PLOD1 and hypogonadism: Limitations of the present study include lack of the sex hormone binding globulin (SHBG) measurement, and therefore calculated free serum testosterone which may have resulted in fluctuation of serum testosterone and an underestimation of the prevalence of biochemical hypogonadism since measurement of SHBG has been highly recommended in men with HIV in addition to LH and TT due to the possible rise in serum SHBG in these patients [27,64].