Testosterone therapy improves weight, metabolic profile in older men with hypogonadism

Middle-aged and older men with hypogonadism receiving testosterone therapy lost weight and improved their HbA1c, glucose level, blood pressure and lipid profile, according to research in Clinical Endocrinology.

In an observational registry study comparing men who received continuous testosterone therapy for 11 years with men who interrupted but later resumed therapy, researchers also found that any metabolic benefits were lost once testosterone therapy was stopped, but regained once the therapy was started again.

“This intermission (of testosterone therapy) was not designed, but its occurrence provided an opportunity to monitor the effects of withdrawing [testosterone] treatment on measures of obesity, metabolic factors and well-being,” the researchers wrote. “These effects could be set against the course in men who continued their [testosterone] administration uninterruptedly.”

Aksam Yassin , MD, PhD, of the institute of urology and andrology at Segeberger Kliniken and Dresden International University, Germany, and colleagues analyzed data from 262 middle-aged and older men with hypogonadism receiving testosterone therapy (1,000 mg Nebido, Bayer Pharma). Participants received treatment at baseline, 6 weeks and every 12 weeks thereafter for a maximum of 11 years. Within the cohort, 147 men temporarily stopped testosterone therapy for an average of 16.9 months due to cost reimbursement issues (n= 140) or prostate cancer (n = 7); all of these men resumed testosterone therapy for an average of 14.5 months; 115 men were treated continuously.

The researchers defined three periods of equal duration to compare men who received continuous therapy with those who had interrupted and later restarted therapy: before intermission, during intermission and after intermission; with these same time periods analyzed for participants who had continuous therapy. Researchers measured body weight, BP, glucose levels, lipid profiles and C-reactive protein.

Men in the group receiving continuous testosterone therapy had significant declines in body weight, BMI and waist circumference during the study period. Men in the intermission group experienced the same effect before stopping therapy, when body weight, BMI and waist circumference all increased. Body weight, BMI and waist circumference all declined again for the men restarting testosterone therapy; however, the lower values reached before therapy intermission were not attained, according to researchers.

Men in the continuous testosterone therapy group also saw significant declines in fasting blood glucose, HbA1c, serum cholesterol, LDL cholesterol and triglycerides; men in the intermission group saw the same declines, with levels increasing during therapy intermission and returning to pre-intermission levels once therapy was resumed.

In addition, results from the Aging Males’ Symptom questionnaire, assessing health-related quality of life, showed participating men reported an improvement in overall life quality while receiving testosterone therapy that was lost during therapy intermission, but later regained once restarting therapy.

“Our results strongly indicate that the beneficial changes induced by normalization of serum [testosterone] are not sustained when [testosterone] administration is halted and serum levels return to hypogonadal values,” the researchers wrote. “But these beneficial effects do manifest themselves again upon resumption of [testosterone] administration restoring serum [testosterone] to normal.” – by Regina Schaffer