When you keep your blood sugar level as low as the levels of people who don’t have diabetes, your have little risk of having a heart attack. But when you let your sugar level rise just a little, that risk goes up a lot.
Healthy people who don’t have diabetes have a fasting blood sugar level of less than 6 mmol/l, according to researchers at the University of Copenhagen. That’s the equivalent of an A1C level of 5.4. The Journal of the American College of Cardiology just published their study in the issue for June 19/26, 2012.
The researchers drew on three observational studies that included 80,522 Danes. Observational studies cannot prove a cause, but the researchers went further. They used “a Mendelian randomization approach … to circumvent confounding and reverse causation.”
Those of us who have diabetes have been arguing for years about what a normal A1C level is. My article here three years ago, “The Normal A1C Level,” reviewed the evidence that normal might be as low as 4.2 or as high as 6.0. I think that the jury is still out on the question of whether an A1C level even lower than 5.4 might be safer. But now we have no room for argument that an A1C level above 5.4 is bad for our hearts.
How bad? Even the researchers were surprised. “Over many years, a blood glucose value of only 1 mmol (=18 mg) per liter above normal increases the risk of heart attack by a surprising 69 per cent.”
Let’s put those numbers into the units that we generally use in this country. They’re saying that when our A1C is 6.0 we have a 69 percent greater chance of having a heart attack than when our A1C is 5.4.
This is the most powerful argument that I have ever read that we can’t afford to let our A1C levels rise above 5.4. Heart attacks — which the researchers call by their technical names, ischemic heart disease and myocardial infarction — are serious business.
Heart attacks are the most common cause of death among all adults worldwide and are even more common among those of us who have diabetes. Death certificates of 68 percent of people with diabetes who were 65 or older noted heart disease as a cause of death, according to the U.S. government’s “National Diabetes Fact Sheet, 2011.”
But we are talking about risk, odds, and chance. This is not a game. We can’t afford to gamble with our heart health. And the way to reduce our risk is clearly in keeping our blood sugar as low as possible.
HealthCentral published an earlier version of this article.