Conversely, anabolic/androgenic steroid abuse has been associated with impaired glucose metabolism. In one study, powerlifters that had abused AAS in high doses for up to seven years were shown to have diminished glucose tolerance and increased insulin resistance. In spite of a long history of resistance exercise, these subjects secreted more insulin in response to measured glucose ingestion than even obese sedentary control subjects. Additional studies with methandrostenolone demonstrated significantly increased insulin secretion and potential resistance. A similar outcome is not found in all AAS studies, however. For example, testosterone enanthate in doses as high as 600 mg per week for 20 weeks failed to produce any changes in insulin sensitivity in healthy young men. Nandrolone decanoate (300 mg per week) also did not impair glucose tolerance, and actually improved insulin independent glucose disposal. The data concerning the effects of anabolic/androgenic steroids on insulin sensitivity is difficult to interpret. It does appear that when these drugs are used initially, reductions in body fat are common, particularly visceral adipose tissue. This may actually improve insulin sensitivity and the overall metabolic state, and reduce certain specific risk factors for diabetes and cardiovascular disease. Beyond this, the effects of AAS on glucose metabolism are not fully understood, and difficult to predict. Studies using supratherapeutic doses of testosterone and nandrolone have failed to produce any negative changes, suggesting that moderate AAS abuse is probably not associated with impairments in insulin sensitivity.At the same time, studies do suggest that there could be concerns with heavy steroid abuse. Further research is needed is assess the impact of steroid abuse on metabolic health.
Wlliam Llewellyn (2011) - Anabolics