As an endocrinologist, I have educated countless patients with diabetes mellitus about the importance of maintaining good glycemic control. Indeed, currently there is no dispute that inadequate glycemic control contributes to some of the long-term complications of diabetes. However, not too long ago, it was controversial whether lowering blood glucose levels in patients with diabetes would have any beneficial effects.
Medicine is filled with such controversies, which usually result from insufficient or conflicting data, and the field of diabetes is no exception. Currently, the scientific community is divided on whether rosiglitazone, a peroxisome proliferator-activated receptor γ agonist indicated for the treatment of type 2 diabetes, increases the risk of myocardial ischemic events. This finding is based on a meta-analysis of short-term clinical trials and has not been confirmed in longer-term clinical trials. In 2008, a large clinical trial in patients with type 2 diabetes at high cardiovascular risk reported an unexpected finding of increased mortality among patients randomized to undergo near-normal glycemic control compared with those randomized to undergo conventional glycemic control. In contrast, intensive glycemic control did not increase mortality in 2 other recently completed clinical trials.
Joffe HV. Controversies in Treating Diabetes: Clinical and Research Aspects. JAMA. 2009;301(15):1602-1608. doi:10.1001/jama.2009.499