June 7, 2008

Australian Study: 6.5% is NOT Normal and Sulfs aren't Great for Your Heart

This is a very brief post about the Australian study you'll be hearing a lot about this week, ADVANCE. That's the one that found that lowering blood sugar to "normal" did not prevent heart disease in people with diabetes. I've gotten some mail asking me to comment on it, so here goes:

1. Normal blood sugar in this study was defined as an A1c of 6.5%. This represents an average blood sugar of 140 mg/dl (7.7 mmol/L). With the technique used to lower blood sugar in the Australian study that average was most likely achieved by having the blood sugar seesaw between 85 and 200 mg/dl.

Looking at the graphs relating heart disease to blood sugar you can easily see that the 6.5 A1c is far from normal. Studies show that with ever 1% rise over 4.7% heart disease risk increases greatly. You can check out some studies linking A1c to heart disease in people with and without diabetes HERE.

2. The Australian study lowered blood sugar using sulfonylurea drugs. These drugs have long been known to be associated with an increased risk of heart attack. In the U.S. every sulfonylurea drug (Amayrl, Glipizide, etc) carries a black box warning that specifically cites the increased risk of heart disease found with some members of this class of drugs.

3. The people in this study, like people with diabetes all over the world had undiagnosed prediabetes and even undiagnosed Type 2 diabetes for decades before diagnosis. The studies I cited above show that even prediabetic blood sugars are linked to heart disease.

So heart disease in people with diabetes may be very well established in their bodies at the time of diagnosis. Unfortunately, in both the large studies of lowering blood sugar in the news this week (ADVANCE and ACCORD, the study that used Avandia and Byetta along with the high carb diet) the technique used to lower the blood sugar was a high carbohydrate/low fat diet combined with high doses of drugs that are not good for the heart. It is well known that the high carb/low fat diet pushes all the cardiovascular markers in the wrong direction.

4. There is no large scale study of what happens to people with diabetes who lower their carbohydrate intake dramatically and use the smallest doses needed of only metformin (which appears cardio-protective) and insulin to regain control.

If you follow the advice found at http://alt-support-diabetes.org/newlydiagnosed.htm
you will flatten your blood sugar and avoid ever going over 140 mg/dl, rather than having a blood sugar that averages 140 mg/dl and goes much higher for hours ever day. This approach has helped many of us online who share our diabetes experiences avoid heart disease if we did not have it already and heart attack if we do.

5. The Australian study did show a very significant drop in kidney disease occurring when the A1c dropped to 6.5%. We will have to wait for the publication of the results to see the actual details of this study and what else it might have found that wasn't reported in the Newsbytes for Dummies health reports.

P.S.: I'm going to he having some fairly major surgery this next week (nothing scary, just something badly needed) so the blog will be on hiatus for the next week or two. When I'm back I'll comment at length on the research and drug company puffery presented at the ADA annual meeting.

See you then!


Nicky said...

I got all excited by ADVANCE until I saw the meds they were on, and the fact that again they were not able to moderate their diet as a result of testing :(

Hope the op goes well, and your recovery is fast.


nonegiven said...

Good luck. I hope your hospital experience is much better than the previous one.

Sarah said...

Thanks for another excellent post! Best wishes for a speedy recovery and uneventful hospital stay with YOU in control of your blood testing/treatment while an in-patient.


Anne said...

Thanks for posting about the Australian study.

Wish you well during surgery and a speedy recovery.