Effects of intermission and resumption of long-term testosterone replacement therapy on body weight and metabolic parameters in hypogonadal in middle-aged and elderly men

Objective In addition to primary and secondary ('classical') hypogonadism, hypogonadism occurring in middle-aged and elderly men has been recognized. There is evidence that restoring T levels to normal improves body weight, serum lipids and glucose levels. Design Observational registry study. Patients Two hundred and sixty-two hypogonadal, middle-aged and elderly, men received testosterone replacement treatment (TRT). After having been on TRT for a mean duration of 65.5 months, TRT was temporarily intermitted in 147 patients for a mean of 16.9 months (Group I) due to cost reimbursement issues and in seven men due to prostate cancer. All these men resumed TRT for a mean period of 14.5 months. Of the cohort, 115 men were treated continuously (designated as Group C). To compare on-treatment to off-treatment periods, three periods of equal duration were defined: pre-intermission (on TRT), during intermission (off TRT) and post-intermission (on TRT after resumption of TRT). For proper comparison, the same periods were analysed for those patients who continued TRT throughout (Group C). Measurements Variables of body weight, glucose metabolism, lipids, blood pressure and C-reactive protein (CRP). Results In Group C there was a continuous improvement of body weight, serum lipids, glucose, HbA(1c), blood pressure and CRP. In Group I there was a similar initial improvement which was reversed upon intermission of T administration but which appeared again when T treatment was reinstated. Conclusions Our observation indicates that T administration improves body weight and metabolic factors in men with hypogonadism but withdrawal of T reverses these beneficial effects to appear again when TRT is resumed.