December 27, 2006

Recovering from Holiday Diet Mayhem

A quick scan of various diabetes support boards shows that people have either stopped posting completely, or they're posting messages along the lines of, "I can't believe I ate the whole thing!"

Yup. It's holiday time again.

Personally, I believe it is dangerous to be too perfect with any diet, because when people are utterly perfect, and never eat a single uncounted gram of carbohydrate, when they eventually DO crash off their diet plan, they tend to go off massively and end up harming their health and their weight. One day off plan won't do terrible things to your health, nor, for that matter, three days But if you're still eating your head off three weeks after Christmas, yes. You are in a world of hurt.

It's long been my belief that if you go off plan every so often you will learn how to get back on track, so you'll be more likely to handle times of excess like the holidays when temptations and the weight of family traditions make it extremely difficult to avoid diabetes-related food craziness.

There isn't any way around it. Unless you are one of those lucky people who have no emotional issues around food and could live happily on Purina People Chow, at times like Christmas, you either don't eat the special foods that have decades worth of warm associations and end up feeling like the Little Match Girl, standing in the cold, peering through the window at the more fortunate people enjoying the glorious family feast. Or you pig out and end up feeling like crap, because your body can't handle the carb-load and then spend the next week hiding from your diabetic friends out of embarrassment--hence the quietness on the diabetes discussion boards.

Fortunately, the official Diet Season starts January 2, and we can all stop thinking about party food until the Diet Season's Official End, which is of course, Super Bowl Sunday. Don't you love the irony of the way the supermarkets fill the "seasonal" shelves with diet food January 2, and then, 3 weeks later, replace them with Cheese filled Cheese Doodles and nacho sauce?

Meanwhile, for those of you who are relatively new to cutting back on carbohydrates, who did over do it on Christmas, here's a page I put together some years ago which helps you understand some of the physiological effects that can make you very hungry and feeling crazy when you try to get back to good dietary control. If you find yourself in a non-stop binge, reading this page may help you get back on track.

Crashing Off Your Low Carb Diet

Me, I'm going on a diet next week, until, of course, Super Bowl Sunday.

December 20, 2006

The Formulas equating HbA1c to Average Glucose Level Don't Work with Near Normal Blood sugars?

NOTE: Important New Information Added to this post in OCT 2007. Please scroll to bottom to read!

I got my new A1c result yesterday, the first in six months.

It was 5.5%.

During this period, my blood sugars have been significantly better than they had been for years. My fasting blood sugars have dropped about 20 mg/dl and my post-meal values have dropped by about 30 mg/dl. These changes have been measured many times using reference meals with known blood sugar outcomes.

In the past, my A1cs were almost always 5.7%.

The drop in A1c doesn't seem to capture the significant lowering of my blood sugars over this period.

The usual formula to estimate the relationship between A1c and mean plasma glucose was derived from the DCCT study.

That formula is:

Mean Blood Glucose = (A1c * 35.6) - 77.3

Applying this formula, an A1c of 5.5% is supposed to correspond to a mean plasma glucose of 118.5 mg/dl and an A1c of 5.7% is supposed to correspond to a mean plasma glucose of 125.6 mg/dl.

Neither of these values correspond to anything I have ever seen in my testing, and I test a lot and at many different times of day. My 30 day meter average, based on 150 measurements, has ranged between 98 and 103 during this period.

There is another, less cited formula that works better, at least for me. It is called "The Nathan Formula" it is:

Mean Plasma Glucose = (A1c * 33.3) -86

This formula yields a mean plasma glucose value of 97 mg/dl, which comes much closer to what my meter's 30 day average has looked like throughout this period.

Here's a calculator that will give you the Nathan Formula A1c/Mean Plasma Glucose equivalents:
A1c Calculator

However, I think the most important point is this: despite doctors' reliance on A1c it is not a particularly accurate measurement of what your blood sugars have been over the past three months. And not only that, the DCCT formula seem to work a lot better in people with very high blood sugars which is the group from which it was derived than they do those of us with near normal ones.

Here's a study published in the Journal of Family Practice that looked at the evidence connecting observed glucose measurements and A1c.

Does daily monitoring of blood glucose predict hemoglobin A1c levels?

The conclusions of this review include the following statements:

The relationship between HbA1c and blood glucose levels is such that blood glucose levels from the preceding 30 days determine about 50% of the total HbA1c. (10) This relationship may be altered by uremia, intake of vitamins C or E, and conditions that affect erythrocyte turnover. (11)

It remains unclear whether management strategies that focus on minimizing HbA1c levels are optimal for prevention of diabetic complications.

Although HbA1c levels correlate with the risk of some complications, aspects of glycemia not reflected in the HbA1c level, such as the heights of glycemic "excursions" from the mean, may independently affect the risk of complications of diabetes. (12) If so, quantitative analysis of day-to-day blood glucose levels might yield a better estimation of the risk of diabetic complications than HbA1c levels.

So what this means is this. The improvement I've made in my blood sugar by keeping my "excursions" (i.e. post meal values) around 110 instead of 140, is probably a lot more significant, healthwise, than the measily .2% improvement in A1c.

