The Nutrition Debate #226: Improved Glycemic Control and CV Risk

Last week, Marlene Busko (Medscape Medical News) reported on a poster presentation at the American Diabetes Association (ADA) 2014 Scientific Sessions in San Francisco. The “new, real-world study, based on real clinical practice,” demonstrated “a very strong effect” of glycemic control on cardiovascular outcomes, Busco reported. The lead author of the study was Dr. Nick Freemantle, 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 takeaway I got was that “it doesn’t appear to matter how you get to (glycemic) control; it’s getting to control that matters.” The message, as Dr. Freemantle said, is 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.” [Weren’t eating a low-carb diet, were they?] “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, their median HbA1c was 9.3% (range 8.1 – 10.7%). Like me, nearly 12 years ago, these patients were obviously relying solely on their doctors to manage their type 2 diabetes. The result: their disease progressed to the point where their doctors started them on insulin.

So, what happened? “Patients whose HbA1c levels remained high had worse outcomes.” How much 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 meds not commonly used in the U.S.

The starting dose of insulin was a low 0.20 U/kg body weight, which was then titrated upward as needed, Medscape reported. “The patients made substantial gains in glucose control,” Dr. Freemantle 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,” Dr. Freemantle said.

The guided-poster-tour moderator, an MD, 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 sounds like a safe conclusion to me! 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!

This study was funded by Sanofi, a major manufacturer of insulin (Lantus and Apidra), but that in no way, in my opinion, changes the outcomes. It just happens, not surprisingly, that the outcomes benefit them by promoting the use of “low-dose insulin in combination with other therapies.” So be it. But remember the takeaway:  “it doesn’t appear to matter how you get to (glycemic) control; it’s getting to control that matters.” To reiterate - “achieve improved HbA1c…by whatever means,” as Dr. Freemantle said.

Obviously, neither cohort in this study considered dietary choices as part of their diabetes care. They relied on their doctors to take care of them. They “had had diabetes for about 9 years but had hyperglycemia. And, despite taking up to 3 oral antidiabetic agents, their median HbA1c was 9.3% (range 8.1 – 10.7% or an average glucose level of 186 to 260). My HbA1c, after 16 years of letting my doctor prescribe progressively more anti-diabetic meds (3 total), and doing nothing on my own behalf, had been as high as 8.9%. Up until this point, I can see myself in their shoes. I was there.

But here’s the critical difference: their disease progressed to the point where their doctors started them on insulin; my doctor started me on a Low Carb diet. I not only lost a huge amount of weight. I was able to discontinue my meds!!!