Objective: The aim of this study was to evaluate the association between serum levels of testosterone and free testosterone to lifestyle in aging males.
Methods: Men between 45 and 85 years were assessed regarding body mass index (BMI), nicotine and alcohol consumption, stress level, physical and social activity, and sleeping quality by a self-administered questionnaire. In parallel, serum levels of testosterone (T), free testosterone (fT), LH, FSH, DHEA-S, E2 and SHBG were obtained.
Results: In total, 375 men with a mean age of 59.9 years (9.2 +/- SD) entered this study; 25.4% and 27.4% had hypogonadal testosterone or free testosterone serum levels, respectively. Nicotine consumption (smokers had higher levels of T and fT; p < 0.01), BMI (negative correlation to T; p < 0.01) and age (negative correlation to fT; p < 0.001) correlated with serum levels of testosterone or free testosterone. Physical and social activity, nicotine and alcohol consumption, stress level and sleep quality did not show a significant association with serum androgen levels.
Conclusion: This prospective study of 375 men aged 45 to 85 years confirms the correlation between age, BMI and smoking with serum levels of testosterone and free testosterone, whereas the investigated variety of lifestyle factors did not show a significant association to serum androgen levels.