Table 1. Characteristics and variables of the 1999 men who conformed well this study.

Variable	Mean±SD
Age (year)	37.54±11.10
BMI (kg/m2)	23.30±3.35
Ferritina (ng/ml)	318.00 (221.40, 459.90)
Estradiol (pg/ml)	34.44±9.99
SHBGb (nM)	42.21±20.56
Total testosterone (ng/ml)	6.27±1.91
Free testosterone (nM)	0.42±0.12
Free testosterone index (%)	58.28±22.58

Ferritin^a: the data was shown by median and interquartile range;

SHBG^b: sex hormone-binding globulin.