Increased Testosterone Reported in Male Adolescents Following Bariatric Surgery for Severe Obesity

Medical professionals performing laparoscopic surgery. Surgeons are with patient in operating room. They are holding surgical equipment.
A team of researchers investigated the effect of bariatric surgery on testosterone levels in adolescents with severe obesity.

Bariatric surgery was found to be associated with a robust increase in testosterone concentrations in male adolescents with severe obesity, according to the results of a study published in the European Journal of Endocrinology.

Researchers reported results based on Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS; Identifier: NCT00474318), a prospective, multicenter, observational study conducted in adolescents (≤19 years of age) who had undergone bariatric surgery of any type from March 2007 through February 2012. The study enrolled 242 participants (59 male) who were followed up for 5 years following bariatric surgery.

The current results are from an ancillary study in which serum from male participants was used to measure testosterone, estradiol, sex hormone-binding globulin, and gonadotropins. The primary endpoint was the change from baseline in calculated free testosterone concentrations 5 years following bariatric surgery.

Serum samples were collected before surgery and at 6, 12, 24, 36, 48, and 60 months. Baseline serum samples were available for 34 male participants and were included in the current analysis. The cohort had a mean age of 17.4±1.5 years and a mean body mass index (BMI) of 53.1±10.6 kg/m2; 82% were White.

Maximum BMI loss in participants was achieved by 12 months, with a slight regain observed from 24 to 36 months (P =.032). By 5 years, the mean percentage change in BMI from baseline was -28.7% (95% CI, -33.0 to -24.4).

Participants had a baseline total testosterone concentration of 6.7 nmol/L (95% CI, 4.7-8.8), which increased significantly to 17.6 (95% CI, 15.3-19.9) at 2 years (P <.001), with similar values being reported at 2 to 5 years. Baseline free testosterone concentrations increased from 0.17 nmol/L (95% CI, 0.13-0.20) to 0.34 nmol/L (95% CI, 0.30-0.38) by 2 years (P <.001); these concentrations decreased at 3 years (P =.014) and were similar afterward.

Before surgery, 79.4% (95% CI, 67.5-93.5) of the study participants had subnormal total testosterone concentrations (<9.2 nmol/L), and at 5 years following surgery the prevalence was significantly decreased to 21.6% (95% CI, 9.6-48.5; P <.001).

Also among the cohort, 72.7% (95% CI, 58.7-59.9) of the study participants had subnormal free testosterone (<0.23 nmol/L) concentrations at baseline, with the prevalence significantly reduced at 5 years to 33.1% (95% CI, 17.8-61.7).

By 5 years, 71.4% (95% CI, 51.1 to 100.0) of the study participants with low baseline total testosterone had a normal concentration. More than half (54.6% [95% CI, 31.5-94.5]) of the study participants with subnormal free testosterone concentrations at baseline had levels restored to normal by 5 years.

Among several study limitations, data were lacking on participants’ pubertal status, and the volume of serum was insufficient to perform equilibrium dialysis on the samples. Also, the analysis did not include a comparator arm of male participants who did not undergo bariatric surgery, and data were not available regarding symptoms or signs of hypogonadism.

“There was a progressive increase for 2 years in total and free testosterone concentrations following the surgery, after which the concentrations tended to decline,” stated the researchers. “This decrease may have been the result of weight regain that followed.”

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Dhindsa S, Ghanim H, Jenkins T, et al. High prevalence of subnormal testosterone in obese adolescent males: reversal with bariatric surgery. Eur J Endocrinol. 2022;186(3):319-327. doi:10.1530/EJE-21-0545