Testosterone alone is not a replacement for lifestyle changes in older men at risk of type 2 diabetes, new study shows

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by The Endocrine Society

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Testosterone treatment may improve body composition, glucose metabolism and sexual desire in some older men at high risk of type 2 diabetes (T2D), but the benefits require engagement in a lifestyle program, according to a study presented at ENDO 2026, the Endocrine Society's annual meeting in Chicago.

More than 40 million people in the U.S. and hundreds of millions worldwide have been diagnosed with T2D, and more than 115 million adults in the U.S. are estimated to have prediabetes. T2D is diagnosed most commonly in adults 45 and older. It is strongly linked to abdominal obesity and loss of muscle mass and strength. Early detection and treatment can decrease the risk of developing complications of T2D.

"Testosterone treatment alone is not a replacement for lifestyle intervention, weight management or standard diabetes prevention in older men with central obesity and prediabetes or early T2D," according to Gary Wittert, M.B.B.ch., M.D., of Adelaide University and Royal Adelaide Hospital in Adelaide, Australia, the study's lead author.

Results are based on a sub-study of the randomized, double-blind, placebo-controlled Testosterone for the Prevention of Type 2 Diabetes Mellitus (T4DM) research published in 2021, which involved 1,007 men ages 50–74 who were either at high risk of developing or had newly diagnosed T2D.

While the T4DM study showed that testosterone plus lifestyle intervention reduced the likelihood of diabetes being present after two years, the new research provides deeper insights into a subset of 121 patients who were studied for an additional two years. Wittert led the T4DM study.

The new research extended the T4DM study among a subgroup of 121 participants who elected to continue blinded treatment for two additional years without ongoing enrollment in the lifestyle program. The study aimed to determine the longer-term effects of testosterone treatment on blood sugar, measures of obesity, skeletal muscle mass and strength, sexual function, and safety.

Results show that most of the benefits for blood sugar control occurred in the first two years and diminished by the fourth year. Blood sugar control remained significantly better than in the placebo-treated group. The improvements in body composition (reduction in fat and increase in muscle) and sexual desire that occurred during the first two years were maintained at four years.

Testosterone did not clearly improve overall quality of life compared with placebo at either two or four years. Overall, quality of life was similar between both study groups over the four years. No new safety concerns were identified.

"Our data found that in the specific group of men 50 and older we studied, testosterone alone is not a replacement for changes in diet and exercise, and that it is most beneficial when paired with a lifestyle program. It also may encourage clinicians to look more carefully at men's metabolic health, waist circumference, muscle health, sexual symptoms and testosterone status as connected issues rather than treating them in isolation," Wittert explained.

Key medical concepts

Diabetes Type 2Sexual Dysfunction

Clinical categories

EndocrinologyMen's healthWeight managementHealthy living Provided by The Endocrine Society Who's behind this story?

Sadie Harley

BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Full profile →

Andrew Zinin

Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →

Citation: Testosterone alone is not a replacement for lifestyle changes in older men at risk of type 2 diabetes, new study shows (2026, June 13) retrieved 13 June 2026 from https://medicalxpress.com/news/2026-06-testosterone-lifestyle-older-men-diabetes.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.