Dr. Ehud Ur (University of British Columbia, Vancouver, BC) said the debate demonstrated that intensive blood glucose lowering in Type 2 diabetes to protect against CV outcomes is still a "gray area.However, in many ways the question is moot," he noted. "We still have to lower glucose in order to prevent microvascular disease. Whether we do it because we are lowering microvascular disease or macrovascular disease doesn't really make any difference in a practical sense."

According to Ur, "The take-home message is we need to lower glucose anyway, we need to do studies in order to identify the drugs that are best placed to do that, and we need to further understand the early processes that take place that are clearly key in determining long-term outcomes."

Diabetes flags a patient who has a high risk of CVD, requiring optimal CV prevention strategies, Ur noted. "We're still not achieving aggressive lipid lowering in these patients," he said. "Many diabetic patients are not even on statins, and some aren't even having their lipids checked. Those are really things that need to be done early and need to be done aggressively."

"In terms of glucose control, we still have an HbA_1c target of 7%. Clearly, early on in the disease or in patients who are not yet on insulin, some of the straightforward oral agents, particularly metformin, are indicated," he said.

When determining treatment strategies for patients with Type 1 diabetes, the case "for" intensive glucose control is "open and shut," saidDr. Hertzel C. Gerstein (McMaster University, Hamilton, ON). The Diabetes Control and Complications Trial (DCCT) showed that "if you are young and have relatively recently been diagnosed with Type 1 diabetes, after at least six years of intensified insulin therapy, you reduce your 20-year risk of CV events by 42%," he said.

For Type 2 diabetic patients, however, the evidence for tight glucose control, based on four large randomized controlled trials -- UKPDS, ACCORD, VADT, and ADVANCE -- is not so straightforward, he said.

Gerstein stated that, "A summary of those four large outcome trials of different glucose-lowering intensities in people with Type 2 diabetes showed that, on average, there is a modest 9% reduction in CV events and no effect on mortality, but there are differences in some of the outcomes.

The trials showed that "if you have newly diagnosed Type 2 diabetes, at least 10 years of intensive glycemic therapy will reduce your 20-year risk of mortality and MI," he summarized.

Evidence does show that tight glucose control can reduce retinopathy, neuropathy, and nephropathy, he said. According to Gerstein, "the most important message is that although glucose lowering does seem to have a benefit, a lot more research is required to understand whether certain drugs vs other drugs are providing the effect."

Glucose-lowering for the prevention of cardiovascular disease: positive, negative, or neutral? International Diabetes Federation 20th World Diabetes Congress; October 21, 2009; Montreal, QC.