males. Serum testosterone was estimated using enzyme linked immunosorbent assay (ELISA) on micro plate format in 169 Nigerian males (ages 18 – 35); 55 of whom were marijuana smokers, 62 cigarette smokers and 52 age – matched never – smokers who served as controls. Results show a significantly decreased (p<0.05) serum testosterone in marijuana smokers (5.33± 2.8ng/ml) compared with controls (8.5±2.4ng/ml). The testosterone level of cigarette smokers (5.4±1.5ng/ml) was similar (p>0.05) to that of marijuana users but significantly lower than that of the control group. The Body Mass Index (BMI) of marijuana smokers (29.5±8.07kg/m2) was significantly higher (p<0.05) than that of cigarette smokers (22.8±2.08kg/m2) and non-smokers (23.2±2.39kg/m2) but no significant difference was observed between cigarette smokers and non-smokers. There was a strong positive relationship between serum testosterone levels and duration (r=0.63, p<0.05) as well as frequency (wraps/day), (r=0.48, p<0.05) of marijuana use. We conclude that smoking of marijuana or cigarette has depressive effects on serum testosterone concentration in males and that this could be a factor in male infertility and therefore, should not be ignored in the investigation of infertility in males, especially those presenting with borderline fertility potentials. The campaign against the use of these substances should be intensified by government and other relevant agencies.