Study looked at aromatase activity in androgen production in older men. The study found that aromatase inhibition with arimidex increased Testosterone production. PSA was also monitored and PSA increased in the smaller dose group versus the high dose group.
Only abstract available here--high Estradiol:Testosterone, thus high aromatase activity, increased abdominal fat and reduced lean muscle mass. The authors also reported an higher bone mineral density, but that pales in the comparison of the metabolic dysfunction of high fat and low muscle mass causes.