VANCOUVER—Obese hypogonadal men who received long-term testosterone injections experience a gradual decline in weight and waist circumference, according to study findings presented at the 33rd Congress of the Societé Internationale d’Urologie.
This effect, researchers concluded, may be beneficial for cardio-metabolic and urological outcomes.
Abdulmaged Traish, MBA, PhD, professor of biochemistry and urology at Boston University School of Medicine, led the prospective, Bayer-funded registry study of 181 men who, at baseline, had a testosterone level below 12.1 nmol/L and a body mass index (BMI) of at least 30 kg/m2. Subjects’ mean age was 59.1 years (range 33-69 years). Each received one 1,000-mg testosterone undecanoate parenteral injection and, starting six weeks later, received this same dose every 12 weeks for up to five years. All of the men had dyslipidemia, 97% had hypertension, 39% had type 2 diabetes, 22% had coronary artery disease, and 19% had experienced a previous myocardial infarction. One patient was diagnosed with prostate cancer after 10 months of treatment.
The researchers tracked subjects’ testosterone trough levels and found that, starting at 12 months of treatment and going out to 60 months, the levels were significantly higher than baseline levels. At the same time, subjects’ body weights and waist circumferences fell significantly. They lost an average of 18.83 kg from a baseline average weight of 114 kg, and 9.87 cm from an average baseline waist circumference of 111 cm. The men’s mean BMI also declined significantly, from 36.72 kg/m2 at baseline to 30.22 kg/m2 at the 60-month mark.
These changes took place gradually, with the men experiencing significant year-to-year weight, waist circumference, and BMI losses each year. Ninety-nine percent of the men lost at least 5 kg over the five-year period, while 70% lost at least 15 kg and 40% lost at least 20 kg.
About 3%-5% of the men gained weight, averaging 1-2 kg. “Most of these men have some inflammatory diseases, and the weight gain is explained by the fact that their inflammation got better and they were able to gain some weight,” Dr. Traish said.
Other changes the men experienced over the duration of the study included a:
- gradual and steady drop in average residual bladder volume, starting at 52 mL and falling to 20.5 mL by 57 months
- gradual increase in average prostate volume, starting at 31 mL, rising to 34 mL at three years and falling again to 32 mL at 60 months
- slight but statistically significant increase in average PSA levels, starting at 1.8 ng/mL and rising to 1.95 ng/mL at the five-year mark
- steady drop in average International Prostate Symptom Score, falling from 7.8 at baseline to 3.5 at three years and 2.9 at five years
- sharp fall in average C-reactive protein levels, from 4.0 mg/dL at baseline to 0.8 mg/dL at five years
- gradual increase in average score on the International Index of Erectile Function-Erectile Function subscale, starting at 21.1 at baseline and reaching 25.25 at the 60-month mark
Long-term testosterone treatment also produced positive effects on lipid profiles (reduction in total and LDL cholesterol, increased HDL cholesterol, and reduction in triglycerides), and decreases in fasting blood glucose, hemoglobin A1c, and inflammation. The study has been accepted for publication in the International Journal of Clinical Practice.