Hormone blockade therapy for prostate cancer entails risks of diabetes and cardiovascular disease

A recent FDA MedWatch announcement alerts doctors to the increased risk of diabetes, heart attacks and strokes for patients with prostate cancer undergoing hormone blockade therapy, specifically treatment with Gonadotropin-Releasing Hormone (GnRH) agonists such as Lupron.

"Gonadotropin-Releasing Hormone (GnRH) agonists will have new safety information added to the Warnings and Precautions section of the drug labels. This new information warns about increased risk of diabetes and certain cardiovascular diseases (heart attack, sudden cardiac death, stroke) in men receiving these medications for the treatment of prostate cancer."

The normal action of gonadotropin-releasing hormone is to stimulate the secretion of the gonadotropins LH (luteinizing hormone) and FSH (follicle stimulating hormone) from the pituitary. These hormones in turn stimulate the production of testosterone and sperm by the testes. The GnRH agonists flood the pituitary receptors causing an inhibition of gonadotropin secretion in the same way that over-stimulation of any hormone receptor suppresses the system (as occurs with topical hormone replacement, insulin resistance, etc.) Incidentally the FDA also notes:

"The benefits of GnRH agonist use for earlier stages of prostate cancer that have not spread (non-metastatic prostate cancer) have not been established."

I have personally seen how GnRH agonists exacerbate tendencies for metabolic syndrome and cardiovascular disease and appreciate the seriousness of their advice to practitioners:

"Healthcare professionals should evaluate patients for risk factors for these diseases and carefully weigh the benefits and risks of using GnRH agonists before determining appropriate treatment for prostate cancer. Patients who are receiving treatment with GnRH agonists should undergo periodic monitoring of blood glucose and/or glycosylated hemoglobin (HbA1c). Healthcare professionals should also monitor patients for signs and symptoms suggestive of development of cardiovascular disease and manage according to current clinical practice."