Retrospective #226: Improved Glycemic Control and CV Risk

A Medscape Medical News story on a Poster Presentation at the American Diabetes Association (ADA) 2014 Scientific Sessions in San Francisco made an important, but unstated, point. The “new, real-world study,” the report said, “based on real clinical practice,” demonstrated “a very strong effect” of glycemic control on cardiovascular outcomes.” The lead author of the study was a professor of epidemiology and biostatistics at University College London.

The lede for the Medscape piece was, “Among patients with Type 2 diabetes who start taking insulin, those who attain good glycemic control are less likely to have a major adverse cardiac event (MACE) in the medium term than those who fail to achieve this.” But the unstated point was that “it doesn’t appear to matter how you get to (glycemic) control; it’s getting to control that matters.” The message was to “achieve improved HbA1c…by whatever means.”

“The study covered nearly 3,000 patients who had had diabetes for about 9 years but had hyperglycemia despite generally receiving oral antidiabetic agents.” That’s like me, before starting a low-carb diet. “The patients had a mean age of 61, about half were women, and at baseline they had a median body mass index of 28.6.” Despite taking up to 3 oral antidiabetic agents [again, like me], their median HbA1c was 9.3% (range 8.1 – 10.7%). These patients were relying solely on their doctors to manage their Type 2 diabetes. The result: their disease had progressed to the point where their doctors HAD to start them on insulin.

So, what happened? “Patients whose HbA1c levels remained high had worse outcomes.” How much worse? 25% worse. “Specifically, a 1% higher HbA1c increased the risk of a major adverse cardiac event (MACE) during a 4-year follow-up by 25% compared with an otherwise similar patient with a 1% lower A1c.” The “1% increase in HbA1c above the mean was associated with a significant 36% increased risk of a first stroke, and a significant 31% increased risk of cardiovascular death. During the study follow-up, there were 44 nonfatal MIs (myocardial infarctions, or heart attacks), 57 nonfatal strokes, and 60 deaths from cardiovascular causes. There were 148 deaths from all causes.”

Seven percent were not taking any oral antidiabetic agents when they began insulin therapy. About a quarter were taking 1, half of the patients were taking 2, and a fifth were taking 3 orals. Two thirds of the patients were taking Metformin, three-quarters a sulfonylurea (!), twenty percent were on a TZD, and the rest on other diabetes meds.

“The patients made substantial gains in glucose control,” the lead author said. “The median HbA1c dropped to 7.4% (range 6.7% – 8.4%) at 1 year and remained around that level at years 2, 3 and 4.” “The results confirm that people with better blood glucose control have better cardiovascular outcomes,” the author said.

The guided-poster-tour moderator told Medscape Medical News, “This study suggests (that) getting glycated hemoglobin down with low-dose insulin in combination with other therapies is safe and might be beneficial by reducing CV events.” That’s a safe conclusion! He added, “Although it was not a prospective study with a comparator arm, nevertheless it reinforces that ‘good glycemic control is important to prevent cardiovascular events.’” Duh!

Not surprisingly, this study was funded by Sanofi, a manufacturer of insulin (Lantus and Apidra), So, the outcomes benefited them by promoting the use of “low-dose insulin in combination with other therapies.” But remember the takeaway: “It doesn’t appear to matter how you get to (glycemic) control; it’s getting to control that matters.”

Unfortunately, this study did not consider dietary choices as part of their diabetes care. But neither did it exclude diet. It doesn’t matter how you get control; it’s getting control that matters. In this study, the patients relied on their doctors to take care of them, and they “had had diabetes for about 9 years but [still] had hyperglycemia [high A1c’s].

My Fasting Blood Sugars, after 16 years of letting my doctor prescribe progressively more anti-diabetic meds (3 total), and doing nothing on my own behalf, was still in the 150s. Like these patients, I was on the verge of injecting insulin. But here’s the critical difference: instead of insulin, my doctor started me on a Very Low Carb diet. I not only lost a great deal of weight, I had to discontinue most of my antidiabetic meds to avoid hypoglycemia (low blood sugar)!