New treatments for low testosterone levels

Scientists have completed a clinical trial evaluating different therapeutic strategies for low testosterone levels in obese men.

The trial was carried out by a team from the Center for Network Biomedical Research on Physiopathology of Obesity and Nutrition (CIBEROBN) in Spain. The members of the team work from the Málaga Biomedical Research Institute and Nanomedicine Platform (IBIMA BIONAND Platform) and from the Regional University Hospitals of Málaga and Virgen de la Victoria.

Previously, the team showed that obesity causes a drop in testosterone levels, the main male sex hormone, in men, and that there is an inversely proportional relationship between the degree of obesity and testosterone levels, that is, the higher the degree of obesity produces less testosterone.

Among the authors of the study are José Carlos Fernández García, an endocrinologist and clinical researcher at the Regional University Hospital of Málaga, Francisco Tinahones, a CIBEROBN researcher, Scientific Director of the IBIMA BIONAND Platform and head of Endocrinology and Nutrition at the Virgen de la Victoria University Hospital, as well as other members of the ‘Cellular and Molecular Endocrinology’ and ‘Endocrinology and Nutrition, Diabetes and Obesity’ groups, both from IBIMA.

In relation to testosterone levels, José Carlos Fernández indicates that “finding a low testosterone concentration in men is not an unimportant matter, since it has been associated with a worse body composition (more fat mass and less muscle mass), a greater risk of type 2 diabetes, a greater predisposition to erectile dysfunction, a worsening of the quality of life, and a greater predisposition to cardiovascular mortality”.

Jose Carlos Fernandez and Francisco Tinahones. (Photo: CIBER)

Although the reasons why testosterone is lower in obese men are not exactly known, Francisco Tinahones assures that “insulin resistance seems to play a critical role, since it leads to lower testosterone production by the testicles ”.

Usually, the treatment of low testosterone levels is usually the administration of exogenous testosterone. However, the research team has carried out a novel clinical trial (in which more than 100 men with obesity and low testosterone levels have participated), where metformin has been used for the first time – an antidiabetic drug that reduces resistance to insulin-, both as monotherapy and in combination with testosterone, to assess whether it is capable of reducing insulin resistance and increasing testosterone concentrations.

The main results of the study show that both metformin and testosterone, as well as the combination of metformin and testosterone, compared with placebo, reduce insulin resistance, but the combination of metformin and testosterone therapy produces the greatest increase in testosterone concentrations.

The team emphasizes that “although more studies are needed in this line of work, the results obtained provide us with very valuable information on the usefulness of the combination of metformin and testosterone in men with obesity and low testosterone levels.”

The study is titled “Metformin, testosterone, or both in men with obesity and low testosterone: A double-blind, parallel-group, randomized controlled trial.” And it has been published in the academic journal Metabolism. (Source: CIBER)