Protective effect of pharmacological castration on metabolic perturbations and cardiovascular disease in the hyperglycemic male ApoE:Ins2 mouse model.

BACKGROUND

Unlike in other mouse models of atherogenesis, it has recently been suggested that orchiectomy plays a role in accelerating atherosclerosis and inhibiting the progression of cardiovascular disease in the ApoE:Ins2 mouse model of hyperglycemia. Androgen-deprivation therapy (ADT) is a common treatment for prostate cancer, a population with high prevalence of cardiovascular disease and its risk factors. Our objectives were to test and further characterize the effects of pharmacological castration which is currently the acceptable modality to deliver ADT in the clinic.

METHODS

Male ApoE:Ins2 mice received one of three modes of ADT (gonadotropin-releasing hormone (GnRH)-antagonist (degarelix), GnRH-agonist (leuprolide), or bilateral orchiectomy) and were compared to corresponding untreated control mice (n = 9-13/group). Mice were followed for 5 months. Body weight, fasting blood glucose, glucose tolerance, serum C-peptide, leptin, and testosterone levels along with atherosclerotic aortic plaque size and characteristics were determined. In a separate experiment, the survival of mice, untreated and on ADT, was determined.

RESULTS

Castration was achieved for all three modes of ADT. However, degarelix-treated mice gained significantly less weight, had lower serum leptin levels and systolic blood pressure compared to orchiectomy and leuprolide-treated mice. ADT improved dysglycemia and atherosclerotic burden. GnRH-antagonist significantly improved survival compared to GnRH-agonist but not compared to orchiectomy.

CONCLUSIONS

Further characterization of the ApoE:Ins2 mouse model confirms that pharmacological ADT ameliorated metabolic syndrome and cardiovascular complications. Improved dysglycemia and atherosclerosis associated with increased survival which was longest after degarelix followed by orchiectomy.