Lecture Notes, Biology 203, Human Sexuality and Reproduction

Hormones, Part 2

  1. Hormones in Older Adults
    1. Men
      1. By age 45, testosterone is being maintained at a lower level, with various consequences
      2. Decreased sperm count (not necessarily enough to make the man less fertile)
      3. Decreased sexual desire
      4. Decreased frequency of erections/ejaculations
      5. Decreased sexual performance
      6. Men may become alarmed or depressed, but can continue to have an active sex life if they (and their sexual partners) can be patient with themselves
      7. For severe cases, psychological counseling may help, occasionally testosterone treatment may be helpful
    2. Women
      1. After age 30-35, set point for maximum monthly estrogen level starts to fall
      2. Between ages 42 and 55 (average 50), the aging ovary stops responding to LH/FSH from pituitary, resulting in menopause (cessation of menstruation)
      3. Resulting decrease in E production prevents negative feedback from suppressing LH/FSH levels, so levels of LH/FSH rise in perimenopausal women
      4. Decrease in E is responsible for most of the symptoms associated with menopause
      5. Reversal of some sexual characteristics occurs (body shape, changes in breasts, hips, fat distribution, decreased vaginal lubrication)
      6. Changes in regulation of circulatory system may result in hot flashes, night sweats, headaches
      7. Decrease in E also decreases level of HDL and allows LDL to rise, increasing risk of cardiovascular disease
      8. Decrease in E increases likelihood of osteoporosis
        1. E enhances ability to use calcium, so when E level falls, bones may lose calcium, become brittle and easily broken
        2. In smokers, decrease in E occurs sooner, so earlier decrease in calcium absorption
      9. Hormone replacement therapy (includes both E and P to avoid slight increase in risk of uterine cancer if E is given alone)
        1. Reduces risk of heart attack, stroke, Alzheimer's in some studies, but not in others
        2. No increase in risk of breast cancer until woman has had more than 10 years of HRT
        3. Slight increase in breast cancer at that point suggests that women who have family history of breast cancer should not continue HRT for that long