Obese males between the ages of 14 and 20 reportedly have 50% less testosterone than their normal weight counterparts, which notably decreases their chances of being fertile when they are older.
The study, published online in Clinical Endocrinology, was conducted by the same researchers, from the University at Buffalo’s School of Medicine and Biomedical Sciences, who, in 2004, released a study regarding levels of low testosterone (hypogonadism) found in adult type 2 diabetic males. They verified their findings in 2010 with a trial involving over 2,000 diabetic and non-diabetic obese patients.
Testosterone plays a key part in the development of testis and prostate in men and also boosts increased muscle, bone mass, and body hair growth, which are all secondary sexual traits.
Pubertal effects start to happen later in boys than in girls, much after extended periods of increased testosterone levels in the blood. These increases can result in:
- Sebaceous gland growth – which can cause acne
- Pubic hair growth on thighs and in the direction of umbilicus
- Chest and facial hair growth
- Leg hair growth
- Adam’s apple growth
- Testicles grow spermatogenic tissue – fertility in males
- Remodeling of facial features
- Broadening of shoulders and rib cage
- Libido boost
- Frequent erections
- End of growth span and bone growth
Paresh Dondona, MD, PhD, SUNY Distinguished Professor in the Department of Medicine, and chief of the Division of Endocrinology, Diabetes and Metabolism, commented:
“We were surprised to observe a 50 percent reduction in testosterone in this pediatric study because these obese males were young and were not diabetic. The implications of our findings are, frankly, horrendous because these boys are potentially impotent and infertile. The message is a grim one with massive epidemiological implications.”
Twenty-five obese and twenty-five lean males were involved in the new trial, which was adjusted for sexual maturity levels and age. Total and free testosterone concentrations, as well as an estrogen hormone called estradiol, were calculated in morning fasting blood samples.
Dandona said that more research needs to be done on a larger number of participants, in order to solidify their findings. “These findings demonstrate that the effect of obesity is powerful, even in the young, and that lifestyle and nutritional intake starting in childhood have major repercussions throughout all stages of life, said the author.
Low testosterone levels were also found to be linked to an increased risk of developing belly fat and reduced muscle, which can in turn, result in insulin resistance – a key factor of diabetes.
“The good news is that we know that testosterone levels do return to normal in obese adult males who undergo gastric bypass surgery. It’s possible that levels also will return to normal through weight loss as a result of lifestyle change, although this needs to be confirmed by larger studies.”
The researchers now plan to analyze whether losing weight can help to increase obese teen boys’ testosterone levels. A 2010 study claimed that this is possible, stating that pre-diabetic men can boost their testosterone levels by losing weight.
Written by Christine Kearney