Testosterone Treatment May Have Non-Sexual Benefits
WASHINGTON, DC—Restoring plasma testosterone levels to normal in elderly hypogonadal men may significantly improve components of the metabolic syndrome and improve nonalcoholic fatty liver disease, data suggest.
“Physicians are often reluctant to prescribe testosterone for conditions not related to sexual function,” said co-investigator Farid Saad, PhD, head of scientific affairs for Men's Healthcare at Bayer Schering Pharma in Berlin and an honorary professor in clinical research and endocrinology at Gulf Medical College, Ajman, United Arab Emirates.
“However, our study shows that testosterone has a much wider therapeutic role than just for improving sexual desire and erectile function.”
The metabolic syndrome is associated with lower than normal testosterone levels, Dr. Saad observed. Nonalcoholic fatty liver disease is an important factor in the pathogenesis of the metabolic syndrome and is linearly correlated with all of its components. Researchers believe cytokines secreted by visceral adipocytes may depress peripheral insulin-mediated glucose uptake and increase hepatic fat accumulation.
Dr. Saad and his colleagues studied the effects of testosterone administration on variables of the metabolic syndrome and on liver function and C-reactive protein (CRP), and reported findings here at the Endocrine Society's 91st Annual Meeting.
The study included 122 testosterone-deficient men aged 36-69 (mean age 59.5 years). All subjects were treated for 24-30 months with parenteral testosterone undecanoate to normalize plasma testosterone levels. Testosterone undecanoate, a slow-release formulation of the hormone, is not yet available in the United States.
Restoring testosterone to normal levels led to major and progressive improvements in many features of the metabolic syndrome. Weight, waist line, and BMI declined over the study period. Other metabolic risk factors improved significantly during the first year of testosterone treatment.
Of the 47 men who met the criteria for metabolic syndrome at the beginning of the study, 36 men (77%) no longer had the diagnosis after 24 months of treatment.
Liver function significantly improved during the first 12 to 18 months of therapy and then stabilized for the remainder of the study period. Treatment also greatly decreased blood levels of CRP, a measure of inflammation linked to increased risk of cardiovascular disease.
“We conclude that testosterone therapy in men with testosterone deficiency can largely improve or even remedy the metabolic syndrome, which will most likely decrease their risk of diabetes and cardiovascular disease,” Dr. Saad said.
Nonalcoholic fatty liver disease, also called fatty liver, commonly occurs with metabolic syndrome and may aggravate the problems associated with it. To receive a diagnosis of the metabolic syndrome, patients must have three of the following risk factors: abdominal obesity, low HDL cholesterol, high triglycerides, high BP, and high blood sugar.
“The findings, in a way, are surprising because when you look at the labels of testosterone products there is always a warning that liver function needs to be monitored because liver function could become worse,” said co-investigator Ahmad Haider, MD, a specialist in urology and andrology in private practice in Bremerhaven, Germany.
“This warning, however, is for the older testosterone products and not the modern products such as the testosterone gel or testosterone undecanoate.”