Louisville Medicine Volume 67, Issue 2 | Page 30

MEN'S HEALTH MALE HYPOGONADISM AUTHOR Ganesh Rao, MD INTRODUCTION In male hypogonadism, the body does not produce adequate amounts of the male hor- mone testosterone. Testosterone plays an important role in masculine growth and de- velopment during and after puberty. Hypogo- nadism can lead to the absence of secondary sex characteristics, erectile dysfunction, loss of muscle mass, osteopenia, infertility and loss of cognitive functions. CLASSIFICATION Primary: Primary hypogonadism happens due to problems from within the testicles. The most common cause of primary hypogo- nadism is late-onset hypogonadism that occurs as a consequence of age. The other causes of primary hypogonadism include Klinefelter syndrome, undescended testicles, mumps, hemochromatosis, tes- ticular trauma and chemotherapy. Secondary: The causes of secondary hypogonadism include pituitary and hypothalamic disease, HIV/AIDS, medications such as opiates, radiation to the brain, brain surgery, trauma and brain tumors. 28 LOUISVILLE MEDICINE PATHOPHYSIOLOGY OF TESTOSTERONE AND HYPOGONADISM The hypothalamus releases gonadotrophin releasing hormones in a pulsatile fashion which stimulates the pituitary gland that in turn produces luteinizing hormone (LH) and follicle stimulating hormone (FSH). Luteinizing hormones acts upon the Leydig cells in the testicle to produce testosterone while the follicle stimulating hormone acts on the seminiferous tubules to promote spermato- genesis. Testosterone then slows the release of LH via a negative feedback mechanism slowing the production of testosterone. Testosterone production slows as a result of age. Approximately 20% of men in their 50s and increasing numbers of men suffer from hypogonadism as they age. SYMPTOMS The symptoms of hypogonadism are fatigue, sleepiness, erectile dysfunction, depression, anemia, weight gain and infertility. SIGNS On physical exam, the signs include testicular atrophy, gynecomastia and obesity.