T Nation

HbA1C and Mortality Data for Non-Diabetics


#1


I wanted to present this info: http://carbsanity.blogspot.com/2013/09/low-hba1c-is-as-bad-or-worse-than-high.html

In case the website is not allowed I will post an image.

The data is for NON diabetics.

The mortality likelyhood is modelled by 8 different variants of 3 models for non-diabetics.

The lowest mortality rate among non-diabetics is the group with HbA1C between 5.0 and 5.4, NOT the groups lower than 5.0 as Bernstein believes. The mortality rate of those with an HbA1C between 4.5-4.9 is higher than that of those between 5.0 and 5.4 in all of the model variants. The mortality rate of those lower than 4.5 is as high as for those above 6.0.

the point is that the lowest mortality rate is NOT skewed above 5.0 because of deaths due to diabetic hypoglycemia, because this study does not include diabetics. It COULD be slightly skewed due to very low HbA1C's being related to anemia, but the point remains that there is no evidence that anybody lives longer by taking their HbA1C down below 5.0. Model 2e though I believe accounts for anemia and still shows higher mortality prediction rate at 4.5-4.9 than at 5.0-5.4

Since the 4.5-4.9 group has a little lower increased mortality than the 5.5-5.9 group, it looks to me like the absolute bottom of the graph of mortality to HbA1C would bealmost, but not quite at the very bottom of the 5.0-5.4 group, say 5.1.

It is odd that the groups with HbA1C below 5.0 had higher average mortality but a broader range of mortality that extended from lower than that of those at 5.0-5.4 to higher than that. This might indicate that there is a division between non-diabetics who are below 5.0 into those who are below 5.0 due to pathological reasons.

I will also point out that another study cited shows that ALL CAUSE mortality for non-diabetics is lowest for on the graph for FASTING blood sugar of 99 which is considered by many doctors to be a sign of likely future diabetes. The study did exclude those who were actually diabetic though.

I wanted to add that Dr. Bernstein was clearly ahead of his time, or even the current times with regard to diabetics, but he personally advocates that a normal fasting blood sugar is 83, and an A1C should be below 4.6, and possibly as low as 4.2 (which he claims to have reached). I think he is a genius, and did took the best possible approach for diabetes when insulin was slow and blood sugar tests were slow and not up to the minute. Lower insulin doses for lower carbs reduce the margin of error that can lead to killer hypos, but IF an insulin using diabetic can avoid hypos the evidence still supports the best health in the low end of the 5.0-5.4 HbA1C range, and if someone does not become diabetic, the best fasting blood sugar (lowest mortality) is in the 90s, and clearly NOT in the 80s.


#2

Those fasting blood sugar numbers are surprising.


#3

Thank you for posting the study!

The data for mid-low HbA1C though is not showing greater mortality. Too much variability relative to the number of subjects (for example, for the 4.5 to 4.9 group, the 95% confidence interval includes anywhere down to 68% for the mortality, which would be less.)

The paper ( http://circoutcomes.ahajournals.org/content/3/6/661.long ) seems to claim statistically significant findings only for A1C < 4.0 and AC1 >= 5.5.


#4

That was what I thought. My interpretation or "guess" is that there are people who are in the 4.0-5.0 range who are there for the right reasons and those who are there for the wrong reasons (anemia, cancer, celiac, possibly excessive exercise and or under nourishment/eating disorder, hepatitis or drug use. I knew diabetics who had 4.5 A1Cs because they were anemic and their blood cells died to fast to get glycated. The 4.0-4.5 group I believe had the highest rate of IV drug use and hepatitis. Hepatitis affects the mortality rate but isn't really CAUSED by low blood sugar. So I think that if someone is otherwise healthy, there is evidence that they may live longer with A1C under 5.0. Notice how small the 95% interval is for the 5.0-5.4 group. It would easily be possible that half of the 4.5-4.9 group has lower mortality, and that another half who are there via pathology have a much higher mortality.

Also stress can raise blood sugar, but at some point you become catecholamine resistant and may have a drop in fasting blood sugar due to extensive chronic stress.


#5

Maybe a dumb question, but couldn't but couldn't lower average and fasting glucose levels be a sign of some sort of impairment in fatty acid metabolism and unhealthy?

On a side, I was also reading recently that PUFAs may be the bigger factor in insulin resistance in very low carb/high fat diets, not saturated fat. Which seems to mean if keep your PUFAs low, insulin resistance in the low carb diets may not be a problem. Either of yall know anything about this?


#6

I know that beta cell death is related to oxidative damage which comes largely from having LDL/triglycerides that have oxidized PUFAs, and not at all from saturated fat.

A lot of diabetes "studies" have tried to show that dietary saturated fat reduces insulin sensitivity after a meal, and this may be true, but may largely be due to obese individuals overeating calories, and also having larger amounts of fat around the muscle.

But as to your specific question, I would say NO, the metabilic insulin resistance from a low carb diet seems, in my research to be independent of fat intake at all (because your FASTING blood sugar tends to be higher on a low carb diet) even after quite a long fast.

But like I said, I certainly believe that PUFAs knock out beta cells. High PUFA and high sugar are a double edged sword. The third is EXCESSIVE aerobic activity. The fourth is high blood pressure. Blood pressure correlates more to the complications of high blood sugar than does blood sugar.

I want to make it clear that I define insulin resistance as the body not responding optimally to the insulin that is secreted. I define insufficient insulin response to blood sugar to not be insulin "resistance" or insensitivity, but pancreatic insufficiency which is not insulin insensitivity, but YOUR insensitivity to glucose, or ability to deal with it. The two terms get totally mixed up here.


#7

To follow up on this, I think the data is clear than while having an A1C under 4.5 CORRELATES to higher mortality and health issue, for a otherwise healthy person to be at 4.5 indicates lower mortality and complications than being above 5.0, and being between 4.0 and 4.5 may be even better for someone who does not have a low A1C for pathological reasons. My data interpretation comes from the fact that individuals in the 4-4.5 group had the best mortlity coefficient while others were worse than normal. Individuals in the 4.5-4.9 group had better than the best coefficients in the 5.0-5.5 group even though the average was a little worse.

And I think the reason that the average mortality goes up is because low blood sugar can be caused by the following pathologies:

A low blood glucose level (hypoglycemia) may be seen with:

Adrenal insufficiency
Drinking excessive alcohol
Severe liver disease
Hypopituitarism
Hypothyroidism
Severe infections
Severe heart failure
Chronic kidney (renal) failure
Insulin overdose
Tumors that produce insulin (insulinomas)
Starvation
Deliberate use of glucose-lowering products