Salivary testosterone (Sal-T) can be used to diagnose androgen deficiency reliably in men with end-stage renal disease (ESRD), according to a Brazilian study.

Estela Cardoso, PhD, of the Endocrine Research Department at the University of Buenos Aires, and colleagues studied male ESRD patients, aged 20-60 years, on hemodialysis who complained of decreased libido. Researchers obtained simultaneous morning saliva and serum samples from each patient to measure testosterone. In addition, 112 eugonadic and 40 hypogonadic adult men with normal renal function served as controls.

Sal-T testing showed 100% sensitivity and specificity in differentiating patients with androgen deficiency (22%) from those with normal androgen levels (78%), investigators reported in Nephrology Dialysis Transplantation (2011;26:677-683). Sal-T and serum free testosterone (Free-T) levels did not differ either in the ESRD patients or in controls. Hypogonadism was hypergonadotrophic in 69% of the cases and hypogonadotropic in 31%.

Sal-T and all serum testosterone fractions (Free-T, total testosterone, and bioavailable testosterone) correlated negatively with age and years of dialysis.

Dr. Cardoso’s team reported that there was a constant and predictable correlation between salivary and serum free steroid concentrations, the diagnostic accuracy of Sal-T was similar to that of serum testosterone, and a single saliva sample was just as informative as a single serum sample.

“These data demonstrate the value of morning Sal-T testing as a non-invasive approach to screen androgen status in ESRD patients,” the authors concluded.