Introduction: Abdominal adipose tissue suppresses testosterone production by various mechanisms affecting the hypothalamic–pituitary–gonadal axis. Hypogonadism leads to further accumulation of fat mass thus creating a vicious circle. This study analysed the effects of restoring testosterone in obese hypogonadal men.
Methods: Cumulative, prospective, registry study of 181 men (mean age: 59.11±6.06 years) with testosterone levels below 12.1 nmol/l and a BMI of ≥30 kg/m2. All men received parenteral testosterone undecanoate 1000 mg/12 weeks following an initial 6-week interval. 89 men were treated 5 years, 114 4 years, 133 3 years, 159 2 years, 181 1 year. The changing numbers do not reflect drop-out rates but are a result of the design as new patients are added once they have received at least 1 year of treatment.
Results: At the end of the observation period, mean weight (kg) decreased from 114.71±11.59 (minimum 87.0, maximum 139.00) to 93.24±8.49 (min 80.0; max 115.0). This decrease was statistically significant vs baseline .
Waist circumference (cm) as a measure of abdominal fat decreased from 111.2±7.54 (min 89.00; max 129.00) to 100.47±7.11 (min 84.00; max 117.00), BMI from 36.72±3.72 (min 30.10; max 46.51) to 30.22±2.6 (min 25.66; max 36.71).
Fasting glucose decreased from 5.84±0.84 to 5.41±0.12 mmol/l, total cholesterol from 7.63±0.95 to 4.9±0.28, LDL from 4.47±1.03 to 2.94±0.93, triglycerides from 3.31±0.56 to 2.17±0.13 mmol/l. Systolic blood pressure decreased from 159.17±15.9 to 139.08±10.99 mmHg, diastolic blood pressure from 96.5±11.01 to 80.39±7.51 mmHg (P<00001 p="">
Conclusion: Normalising testosterone produced loss of weight/waist circumference and improved metabolic profile. These improvements were progressive over 5 years.