Finally, since synergic and/or antagonistic interactions between testosterone and insulin exist, by comparing plasma metabolisms recorded in IS and IR hypogonadism patients before testosterone restoration (where testosterone is low in both sets of patients and insulin function in the one case is normal while the other is characterized by insulin resistance) and after testosterone restoration (where testosterone is normal in both but insulin functions are different), interesting information can be obtained on the contributions of the two hormones, both separately and together. This evidence concerns the gene INS and hypogonadism.