A small study found that hypogonadal men with type 2 diabetes saw improved blood sugar levels and arterial function after starting testosterone replacement therapy. These results are not surprising, but it's good to see a blinded study confirming them. The abstract says:
Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n = 28) was treated with testosterone undecanoate (1000 mg i.m. every 10 weeks) while group P (n = 27) received placebo. TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.