Dublin: A new study
says that weight loss can help obese, middle-aged, pre-diabetic
males boost low testosterone levels by almost 50 percent.
"Doctors should first encourage overweight men with low
testosterone levels to try to lose weight through diet and
exercise before resorting to testosterone therapy to raise their
hormone levels," said study co-author Frances Hayes, professor at
St. Vincent's University Hospital, Dublin.
The now completed US study involved nearly 900 men with
prediabetes, with an average age of 54 years, also called impaired
glucose tolerance, who had participated in the Diabetes Prevention
Program. It showed that people at high risk of Type 2 diabetes
could delay or avoid developing the disease through weight loss.
Because overweight men are more likely to have low testosterone
levels, Hayes and her colleagues studied the effect of weight loss
on men's testosterone levels. They excluded men from the study who
had a known diagnosis of hypogonadism or were taking medications
that could interfere with testosterone levels, according to a St
Hypogonadism is a condition characterized by low testosterone
levels with symptoms of male hormone deficiency. Symptoms can
include reduced sex drive, poor erections, enlarged breasts and
low sperm counts.
The men were randomly assigned to receive one of three treatments:
293 men to lifestyle modification, 305 to the diabetes drug
metformin and 293 to inactive placebo pills. Lifestyle
modifications consisted of exercising for 150 minutes a week and
eating less fat and fewer calories.
The results showed that low testosterone levels are common in
overweight men with prediabetes, Hayes said. At the beginning of
the study, nearly one in four men had low testosterone levels.
With lifestyle modification, the prevalence of low testosterone
levels decreased from about 20 percent to 11 percent after one
year, a 46 percent decrease, the authors reported. The prevalence
of low testosterone was unchanged in the metformin group (24.8
versus 23.8 percent) and the placebo group (25.6 versus 24.6
Men in the lifestyle modification group lost an average of about
17 pounds (7.8 kilograms) over the one-year study, according to
the abstract. The increase in testosterone levels in that group
correlated with decreasing body weight and waist size.
"Losing weight not only reduces the risk of prediabetic men
progressing to diabetes but also appears to increase their body's
production of testosterone," Hayes said.
The results were presented on Monday at The Endocrine Society's
94th Annual Meeting in Houston, US.