Does testosterone treatment improve diabetes control in men with type 2 diabetes and low testosterone?

This study looked at adding testosterone undecanoate (Aveed) to standard therapy for men with type 2 diabetes (T2D) and low testosterone levels. It found that men treated with testosterone had better long-term outcomes and that a third of patients achieved remission from diabetes.

T2D is a metabolic disorder in which the body does not respond well to the hormone insulin, leading to high blood sugar. Patients with T2D may have additional problems with the way their bodies process hormones. Roughly a third of patients with T2D have hypogonadotropic hypogonadism (HH), which occurs when glands in the brain do not release enough gonadotropin hormones. In men, these hormones stimulate the testes to release testosterone. Men with HH have low levels of testosterone and other androgens (male sex hormones). Men with HH and T2D have more inflammation and insulin resistance than other men with T2D.

Artificial testosterone can improve the short-term response to insulin for men with HH and T2D. It is not clear how men with HH and T2D respond to long-term testosterone therapy.

This study included 356 men with T2D, low levels of testosterone (below 12.1 nmol/L), and symptoms of low testosterone. 11 patients had low testosterone due to a problem with the testicles (primary hypogonadism). The rest of the patients had HH. All patients received standard treatment for diabetes, and education on diet and lifestyle to manage diabetes. 178 patients chose testosterone therapy and were given a testosterone undecanoate injection every 12 weeks. 178 patients chose not to have testosterone therapy (controls). Patients taking testosterone were followed for an average of 7.7 years, and controls were followed for an average of 8.7 years. The study lasted 11 years.

Glycated hemoglobin (HbA1c) is a measure of blood glucose control over the previous two to three months. Over the course of the study, the average HbA1c of patients taking testosterone decreased significantly from 9.4% to 5.8%. In comparison, the HbA1c of controls slowly increased over time from 7.8% to 10.5%. When HbA1c is stable below 6.5% without any diabetes medication, the patient is said to be in remission. 34.3% of patients taking testosterone achieved remission of diabetes. None of the control patients achieved remission.

Patients taking testosterone lost an average of 22.1 kg (48.6 lbs) of body weight, while control patients gained weight. Patients taking testosterone had significant improvements in LDL ("bad") cholesterol and triglyceride (blood fats) levels, which are related heart disease. Patients taking testosterone also had improvements in kidney function compared to controls. Patients using testosterone therapy also showed improved quality of life and erectile function, as shown through questionnaires.

The authors concluded that testosterone therapy significantly improved blood sugar control for men with T2D and low testosterone levels. 

Patients who chose testosterone may have differences from those who did not. Additional studies are needed in which the treatment group is randomly selected. Also, this study received partial support from Bayer, the manufacturer of testosterone.

If you have concerns regarding diabetes and low testosterone please discuss this with your doctor.