Type 2 diabetes (T2DM) and obesity are closely associated. Hypogonadism is common in both diseases.


Of 823 men with hypogonadism in a registry, 324 (39.4%) have T2DM. Of 63 men with normal weight, 11.1% had T2DM, of 286 men with overweight, 21%, and of 474 with obesity, 54.2%.152 received testosterone undecanoate (TU) 1000 mg/12 weeks (T-group), 172 opted against treatment (CTRL). Changes over time between groups were compared by mixed effects model for repeated measures with random effect for intercept and fixed effects for time, group and their interaction, and adjusted for age, weight, WC, fasting glucose, blood pressure, lipids and quality of life to account for baseline differences between the two groups.


Mean age: 62.7±5.1, follow-up: mean: 7.9, median: 9 years. T-group: weight decreased by 21.8±0.5 kg at 11 years. CTRL: weight increased by 5.8±0.5 kg (p<0.0001 for both). Weight loss was 19.2±0.4% in the T-group and weight gain 6.6±0.4% in CTRL (p<0.0001 for both).T-group: WC decreased by 13.0±0.4 cm. CTRL: WC increased by 6.3±0.4 cm (p<0.0001 for both).T-group: BMI decreased by 7.0±0.2 kg/m². CTRL: BMI increased by 1.8±0.2 kg/m² (p<0.0001 for both).T-group: HbA1c decreased by 2.8±0.3% at 11 years and increased in CTRL by 3.3±0.3% (p<0.0001 for both).Fasting glucose decreased in the T-group by 1.7±0.2 mmol/L and increased in CTRL by 1.6±0.2 mmol/L (p<0.0001 for both). In the T-group, 92 men (60.5%) received insulin at baseline at a mean dose of 36.5±12.2 U/d and 66 in CTRL (38.4%) at a mean dose of 30.8±6.0 U/d. The dose requirement in the T-group declined by 17.7±1.0 U/d and increased in CTRL by 17.7±1.0 U/d (p<0.0001 for both).Since injections were administered in the office and documented, there was a 100% adherence to testosterone therapy.


Long-term testosterone therapy with TU in men with hypogonadism and T2DM sustainably improved anthropometric measures and glycemic control which deteriorated in untreated controls.