May 28, 2011

Insight into Why A1c Correlates So Strongly with Heart Attack

The evidence has been accumulating throughout the past decade that the A1c test is a much better predictor of heart attack than any test of cholesterol levels. You can find summaries of the major studies that have established this finding HERE.

Now scientists have discovered a mechanism that may explain why this is the case. The study is Glycation of LDL by Methylglyoxal Increases Arterial Atherogenicity: A Possible Contributor to Increased Risk of Cardiovascular Disease in Diabetes. Naila Rabbani et al. Diabetes. Published online before print May 26, 2011, doi: 10.2337/db11-0085

You can read a good explanation of what this study means in this report from Science Daily:

Science Daily: Super-Sticky 'Ultra-Bad' Cholesterol Revealed in People at High Risk of Heart Disease

In brief the finding is this: LDL becomes dangerous mostly when it becomes glycated--i.e. when sugar molecules become bonded to it. When that happens it is more likely to stick to the artery walls. The oft-demonstrated close correlation between A1c and heart attack suggests that this dangerous glycation of LDL occurs at the same rate as the glycosylation of red blood cells--which what the A1c test measures.

This goes a long way to explaining why there is such a poor correlation between measured LDL levels and the occurrence of heart attack. Though the makers of expensive statin drugs have brainwashed doctors into believing that high cholesterol translates into high risk of heart attack quality research has never borne this out--just as it hasn't borne out the idea that lowering cholesterol with statin drugs will prevent heart attacks in the general population.

If this newest research finding holds up, it may turn out that testing for glycosylated LDL will predict with good accuracy whose LDL levels put them at risk for clogged arteries.

If that turns out to be the case, it may finally get through to doctors that the best approach for preventing heart attacks will not be statins--which don't alter the glycation of LDL. Instead, the key to preventing heart attack will be to keep blood sugar from rising outside of the truly normal level after meals.

What is that truly normal level? Research has made it crystal clear. It is under 140 mg/dl (7.7) at one hour after eating. Additional heart=attack-specific research suggests that the likelihood of having a heart attack rises significantly when post meal blood sugars go over 155 mg/dl (8.6 mmol/L) at one hour after eating.

Not so surprisingly, if you keep blood sugars in the truly normal range you will also end up with an A1c that is in the range 5% and under range that other research has found correlates with a very low risk of heart disease.

Insight into Why Trials of Lowering A1c in the Elderly Don't Lower Heart Attacks

This new finding about glycated LDL also explains why studies of elderly patients who have lowered their A1c only after decades of exposure to very high blood sugars do not show that lowering A1c reduces heart attacks. The longer the time period during which your arteries are exposed to glycated LDL, the more of it is going to accumulate in your arteries. When thick plaques have established themselves in your arteries it may be too late. The ideal time to get aggressive about blood sugar control is as soon as you see a slight elevation in your fasting blood sugar or see one hour values over 140 mg/dl when testing your blood sugar after meals.

In fact, it's my guess that the single best thing we could do to screen for potential heart disease would be to ask people to buy a cheap blood sugar meter and test their blood sugar one hour after eating ten different meals. If the test results show repeated readings over 140 mg/dl aggressive steps should be taken to lower blood sugar.

What are those steps? You'll find them here:

How to Lower Your Bood Sugar.

This technique looks so simple, it's easy to dismiss it. But give it a try. If you do, you may be shocked at how well it works. I hear from dozens of people each week reporting that it does just that--including nurses and even, occasionally, registered dietitians. They start with A1cs that range from only slightly elevated in the low 6% range to those that are as high as 13%. But every one of my correspondents reports that they are able to achieve normal blood sugars in the 5% range--and so can you.

Start with the dietary strategy described in the link above and if dietary change isn't enough ask your doctor about adding metformin, the only oral diabetes drug that has been shown over decades of research to lower the incidence of heart attack.

If your doctor brushes off your request for help in lowering your blood sugar and suggests that all you need is to take a statin drug, it's time to find another doctor.

NOTE: I'm hearing from a depressingly large number of people who when they ask for metformin are put on drugs that are very expensive combinations of metformin and new or dangerous drugs like Onglyza, Januvia, or Actos. These drugs cost literally 15 times as much as plain, generic metformin and there is no research that suggests they result in better long term outcomes.

