ABSTRACT
Introduction: With the average longevity in men and women, sexual health concerns have become more and more important and demands for help are far more common than in the past. The percentage of aging population is increasing also. A metabolic and hormonal change occurs in male during aging.The level of total, free and bioavailable testosterone decline with aging and it leads to decrease in sexual activities, metabolism and also the life quality.The aim of this initial study was the determination of free testosterone and bioavailable testosterone and it was the novelty of our study. Data obtained from our research can be used as basic information for hormone replacement therapy in late onset hypogonadism.Research goal: To study the free testosterone and bioavailable testosterone level in aging malesMaterials and Methods: This study is a part of study: “Androgen status of aging males” which was supported by Asian Research Center, Korean Foundation for Advanced Studies. The study was approved by IRB of MoH and written consent was obtained from all participants.Fasting blood samples were collected in the morning between 8.00-10.00 AM. We used commercial ELISA kits from Magiwel CoLtd (USA) for determining the total testosterone, sex hormone binding globulin levels. Bromcresol green method was used in determination of serum albumin level. Bioavailable and free testosterone were calculated by Alex Vermeulen, Lieve Verdonk and M. Kaufman’s formula, which was recommended by International Society for the Study of Aging Male.We studied 114 healthy males aged above 40 years old, all undergone the General and Urological examination.Result and discussion: The average age was 57.48±10.48 years in our study participants. In group of 40-49 years were 29% (n=33), in 50-59 age group 23% (n=26), in 60-69 age group 27% (n=38) and in age group over 70-s were 15% (n=17).Mean total testosterone was 6.04±1.83 ng/ml, in 40-49 age group it was 6.14±1.65 ng/ml, in 50-59 age group 6.04±2.36 ng/ml, in 60-69 age group 6.05±1.80 ng/ml, and over 70’s it was 5.85±1.43 ng/ml.Mean sex hormone binding globulin was 50.22±29.97 nmol/l, in 40-49 age group 37.60±23.03 nmol/l, in 50-59 age group 47.08±29.61 nmol/l, in 60-69 age group 57.24±33.91 nmol/l, and over 70’s it was 59.22±25.38 nmol/l.Mean albumin was 40.86±6.89 g/l, in 40-49 age group 44.55±5.93 g/l, in 50-59 age group 41.85±6.93 g/l, in 60-69 age group 38.92±6.85 g/l, and over 70’s was 36.55±4.77 g/l.Mean free testosterone was 0.112±0.064 ng/ml, in 40- 49 age group 0.124±0.058 ng/ml, in 50-59 age group0.114±0.077 ng/ml, in 60-69 age group 0.107±0.072 ng/ml, and over 70’s it was 0.097±0.044 ng/ml.Mean bioavailable testosterone was 2.53±1.48 ng/ ml, in 40-49 age group 2.76±1.37 ng/ml, in 50-59 age group 2.60±1.70 ng/ml, in 60-69 age group 2.51±1.56 ng/ml, and over 70’s it was 2.04±1.05 ng/ml.Conclusion:1. In our participants aged above 40 years old, the average mean of free testosterone was 0.112±0.066 ng/ml, free testosterone index was 16.95±11.82. Free testosterone had inverse correlation with aging (r=-0.168, p=0.03) and had peer decline among aging groups.2. The average mean of bioavailable testosterone was 2.53±1.48 ng/ml, and had age related inverse correlation (r=-0.169, p=0.037), which decline was deeper in men aged over 70 years.Key words:Aging, total, free, bioavailable testosterone,free testosterone index