Testosterone, Metformin, or Both, for Hypogonadism in Obese Males

Inclusion criteria

• Men aged 18 to 50 years.
• BMI > or = 30 kg/m2.
• Total testosterone levels <2.3 ng/ml (<8 nmol/l) or testosterone levels 2.3-3.49 ng/ml (8-12 nmol/l) and free testosterone levels <70 pg/ml.
• LH levels <7.7 mIU / ml.
• No evidence of any other pituitary hormone disruption in morning blood sample (normal concentrations of TSH, FT4, Prolactin, ACTH, cortisol and IGF-1
• Being able to provide informed consent before randomization and agree to comply with all the procedures included in the protocol.

Exclusion criteria

• Intolerance/allergy to metformin or testosterone undecanoate.
• Previous diagnosis of diabetes mellitus (HbA1c> 6.5% or fasting glucose> 126 mg/dl or glucose> 200 mg/dl after an oral glucose tolerance test)
• Treatment with oral hypoglycemic agents, insulin or GLP-1 analogs.
• Poor kidney function: serum creatinine> 2.0 mg / dl.
• Previous history of prostate cancer or breast cancer.
• Active cancer of any kind.
• History of liver tumor or acute or chronic liver disease with impaired liver function: total bilirubin> 2.0 mg / dl or GOT levels three times the upper limit of normal.
• Central hypogonadism of organic cause
• Use in the past 12 months of any drug that affects the pituitary-gonadal axis.
• Use of oral testosterone, oral or transdermal within 2 weeks prior to study entry, or any testosterone ester in the last 6 weeks or testosterone undecanoate injection in the 6 months prior to study entry.
• Uncontrolled hypertension (SBP> 160 mmHg or DBP> 100 mmHg) despite adequate antihypertensive therapy.
• HIV infection or known active infection with HBV or HCV.
• Thrombotic or embolic disease.
• Heart disease, kidney or liver disease.
• Epilepsy or migraine not adequately controlled with treatment.
• Hematocrit> 50% in the screening.
• PSA> 4 ng / ml.
• Severe benign prostatic hypertrophy with an IPSS scale score over 19.
• Evidence of drug or alcohol abuse (> 50 g alcohol / day)
• Hematological diseases that produce increased risk of bleeding after intramuscular injection.
• Serious underlying disease that might affect the patient's ability to participate in the study (eg ongoing infection, gastric ulcers, active autoimmune disease).
• Reduced life expectancy (<12 months) by the presence of comorbidities or advanced terminals.
• Participation in another clinical trial within 30 days before study entry.
• Previous diagnosis of hemochromatosis
• Treatment with phosphodiesterase-5 inhibitors: sildenafil, tadalafil or vardenafil