Keep this in mind if your A1c results don't match your observed daily testing results, and trust what you see on your meter not a cheering (or baffling) A1c.

UPDATE OCT 31, 2007

The American Association of Diabetes Glucose Trials has come up with a new and improved equation to relate A1c to mean glucose developed using "hundreds of thousands of readings" and CGMS data.

It is the A1C-Derived Average Glucose (ADAG) formula:

Measured in MMOL/L: Average Glucose = 1.583 * A1c - 2.52

Measured in mg/dl: Average Glucose = (1.583 * A1c - 2.52)*18.05

Using this formula:
4% = 69 mg/dl
5% = 97 mg/dl
6% = 126 mg/dl
7% = 155 mg/dl
8% = 182 mg/dl
9% = 211 mg/dl
10% = 239 mg/dl

In short, 1% of A1c equates to a difference in mean glucose of 29 mg/dl.

UPDATE: 4/23/2008.

I've put together a calculator that will convert A1c and average blood glucose using the new ADAG formula.

You'll find it at

December 13, 2006

ADOPT - Avandia "Wins" If You Ignore the Doubled Bone Fractures

Following the publication of the results of the ADOPT study, GlaxoKlineSmith, the makers of Avandia have been touting the finding that Avandia delayed the progression from "Monotherapy" i.e. taking one drug to taking additional drugs better than Metformin.

In the diabetes oral drug sweepstakes, they'd have you believe that Avandia is the "winner." What was missed in this interpretation was that this same study also found that women taking Avandia had twice as many bone fractures as those taking Metformin and three times as many as those taking glyburide.

Here's an excerpt from the story as it ran on several news sites. This one is from Yahoo News.

"After the five-year period of study, commonly reported adverse events across the treatment groups were oedema (rosiglitazone 14.1 percent; glyburide 8.5 percent; metformin 7.2 percent); weight gain (rosiglitazone 6.9 percent; glyburide 3.3 percent; metformin 1.2 percent); gastrointestinal side effects (metformin 38.3 percent; rosiglitazone 23.0 percent; glyburide 21.9 percent); and hypoglycaemia (glyburide 38.7 percent; metformin 11.6 percent; rosiglitazone 9.8 percent).1

[emphasis mine] Recent further analysis showed a lower rate of fractures reported as adverse events in women taking glyburide or metformin versus rosiglitazone (glyburide 3.5 percent; metformin 5.1 percent; rosiglitazone 9.3 percent), most commonly involving fractures of the foot and upper limb bones.1 There was no observed difference among treatment groups in the number of fractures reported in men.1"

This says that women on Avandia (rosiglitazone) had twice as many fractures as those on Metformin and almost 3 times as many as those on Amaryl (glyburide.)

The total number of fractures was not huge, but this finding takes on more importance when linked to a previous study, published in November that also found that Avandia and Actos increased the incidence bone fractures in older women in nursing homes who had been taking it.

Here is a report of that study, as reported in the Diabetes in Control newsletter: TZD’s Can Increase Bone Loss in Type 2 Women

The reason why this might be happening as reported in the nursing home study was that Avandia apparently disrupts the parathyroid hormone that regulates calcium.

This is very disturbing because it may mean that in people who are taking Avandia, it is very slowly and without anyone observing it causing bone to be remodeled in a way that will not become obvious for years to come but will eventually ruin lives.

By the time the bone changes do become obvious, the old ladies who have taken Avandia for a decade will begin to break their hips and die, but it will be too late. Their bones will have already been weakened.

That the drug manufacturer completely fails to mention this new, and dangerous side effects in its hail of advertising to physicians and its press releases to the public is very troubling.

If nothing else, if you have been taking Avandia for any length of time, insist on having your doctor order a bone scan and have it repeated every couple years to be sure that that you aren't developing early signs of osteoporosis that won't otherwise be detectable for many more years. Osteoporosis causes fractures in older people that lead to death in 25% of all cases in people over age 50 and more in the more elderly.

December 5, 2006

Some Inspiring Stories

I answered a newbie on another board who had just been diagnosed, mentioning that I knew many people who had been diagnosed with blood sugars far worse than hers who had been able to get completely normal blood sugars.

The lady wrote back that reading that message had made her burst into tears which had not happened even when she'd gotten her diagnosis.

Only when she could believe it wasn't a sentence of death, or blindness, or amputation, could she begin to think about this huge change in her life!

With that in mind, I spent the day combing through 5 years of newsgroup messages, looking for inspirational tales. I've extracted excerpts from postings where people have reported that they have managed to get back to normal blood sugars often from very high initial numbers. (Normal in this case is defined as having an A1c of under 6%, or what people in the newsgroup used to call "The 5% Club.")

The people quoted in these messages have used a variety of techniques to get to normal numbers, cutting carbs, testing blood sugar after meals, medications, exercise, and insulin. What they have in common is that they got there.

Here's the link to some of these stories. If you've been needed some inspiration I hope you'll find it here. And if you have an inspiring story of your own, please let me hear it! - The Five Percent Club