Indeed, the high risk of dangerous side effects from all of these new, expensive, and heavily marketed drugs suggests the opposite. But because the true dangers of a drug don't emerge until very shortly before they go off patent given the enormous clout that drug companies have, and the sneaky aggressive ways they market them, your doctor is all too likely to prescribe them.

In particular, I'm appalled at how many newly diagnosed people with Type 2 diabetes are now being given Kombiglyze XR, a combination of metformin and Onglyza. Onglyza has been shown by the very studies its manufacturer for the drug approval process to be less effective than Januvia, a drug in the same class, and to produce a higher rate of dangerous side effects. (Details HERE).

The side effects of Januvia are already disturbing. A doctor who would prescribe an Onglyza-metformin combo drug is a doctor who is strikingly ignorant about diabetes medications and who poses a danger to your health.


scall0way said...

I'm so glad I've begun to see recently a nurse practitioner who says her basic philosophy is that when a brand-new drug hits the market - run the other way! She prefers the tried and true. She has switched me to Armour for my hypothyroidism, believes completely in metformin and a low carb diet.

Stargazey said...

Thanks for this post, Jenny. It puts an important piece into the low-carb-for-health puzzle. said...


could you help me with this question?.

For different reasons I have to eat at work or traveling in places where the food options are very limited and my glucose one hour post meal passes 140 mg/dl.

Although I'm not diabetic some people in my familly are and I follow a low-carb diet to limit glucose spikes. However sometimes I have them because of bad food options.

My question is the following: is there any supplemet or drug that I can take to supress this occasional post meal spikes?. I've read something about American Ginseng; as for metforming, it might not work for ocassional use.


Jenny said...

Acarbose can prevent a blood sugar spike in a person with a decent second phase insulin response--but unfortunately the cost you pay for doing this is horrendous intestinal gas which, if you are traveling for business, makes it a very bad solution.

A small dose of Prandin will lower blood sugar at a specific meal, but too much can cause dangerous hypos so you would have to test it very carefully at home with many meals before trying it and it might be hard to get a prescription from a doctor if you have what doctors consider normal blood sugar.

The evidence that ginseng lowers blood sugar is a bit suspect since it appears to have been funded by people with a financial interest in ginseng. I have never heard of this effect from correspondents.

I have been told that fresh fenugreek leaves may have some effect, apparently by stimulating insulin secretion, but haven't tested it.

Portion control might be a better approach. If you have to eat high carb meals, eat less of what you are served, save what you don't eat and eat it later. Smaller portions will create smaller blood sugar rises. said...

Then, I might buy some pillls of fenugreek, as the only realistic option left, and verify with the glucometer if they work.

I agree small portions are the best idea, however many times they put sauces with very high sugar content, and one does not know.

Thanks a lot.

Anne said...

I had to have heart bypass surgery 11 years ago. I can't tell you what my glycosylated LDL was as that was never measured. I was given a glucose tolerance test but was told I did not have diabetes because my fasting level was in the 80's. What was ignored was my 2 hour level that was 202. It just wasn't high enough for my doctors to think it a problem.

Thank goodness for this site. For the past few years I have kept my blood sugar under 120(I would like it to be even lower) with diet alone. I hope this helps to heal my arteries.

Anni Macht Gibson said...

I am SO grateful to see this. I insist on doing everything I can to keep my BG's as close to Non Diabetic normals as the consternation of docs and other diabetics who look at my numbers and then groan at me and say "what are YOU complaining about" when my post prandial's inch toward 140! They look at me like I'm nuts... AND of course all the CDE's and Docs INSIST I test at 2 hours...not at 1 hr....

I am thin, not insulin resistant or antibody positive and have been on onglyza and a low/mod carb diet (under 70 per day) for 6 months since dx in Dec 2010. But my numbers have been creeping up despite my attempts at tight control and I expect tho I lowered A1C to 5.2 initially it will be up this last test done 6/10. I am going to ask my Endo about basal insulin when I see her on Friday next (Levemir).

Thank you for your writing and blogging...

Jenny said...


Have you had tests for the antibodies associated with diabetes? When someone with diabetes is thin and not able to control easily with carb restriction and oral drugs it is often the case that they have the slow developing form of Type 1 called LADA. Testing for C-peptide is also recommended as time goes on and your blood sugar control gets harder.