Testosterone Effects
Testosterone:
- In puberty helps a boy in growth of the penis and testes, growth of facial and pubic hair, deepening of the voice, increase in muscle mass and strength, and increase in height.
- In adult man maintains sex drive, sperm production, male hair patterns, muscle mass, and bone mass
- Lowers blood sugar
- Increases bone mineral density in elderly men (1)
Testosterone Conversion
Testosterone converts to (5, page 24):
- Dihidrotestosterone (in testis, liver, brain, prostate, external genitalia)
- Androsterone
- Androstenedione
- Estradiol (in testis, liver, brain)
- Glucuronide
- Etiocholonolone
What Affects Steroid Production?
Below is the scheme of synthesis of steroid hormones (click image to enlarge it).
Substances and enzymes affecting steroidogenesis (5):
- Hydrogene peroxide (H2O2) (blocks conversion of pregnenolone to progesterone)
- Nitrous oxide (NO) (blocks steroid production)
- StAR (Steroid Acute Regulator) gene codes StAR protein that transfer cholesterol into mitochondria. Growth hormone, estradiol, calcium, and IGF-1 upregulate StAR gene, thus enhancing steroid production.
- Enzyme P450SCC converts cholesterol into pregnenolone (in mitochondria)
- Enzyme 3ßHSD converts pregnenolone to progesterone, and DHEA to androstenedione (3ß-HSD is stimulated by FSH, via LH)
- 5? reductase converts testosterone to dihydrotestosterone (DHT)
- Aromatase converts testosterone to estradiol
- Substances affecting steroidogenesis (5, pages 34-35)
- Dioxine (fatty meats, dairy) > low testosterone, and limited prostate growth
- Aminoglutethimide > low testosterone
- Lead, cadmium > low testosterone
What Affects Testosterone Blood Levels?
The following (1):
- Gonadotropin Releasing Hormone (GnRH) from hypothalamus stimulates secretion of LH
- LH from pituitary gland stimulates secretion of testosteron from testes
- Testosterone suppresses the release of GnRH from the hypothalamus (negative feedback)
- Low testosterone production:
- Chronic illness
- Delayed puberty
- Hypopituitarism
- Prolactinoma
- Testicular failure
- Steroid Hormone Binding Protein (SHGB) binds testosterone in blood. Increased SHGB lowers free testosterone in blood.
- Obesity – enzyme aromatase in fat tissue converts testosterone in estradiol thus lowering testosterone
- Zinc increases testosterone level
- A bioflavonoid called chrysin (in honey) has shown potential as a natural aromatase inhibitor. The Life Extension Foundation has identified a novel supplement called piperine that increases the bioavailability of chrysin
- Carnitine
- Muira puama
- Quercetin in red wine inhibits aromatase thus elevating testosterone
- Antioxidants (vitamin A, and E, zinc, and selenium) all support testosterone production
Low Testosterone (Androgen Deficiency)
Symptoms of low testosterone (2,3):
- Decreased sex drive (libido)
- Inadequate erections
- Increased breast size and tenderness
- Afternoon fatigue
- Symptoms similar to menopause in women (e.g., hot flashes, increased irritability, inability to concentrate, depression)
- SEVERE ANDROGENE DEFICIENCY:
- Loss of body hair
- Loss of muscle mass
- Fragile bones
- Smal and soft testes
Lab Results in Low Testosterone (4)
- Decreased bone density by dexa scan
- Loss in height of more than 1 inch.
- High blood pressure and heart enlargement with associated chest pain
- Increase in abdominal girth with 40” as maximum for men and waist size of in excess of 34 inches in women
- Low Free Testosterone, occasionally low total testosterone, and low normal bioavailable testosterone
- Loss of penile reflexes and decreased penis sensitivity
- Lowered sperm count and fertility
- Insulin resistance
- High blood glucose
- Below normal HDL
- Low SHBG
References:
- Testosterone increases bone density in elderly men (lef.org)
- Symptoms of low testosterone (hormone.org)
- Symptoms in severely lowered testosterone (nlm.nih.gov/medlineplus)
- Lab results in low testosterone (wellnessmd.com)
- Steroidogenesis of sex hormones (epa.gov/endo)
Tags: blood sugar, low testosterone