Those receiving the hormone will get it in the form of 1,000 milligrams of Bayer’s long-acting Nebido, sold as Reandron in Australia, on entering the trial, after six weeks, and every three months for about two years. Men with prostate cancer and cardiovascular conditions are ineligible for study, which is also being supported by Lilly, Sanofi and Becton Dickinson & Co.
Although diabetes and obesity are linked to testosterone deficiency, scientists don’t know what effect testosterone has on diabetes risk for men whose waning sensitivity to insulin makes them pre-diabetic.
Trial participants will be monitored for blood sugar, muscle strength, body composition, and their motivation to stick with a lifestyle program, Wittert said.
“It’s going to be big undertaking, but we will get an answer,” said the University of Sydney’s Handelsman, whose ANZAC Research Institute is one of six sites in Australia involved in the research. “No other study of that scale and ambition is underway anywhere in the world to my knowledge.”
Use of testosterone in older men for purported benefits is contentious, according to Andrology Australia, which recommends testosterone be used “judiciously”until the findings from large research trials are known.
Potential benefits beyond current guidelines must be weighed carefully against the risks, the University of Sydney’s Handelsman said. Hormone replacement therapy was used routinely for symptom relief in menopausal women for three decades before large-scale clinical data showed it increased heart attacks and strokes, he said.
Without proper research, the same mistakes could be made with testosterone, Handelsman said. “I suspect, unfortunately, we are sliding down that pathway,” he said.