For men with low testosterone, increasing testosterone can improve quality of life, as well as promote weight loss and blood sugar control.
Low testosterone is associated with low sex drive, soft and small testes, decreased sperm counts, decreased bone density and muscle mass, and increased body fat. Large studies have shown that testosterone levels decline with age. In addition, conditions such as diabetes, heart disease, metabolic syndrome, obesity, HIV infection, varicocele, alcohol abuse, narcotic use, and steroid use have been associated with low testosterone.
Testosterone replacement results in increased lean body mass, decreased fat mass, decreased waist circumference, improved blood glucose (measured by glycosylated hemoglobin HgbA1c) and blood pressure, and decreased “bad” cholesterol. In addition to these benefits, however, there are some possible risks to testosterone replacement (especially for men over 65 years and those with cardiac history) which must be carefully considered with your physician before starting any treatment.
Multiple randomized controlled trials describe significant benefits to lean body mass, waist size, with multiple preparations (gel and injectable) and duration from 3-36 months in overweight men.
A recent study describes such benefits of testosterone replacement through 5 years of follow-up with significant and maintainable weight loss for hypogonadal men. 261 men with average age of ~60 years shed an average of over 10% of their body weight (mean weight loss of 11.1 kg, 1/3 of the men lost 15 kg or more) and body-mass index (a measure of obesity) declined following five years of treatment. Treatment in this case was injectable testosterone undecanoate 1000 mg initially followed by another injection at 6 weeks, and then every 12 weeks for up to 5 years. Testosterone was identified to more than double from baseline in the first year of treatment, and then plateaued following this. 1/3 of the men in the study had a BMI of 30 kg/m2 or greater (which declined from average 31.7 kg/m2 to 29.4 kg/m2 at 5 years) and nearly 70% had a waist size of 102cm or greater. Waist size declined in 97.5% of the men (average size reduction of 9.4 cm). Overall, the most obese men had the greatest reductions in weight, waist size, and BMI. The importance of men with low testosterone being identified and treated is highlighted in the benefits to weight, waist circumference, cholesterol, and sugar control (and others mentioned here). Of course, patients must have a full discussion of risks and benefits of testosterone replacement with their physician.
–Matthew Wosnitzer, M.D.
November 3, 2013