Is Free Testosterone Concentration a Prognostic Factor of Survival in Chronic Renal Failure (CRF)?

BACKGROUND: Lowered testosterone level in CRF patients is associated with elevated risk of death due to cardiovascular reasons, and is influenced by many factors, including acid-base balance disorders. Aims: evaluation of testosterone concentration (TT) and free testosterone concentration (fT) in pre-dialysis and dialysis patients; assessment of TT and fT relationships with biochemical parameters; evaluation of prognostic importance of TT and fT in predicting patient survival. MATERIAL/METHODS: 4 groups of men: 14 – on hemodialysis (HD), 13 – on peritoneal dialysis (PD), 9 – with chronic renal failure (CRF) and 8 – healthy (CG), aged 56±17, 53±15, 68±12, 43±10 years, respectively. TT and biochemical parameters were measured; fT was calculated. RESULTS: The lowest TT and fT were observed in HD and CRF, the highest – in CG (p=0.035 for TT; p=0.007 for fT). fT in CRF and CG were different (p=0.031). TT and age was associated in HD (p=0.026). Age and fT was strongly associated in PD (p<0.001). After adjustment for age, TT was negatively associated with BMI (p=0.013) and fT was positively associated with HCO3 level (p=0.007). fT was lower in those who died during 5 years of observation than in survivors (p=0.009). We have found that, opposite to TT, fT appeared to be a better predictor of 5-year survival than age. After combining pH and HCO3 levels into a single variable – no acidosis, acidosis with HCO3 normal serum level, acidosis with low concentrations of HCO3 and adjustment for age and the study group – a trend toward the lowest values of free testosterone in decompensated acidosis was observed (p(trend)=0.027). Such a trend was not seen for testosterone concentrations (p(trend)=0.107). CONCLUSIONS: Total and free testosterone levels were lower in HD and pre-dialysis than in healthy patients. Free testosterone level may predict long-term survival better than age. Total and free testosterone levels are lower in metabolic acidosis and total and free testosterone levels were positively associated with HCO3 level.