High prevalence and interaction of hypogonadism and the metabolic syndrome in long-term survivors with germ cell tumours
M. Zitzmann, F. Gottardo, L. Grunwald, G. Pühse, A. Secker & S. Kliesch
Introduction and objectives: Testicular cancer survivors (TCS) are at a putative risk to develop premature testosterone deficiency (TD). The clinical and biochemical components of TD and the metabolic syndrome have not been thoroughly described in such patients.
Material and methods: Prospective clinical trial: 163 TCS took part in the study, clinical parameters, sex hormones and biochemical values were assessed in fasting blood samples, MS was defined according to the harmonized criteria of 2009 (IDF&NCEP). Intima-media thickness of carotid arteries was measured. Validated German Questionnaires of AMS scale and IIEF 15 were administered.
Results: Mean age at presentation was 40.3±8.4 years and median follow-up was 7 years. 102/163 pts. (62,6%) had received polychemotherapy, 49 (30%) radiotherapy. 15 pts. had undergone bilateral orchiectomy and are under T substitution, 24 pts. with unilateral tumour were at the time of the study already under T substitution. 39/163 pts. (23.9%) had a total T level of <12 nmol/l. 57/163 pts. (35.0%) fulfilled the criteria for the MS. In multivariate models, waist circumference, high triglyceride levels and decreased insulin sensitivity (QUICKI) were markedly associated with low testosterone levels (P=0.006, P=0.005 and P=0.002 respectively). TD was predictive for overall presence of MS (P=0.01) and the number of fulfilled criteria (P=0.01). Tumour characteristics and type of chemotherapy were not associated with a increased risk to develop TD.
Conclusions: Data confirm the high prevalence of TD and MS in long-term TCS. Pivotal clinical and biochemical components of TD as well as the MS are strongly exhibited in TCS. TCS should be closely monitored beyond a 10-years-follow-up-period and according to risk-prediction models encompassing pertinent markers for both clinical entities, TD and MS. This could help to identify patients who could benefit from an early T replacement, thus improving their quality of life and probably reducing their cardiovascular risk.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.