Testosterone can help men with hypogonadism lose weight, keep it off

"Obesity is very common in men with testosterone deficiency (hypogonadism)," said lead study author Karim Haider, M.D., a urologist and andrologist in private practice in Bremerhaven, Germany. "Men with hypogonadism and obesity receiving long-term testosterone therapy achieved progressive and sustained weight loss, while untreated controls gained. The favorable decreases in weight and waist circumference may have contributed to the observed reductions in mortality and major cardiovascular events."

Haider and his colleagues are conducting an ongoing observational registry study of men with hypogonadism in one urological office. For this ten-year report, they followed 805 patients with hypogonadism who were, on average, in their late fifties to mid-sixties. The 462 (57.4 percent) patients with obesity were given the choice whether to be treated with long-term testosterone therapy (TTh) with testosterone undecanoate injections (TU) 1,000 mg every 12 weeks. Of these, 273 opted to receive testosterone, and the 189 who declined treatment served as controls.

Over 10 years, the testosterone-treated men lost 20.3 percent of their baseline weight (50.5 lb; 22.9 kg); their waist circumference dropped by 12.5 cm (4.9 in). BMI decreased by 7.3 kg/m2, and the waist-to-height ratio decreased by 0.07.

By contrast, the untreated men gained 3.9 percent of their baseline weight (3.2 kg; 7.1 lb), and their waist size increased by 4.6 cm (1.8 in). In this group, BMI increased by 0.9 kg/m2, and waist-to-height ratio increased by 0.03.

During this time, 12 (4.4 percent) men in the testosterone group died, while in the untreated control group, 57 deaths (30.2 percent), 47 myocardial infarctions (24.9 percent) and 44 strokes (23.3 percent) occurred.

"Our study found long-term testosterone therapy in men with hypogonadism and obesity resulted in significant improvement in measures of body size and composition," Haider said. "In addition, testosterone therapy was associated with a reduced risk of death, heart attack and stroke. This suggests testosterone levels should be measured in men with obesity, and testosterone therapy should be offered if indicated."