December 3, 2014

ACCORD Final Analysis: Lowering Blood Sugar Improves Heart Disease Outcomes

This paper, Effects of intensive glycaemic control on ischaemic heart disease: analysis of data from the randomised, controlled ACCORD trial, was published by the Lancet last week,

After analyzing the data from the ACCORD study including data from a few years of follow-up, the researchers concluded that lowering A1c resulted in fewer heart attacks, revascularizations (i.e. coronary bypass operations or placements of stents), and unstable angina. The researchers summarized their findings saying,

"Raised glucose concentration is a modifiable risk factor for ischaemic heart disease in middle-aged people with type 2 diabetes and other cardiovascular risk factors." This means you can change that risk by lowering your blood sugar.

You did not see this paper reported in your newspaper, and it is possible your doctor won't see it in his diabetes-related newsletter, either, because it doesn't sound like major news.

But it is very major news, because ACCORD study was the study that, when it was first published in 2008, was interpreted as showing that lowering A1c was dangerous. This was because slightly more people in the "intensive intervention" arm died of heart attacks than did people in the arm of the study who didn't strive to get A1cs of 6.5% or better.

As we blogged years ago, this original conclusion--that lowering A1c could prove fatal--turned out to be a classic case of poor data analysis.  It turned out that the people in the "intervention arm" of the study who had those excess heart attacks were people who though they were were supposed to be lowering their blood sugar had not done so.

Now, as you would expect, better analysis of the ACCORD data shows that lowering blood sugar most definitely does improve cardiovascular health.  This is exactly what we would expect to find, as there is plenty of other evidence from unrelated studies that as A1c rises out of the 5% range the risk for cardiovascular disease starts to rise steeply. You can read summaries of many of these studies HERE.

But the tragedy here is that, back in 2008, endocrinologists who should have known better took the original ACCORD report to mean that lowering your blood sugar below 6.5% is dangerous. And because fo this belief, they actually discouraged their patients from lowering their blood sugars to the levels that it turns out would have protected them from harm.

This is now a huge problem people face when asking doctors to help them achieve tighter control. I have heard from several people with diabetes who have been censured by their doctors for achieving A1cs below 6.5%.  I have also heard from others who were refused treatment that could lower A1cs of 7.0% and post meal numbers shooting into the 200 mg/dl range after meals because their doctors believed that intensive lowering of any kind would be dangerous.

If you fall into this category, or if you are not getting the support you need from your doctor to help you achieve a better blood sugar result, print out the abstract of the Lancet article above and bring it to your next doctor appointment.

Just remember that it isn't enough to lower your blood sugar. You have to do it using dietary approaches and drugs that have a long track record of safety. Cutting carbs works for most people and has been shown to be safe. But right now, only a few diabetes drugs that stand up to my rigorous standards for safety. They are:

gliclazide (not available in the U.S.)

Other drugs like Glyburide, Januvia, Byetta, Actos, and Invokana, along with the many other drugs in the families as these drugs may be very effective for lowering blood sugar, but they lower blood sugar using mechanisms that may over a long period of time harm your body. Januvia and Byetta appear to cause pancreatitis, and may raise the risk of cancer, and alter the immune system. The sulfonylurea drugs like glyburide, glipizide, and glibenclamide stimulate a heart receptor and  increase the risk of heart attack. The drugs like Actos raise the risk of heart failure and osteoporosis. Invokana and related drugs cause urinary tract infections and may cause cancer.

You can learn more about the specific safety issues of the many drugs now prescribed for diabetes at the Drugs page of the main Blood Sugar 101 web site.

So stick to the safe drugs and dietary interventions to lower your blood sugar to as normal a level as you can attain.  Ideally an A1c near 5% is best, but many of us can't achieve them. (I sure can't!) A1cs anywhere in the 5% range are a huge improvement and should give most of us normal health. Keeping your blood sugar under 140 mg/dl as much as possible at all times no matter what your A1c is probably the very best way to protect your arteries and avoid heart disease.


randyfeingersh said...

Please correct me if I'm mistaken, but despite lower non-fatal heart attacks there was higher Mortality in the intensive group. Fewer heart attacks but higher deaths rates in general and more fatal heart attacks.

"Intensive glycemic control was associated with fewer ischemic coronary events despite higher all-cause and cardiovascular-related mortality. - See more at:

Jenny said...

An earlier analysis found that the higher mortality in the intensive group occurred in those in that group who did not actually achieve lower blood sugars.

Just because someone was assigned to the "intensive control" group didn't mean that they actually got better control, only that they were supposed to try for it. Some didn't.

Also remember that Avandia was used to lower blood sugar in that group and another analysis found that its use could also explain that excess mortality. Avandia causes edema and heart failure in people who didn't have it prior to starting.

randyfeingersh said...

Thanks Jenny - The full paper is not freely available but I believe that it also found, as did the earlier paper, increased mortality in the intensely treated group, albeit fewer total non-fatal CV events.

Your point about Avandia (and probably applies to a lot of meds) is crucial. What would be interesting to see is a comparison with folks using intense diet/exercise to lower bg levels compared to follks using drugs. But - that's not likely to happen and that's unfortunate.

Keep up to good work. If find your blog invaluable on staying current.

Jenny said...


The link you cited, which is an earlier publication states: " excess risk for death among intensive-therapy patients occurred only in those whose average on-treatment HbA1c levels were >7.0%,"

The intensive control group was supposed to be getting below 6.5%. So the excess mortality was, as I had said, in those who did not achieve tight control.

This means that those who DID get tight control did not see that excess mortality. This is a round about way of saying that tight control prevents death. They just can't bring themselves to say it.

SM said...

I think our assumption that pure glucose "hits the bloodstream in 15 minutes" is false. I, too, have believed and repeated that many times. However, when I did a self-administered OGTT at home with 75g of glucose, I peaked at 1 hour and 45 minutes. My peak was 320 from a starting point of 85 and I was back to 81 at 4 hours. So, it seems it took a LOT longer than 1 minutes for the glucose to arrive in circulation. I was quite surprised by this.

Jenny said...


When did you first start to see a rise in blood sugar after taking the glucose. It isn't that the glucose peaks at 15 minutes, but that it first starts raising blood sugar at that time.

Once it raises blood sugar, which it will continue to do for a while, if your remaining insulin secretion is slow, it can take a long time for that high blood sugar to disperse.