ST. LOUIS – Obese adolescent boys who lose weight following bariatric surgery improve
their testosterone levels, according to Saint Louis University School of Medicine
and University of Buffalo researchers.
The study, “High Prevalence of Subnormal Testosterone in Obese Adolescent Males: Reversal
with Bariatric Surgery,” published in the European Journal of Endocrinology.
Sandeep Dhindsa, M.D., a SLUCare endocrinologist and the director of SLU’s Division of Endocrinology, Diabetes
and Metabolism, is first author on the paper.
“Obese boys do not achieve sufficient testosterone levels at puberty and weight loss
can theoretically improve testosterone,” Dhindsa said. “We checked the testosterone
levels in obese boys who underwent bariatric surgery. Those who lost weight had increased
testosterone levels. Those who regained weight had a lowering of testosterone again.”
In the study, researchers evaluated the changes in sex hormones following bariatric
surgery in 34 male patients between the ages of 14-19. These participants were part
of a long-term multi-center study, the Teen-Longitudinal Assessment of Bariatric Surgery
Teen-LABS is the first large study to systematically document the outcome of metabolic
bariatric surgery for treatment of adolescents with severe obesity in the United States.
The participants were followed for five years following surgery. Total testosterone,
estradiol, luteinizing hormone, follicle stimulating hormone, sex hormone binding
globulin, insulin and glucose were measured before surgery, six months’ post-operative
and annually thereafter. The study showed that bariatric surgery, in addition to treating
obesity and reversing Type 2 diabetes, reversed low testosterone levels.
“Males usually achieve their peak testosterone concentrations at puberty, followed
by a gradual decline for the rest of their life. Adolescent males with obesity start
off with a lower testosterone. We do not know the long-term effects on fertility and
sexual function. Testosterone is also important for muscle and bone growth. Our study
provides strong evidence that weight loss can restore normal testosterone concentrations
in these boys,” Dhindsa said.
Prior to surgery, 73% of participants had subnormal free testosterone levels. Two
years later, only 20% had subnormal free testosterone concentrations. Five years later,
that percentage rose to 33% due to regained weight among some participants.
Common causes of low testosterone in adults are aging, obesity and diabetes. Male
adults with obesity have lower testosterone levels than lean adults.
This work was supported by the National Institutes of Health (NIH), grant numbers
UM1D072493 (University of Colorado) and UM1DK095710 (University of Cincinnati). Funding
for the ancillary study was provided by the Divisions of Endocrinology of University
of Buffalo and Saint Louis University.
The study’s senior author is Paresh Dandona, M.D., SUNY Distinguished Professor at
the Jacobs School of Medicine and Biomedical Sciences at the University of Buffalo.
Additional authors include Husam Ghanim, Ph.D., Division of Endocrinology, Diabetes
and Metabolism, Jacobs School of Medicine and Biosciences, University of Buffalo;
Todd Jenkins, Ph.D., Division of Pediatric General and Thoracic Surgery, Cincinnati
Children’s Hospital Medical Center; Thomas H. Inge, M.D., Ph.D., University of Colorado
Denver and Children’s Hospital Colorado; Carroll M. Harmon, M.D., Ph.D., Division
of Pediatric Surgery, John R. Oishei Children’s Hospital and Jacobs School of Medicine
and Biosciences, University of Buffalo; Amit Ghoshal, Ph.D., Quest Diagnostics, Nichols
Institute; Zengru Wu, Ph.D., Endocrine Division, Quest Diagnostics, Nichols Institute;
Michael J. McPhaul, M.D., Endocrine Division, Quest Diagnostics, Nichols Institute;
and Farid Saad, DVM, Ph.D., Gulf Medical University, Research Department.
Dhindsa is a former fellow in the Division of Endocrinology, Diabetes and Metabolism
in the Jacobs School at University of Buffalo.
Saint Louis University School of Medicine
Established in 1836, Saint Louis University School of Medicine has the distinction
of awarding the first medical degree west of the Mississippi River. The school educates
physicians and biomedical scientists, conducts medical research, and provides health
care on a local, national and international level. Research at the school seeks new
cures and treatments in five key areas: cancer, liver disease, heart/lung disease,
aging and brain disease, and infectious diseases.