[Changes of serum reproductive hormones with aging among healthy males in a community population of Hebei Province].

The levels of serum LH, SHBG, fT, Bio-T, TSI and fTI changed with aging in a gradientmanner in the old and middle-aged males, but no significant changes were observed in the level of serum tT. There were statistical differences in many parameters of serum reproductive hormones among different age groups or between township and rural males.