Men’s health clinics report that as many as 70 percent of men seeking treatment for sexual dysfunction have evidence of hyperinsulinemia, usually accompanied by increased belly fat. Two common types of sexual difficulties affect men. One is reduced interest in sex: the other is difficulty getting an erection despite normal desire. Hyperinsulinemia brings on both of these problems, often at the same time.
Low Testosterone, “Low T”
Normally men’s testicles produce enough testosterone to maintain sex drive into old age. Hyperinsulinemia lowers testosterone levels in men, which in addition to reducing vitality and physical performance reduces sex drive. Low T can be treated by taking measures to eliminate hyperinsulinemia–reducing the glycemic load of the diet and eliminating insulin resistance with exercise and weight loss. It can also be treated with medication that increases testosterone levels.
Problems with Testosterone Blood Tests
Medical labs can measure testosterone levels in the blood, but there’s a problem with these tests. Testosterone is transported through the bloodstream by a carrier protein called sex hormone binding protein (SHBG). Most of the testosterone in the blood is bound to SHBG and not free to do its work. It turns out that hyperinsulinemia lowers SHBG levels, which reduces the total amount of testosterone in the blood but not necessarily the amount that is free to act. This can make low T look worse than it actually is.
Diagnostic laboratories have ways of estimating the proportion of testosterone bound to SHBG and the amount that is free to act, but these are rough approximations. Bottom line: testosterone blood tests can be helpful but must be interpreted in context with symptoms of low T such as reduced sex drive, energy levels and physical performance–especially when accompanied by increased belly fat.
Erectile Dysfunction (“ED”)
The other sexual problem men often have as they age is erectile dysfunction, difficulty getting an erection despite a normal sex drive. Sexual stimulation normally causes the arteries to the penis to open up and increase blood flow. Hyperinsulinemia is linked to an inability of these blood vessels to open up enough to produce a normal erection. Eliminating hyperinsulinemia with lifestyle changes that reduce insulin levels often restores normal erections. ED can also be treated with medications such as Viagra, which act directly on arteries to increase blood flow.
