• The effect of 6 months of testosterone replacement on diabetes control measured by HbA1c in hypogonadal men with type 2 diabetes treated with insulin. [ Time Frame: 6 months ]
  

• The effect of testosterone on ultrasound measured intima-media thickness of the common carotid artery in the study population [ Time Frame: 6 months ]
  
• The effect of testosterone on male hypogonadism as assessed by the Ageing Males Symptoms (AMS) [ Time Frame: 6 months ]
  
• The effect of testosterone on markers of vascular risk; blood pressure, serum lipid levels, weight, waist circumference, body fat percentage, [ Time Frame: 6 months ]
  
• urinary micro-albumin, tumour necrosis factor alpha, and highly sensitive C reactive protein levels in the study population. [ Time Frame: 6 months ]
  
• The effect of the CAG repeat polymorphism in exon 1 of the androgen receptor gene on the response of the study population to testosterone. [ Time Frame: 6 months ]
  

There is epidemiological data linking low serum testosterone levels in men with the development of diabetes. Clinical trials have indicated a potential benefit of testosterone treatment in improving diabetic control and insulin resistance. Type 2 diabetes is also associated with changes in arterial stiffness and IMT which are known to be linked to the presence of cardiovascular disease. Artificially induced hypogonadism results in increasing arterial stiffness whilst testosterone is known to improve risk factors for vascular disease and act as a vasodilator. The purpose of this pilot study is to test the effect of six months of testosterone replacement, given as testosterone esters 200mg from Sustanon 250 IM injection, on diabetes control in hypogonadal men with type 2 diabetes treated with insulin.

Inclusion Criteria:

• males over 40 years old
• type 2 diabetes treated with insulin
• serum testosterone less than 12nmol/L on 2 consecutive morning samples
• symptoms attributable to hypogonadism

Exclusion Criteria:

• current or previous breast cancer
• current or previous prostate cancer
• raised prostate specific antigen or abdominal digital rectal examination suspicious of prostate cancer unless diagnosis excluded after specialist urology opinion and/or prostate biopsy
• severe symptoms of benign prostatic hypertrophy
• treatment with testosterone in the three months prior to the trial
• investigational drug treatment in the three months prior to the trial