Background and Aim
It is known that the variability of testosterone concentrations is predictive of both truncal and peripheral obesity in healthy men. The aim of this study was to establish the nature of the relationship between testosterone and fat mass in young male cancer survivors compared with healthy controls.
176 male cancer survivors (mean age 37.3 years SD 5.8) who previously received gonadotoxic therapy and were more than 2 years since end of treatment, and 213 controls (mean age 36.3 years, SD 6.8) with no previous history of cancer were recruited.
Total testosterone (tT) was measured from serum using ECLIA immunoassay (Roche). Truncal fat mass (TFM) was determined by dual energy x-ray absorptiometry. The study was approved by the local ethics committee and all subjects gave written informed consent.
tT was significantly lower (16.1 vs 18.8 nmol/L, P<0.001) and TFM was significantly higher (14.5 vs 12.2 kg, P<0.001) in cancer survivors compared with controls. Simple correlational analysis suggested a significant negative correlation between tT and TFM (R=−0.43, P<0.001). Further analysis suggested a linear relationship between the two was most appropriate for the data. After allowing for TFM there was still a significant association between the levels of tT with the group of cancer survivors having approximately 1.9 nmol/L lower levels of tT than controls (P=0.001, CI −2.9 to −0.8) for any level of TFM.
We have observed an increase in TFM and a decrease in total tT in the cancer survivors. Survivors have increased TFM and this is only partly explained by the decrease in total testosterone. There may be other factors that might explain the increase in TFM.
06 - 07 Nov 2006
Society for Endocrinology