A known link between low testosterone levels and decreased insulin sensitivity could lead to a treatment for men with type 2.
New study shows that increasing testosterone levels can help male patients with type 2 diabetes increase their response to insulin. In individuals with insulin resistance, their body produces insulin, but does not effectively utilize their insulin.
Insulin resistance leads to a build up of glucose in the blood rather than being absorbed by the cells. Ultimately, insulin resistance can lead to diabetes as well as other health issues such as heart disease.
Testosterone is a hormone that regulates many functions of the body. During puberty, testosterone is responsible for muscle growth, deepening a man’s voice, and increasing the size of the genitalia. In adulthood, testosterone not only maintains a man’s muscles and bones but also his interest in sex. Testosterone levels begin to decrease after 30 years old, which is followed by a decrease in sex drive. Many men mistake the decrease in sex drive as them simply getting older.
Researchers at the University of Buffalo conducted a double blind, placebo-controlled study of testosterone treatment in type two diabetic men. The study evaluated the effect of testosterone replacement therapy on insulin resistant men with type two diabetes and hypogonadism.
The study recruited 94 men with type two diabetes with 50 being eugonadal, normal testosterone levels, while 44 had hypogonadism, low testosterone levels. Baseline lean body mass and body fat were taken prior to study. Subcutaneous fat samples were taken to assess insulin signaling genes. The men with hypogonadism were randomized to receive either intramuscular testosterone (250mg) injections or placebo (1mL saline) every two weeks for 24 weeks.
The results of the showed that men treated with testosterone therapy showed increases in insulin sensitivity, increases in lean mass, and decreases in subcutaneous fat. Insulin sensitivity increased an average of 32% after 24 weeks of testosterone therapy, but did not change for the placebo group (P = 0.03). The test group also lost 3.3 kg in subcutaneous fat while increasing their lean mass by 3.4 kg over the placebo group after treatment. This can be explained by the increase in metabolically active muscle tissue produced by testosterone. The expression of insulin signaling genes (IR-B, IRS-1, AKT-2, and GLUT4) in adipose tissue was lower in men with low testosterone levels before treatment began, and upregulated after the treatment.
Insulin sensitivity increased as well; there was a 32% increase in glucose uptake in tissues in response to insulin, an increase in lean mass and a decrease in subcutaneous fat mass, compared with those men who took the placebo.
These study results show that low testosterone contribute to type 2 diabetes.A previous investigational study in 2010 showed a link between low levels of testosterone and type 2 diabetes. The 2010 study found that 33% of males with type 2 diabetes had low levels of testosterones. With the results from the study, it could be seen that testosterone could be an insulin-sensitizing agent as well as increase skeletal muscle and reduce fatty tissues.
According to study’s corresponding author, Paresh Dandona, MD, this study is the first to show testosterone’s sensitizing effects on insulin; thus, it is a metabolic hormone.
Men with type 2 diabetes are twice as likely to have low testosterone levels compared to men without.
Researchers found that low testosterone levels were associated with significantly decreased insulin sensitivity. This was demonstrated by a 36 percent decrease in the rate at which glucose is taken up by tissues when patients with low testosterone were administered a set concentration of insulin.
Testosterone treatment in men with low testosterone can improve sexual function, increase their energy and activity, elevate their mood, and also increase their strength and bone density. Testosterone treatment can not only help men with their type 2 diabetes, but affect the overall health of the patient.
- Men with type 2 diabetes are twice as likely to have lower testosterone levels as men without.
- 33% of males with type 2 diabetes have low levels of testosterone. Patients should be educated on the signs and symptoms of low testosterone levels and be tested.
- Testosterone treatment can reduce insulin resistance as well as decrease subcutaneous fat tissue as well as increase lean body weight.
- Men with type 2 diabetes who have low testosterone levels can benefit significantly from testosterone treatment.
Dhindsa, Sandeep, et al. “Insulin Resistance and Inflammation in Hypogonadotropic Hypogonadism and Their Reduction After Testosterone Replacement in Men With Type 2 Diabetes.” Diabetes Care (2015): dc151518.