Evaluation of the effects of cigarette smoking on testosterone levels in adult men.
BACKGROUND
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.


OBJECTIVE
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 < or = 0.05.


METHODS
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.


CONCLUSIONS
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.
Halmenschlager
Graziele
G
Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil. Electronic address: grazihal@gmail.com.
Rossetto
Simone
S
Laboratório de Biomedicina, Instituto de Ciências da Saúde, Centro Universitário Feevale, Novo Hamburgo, RS, Brazil.
Lara
Gustavo Müller
GM
Laboratório de Biomedicina, Instituto de Ciências da Saúde, Centro Universitário Feevale, Novo Hamburgo, RS, Brazil.
Rhoden
Ernani Luis
EL
Conselho Nacional de Pesquisa (CNPq), Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil.
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D007172:Erectile Dysfunction / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D012907:Smoking / Q000453:epidemiology*; D013739:Testosterone / Q000097:blood / Q000172:deficiency*
D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone