Background: According to 2016 AACE/ACE obesity guidelines, hypogonadism should be assessed and treated in indicated in men with type 2 diabetes mellitus (T2DM).

Methods: In a registry of hypogonadal men (testosterone ≤12.1 nmol/L) conducted since 2004 in a urological setting, 133/400 patients (33.3%) had T2DM diagnosed and treated in a diabetes center. All men received testosterone undecanoate (TU) injections 1000 mg/12 weeks (T-group) following an initial 6-week interval. Anthropometric and metabolic parameters were measured at least twice a year and fasting insulin obtained from the diabetes center to calculate HOMA-IR.

Results: Mean follow-up was 6.9, maximum 11 years. 16 patients (12%) were in remission at the last measurement. Their average baseline age was 60.1 years. HbA1c dropped from 8.3% at baseline to 5.7% at the last measurement, fasting glucose from 7.8 mmol/L to 5.4 mmol/L. Fasting insulin declined from 24.7 to 7.6 µU/mL. HOMA-IR dropped from 8.7 to 1.8. Triglycerides decreased from 3.2 to 2.2 mmol/L. Anthropometric parameters: Body weight declined progressively from 107 to 89 kg, waist circumference from 1to 97 cm. All patients had been on oral antidiabetic medication (metformin) at baseline. Five patients were on insulin at an average dose of 21.6 units per day. The average observation time was 106.3 months (8.9 years). The average time to discontinuation of diabetes medication was 74.8 months (6.2 years). One patient was diagnosed with low-grade prostate cancer and developed new onset T2DM while off TU. He went into remission 48 months after resuming TU therapy. Medication adherence to TU was 100 per cent as all injections were administered in the urology office and documented.

Discussion: The registry was not designed to study the effects of testosterone on T2DM. Remission of T2DM has not been described in the literature and was unexpected.

Conclusions: Long-term testosterone treatment in hypogonadal men may result in remission of T2DM.


A. Haider: Research Support; Self; Bayer AG. K.S. Haider: Other Relationship; Self; Bayer AG. F. Saad: Employee; Self; Bayer AG. Stock/Shareholder; Self; Bayer AG, Novo Nordisk A/S.

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