Evaluation of the Effects of Cigarette Smoking on Testosterone Levels in Adult Men

Abstract

Introduction Cigarette smoking is highly prevalent among men. Many studies have evaluated the effect of cigarette smoking on levels of male reproductive hormones; however, the findings still remain controversial. Aim To evaluate the influence of cigarette smoking on serum levels of total testosterone (TT), free testosterone (FT), bioavailable testosterone (BT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Methods A total of 255 men (90 smokers and 165 nonsmokers), aged 30 to 70 years, were investigated. Weight and height were obtained and body mass index (BMI) was calculated. Also, waist circumference and hip circumference were measured and waist-to-hip ratio was obtained. Fasting blood samples were drawn for determination of plasmatic glucose levels and serum levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), triglycerides, albumin, prolactin, TT, SHBG, LH, and FSH. The values of low-density lipoprotein cholesterol (LDL-c) were determined by Friedwald equation and the values of FT and BT were calculated from TT, SHBG, and albumin. Statistical significance was set at P ≤ 0.05. Main Outcome Measures The influence of smoking on levels of TT, FT, and BT. Results No significant difference was observed in the mean values of TT (P = 0.580), FT (P = 0.869), BT (P = 0.933), SHBG (P = 0.279), LH (P = 0.573), and FSH (P = 0.693) in the different levels of pack-years when compared to nonsmokers. Moreover, after multivariate logistic regression, no association between increased pack-years of smoking and increased odds ratio for occurrence of low hormones and SHBG levels was observed. Conclusion In this study, smokers and nonsmokers had similar mean values of androgens, gonadotropins and SHBG. However, it is necessary to standardize pack-years of smoking in order to elucidate the influence of cigarette smoking on sex hormone levels, as well as to minimize differences among studies and to confirm our results.

Cigarette smoking has a positive and independent effect on testosterone levels

“…It is believed that categorizing retrospectively calculated pack-years helps reduce potential misclassification biases. 23,39 Moreover, in order to evaluate the effect of tobacco on hormones, smokers were also classified according to the number of cigarettes smoked per day (1-10 and >10).…”

“…[11][12][13][14][15][16][17] It is believed that ~34.8% of men worldwide are in the habit of smoking 18 and there have been widespread concerns regarding the relationship between testosterone levels and smoking. However, the reported effects of smoking on testosterone levels in men are controversial, with some evidence even suggesting no association 15,[19][20][21][22][23][24] and others reporting higher 13,14,[25][26][27][28][29][30][31][32] or lower 33,34 levels of TT among smokers compared to nonsmokers. In these studies, we also found similarly conflicting reports with regard to correlations of smoking and FT (free testosterone) and sex hormonebinding globulin (SHBG).…”

“…In these studies, we also found similarly conflicting reports with regard to correlations of smoking and FT (free testosterone) and sex hormonebinding globulin (SHBG). 13,14,23,31 Such discrepancies may be attributed to differences among these studies such as study sample sizes, potential confounders used for adjustment and the methods employed for estimating tobacco exposure.…”

The Effect of Prenatal Exposure to Nicotine versus Thiocyanate on Pituitary-Testicular Axis of Juvenile Albino Rats: A Comparative Histological and Electron Microscopic Study

“…Moreover, it was reported that smoking has been associated with testicular degeneration, disorganization of the cytoarchitecture and decreased serum testosterone levels [39]. Arrest of spermatogenesis may probably occur as a consequence of reduction in serum testosterone.…”

Testosterone Replacement Therapy in Reversing “Andropause”: What Is the Proof-of-Principle?

“…161 However, many studies have evaluated the effect of cigarette smoking on levels of male reproductive hormones, and findings still remain controversial. [161][162][163][164] Coffee consumption and physical exercise increased levels of TT and SHBG. 154,160 Interestingly, with the aim to determine whether greater participation in healthier behaviors, (i.e., refraining from smoking, maintaining physical activity, avoiding excessive alcohol consumption, eating more fish and less meat, avoiding adding salt to food, having a BMI] < 25 kg/m 2 , and consuming reduced-fat milk or skimmed milk) predicted reduced risk of subsequent lower circulating T in older men, Yeap et al conducted a crosssectional analysis of a population-based follow-up study concerning 3,453 men aged 65-83 years.…”