I've been reading up on mitochondria this month, in the writings of Nick Lane, Power, Sex, Suicide: Mitochondria and the Meaning of Life, and Oxygen: The Molecule That Made the World. There was a lot of interesting information in both books, but because at times Lane writes in a confused way about the relationship of diabetes and mitochondrial dysfunction, I became curious about what is actually known about mitochondrial failure and diabetes and started reading up on the subject.
It turns out that there is a distinct genetic form of diabetes caused by the A3243G mutation in the mitochondrial DNA-encoded tRNA(Leu,UUR) gene. It causes an adult onset form of diabetes that can be misdiagnosed as either Type 1 or Type 2 depending on how late the onset is. Some people get it in their 20s, while others only develop it in middle age. The average age of onset is 38 years. Whatever the time of onset, 100% of those who have this gene will eventually become diabetic, with a form of diabetes characterized by failure to secrete insulin, rather than insulin resistance.
Like all the genetic forms of diabetes, this is another case where the actual expression of the gene defect can range from very mild to severe. Some people who carry it won't develop diabetes until they are in their 60s, while others may get it in their teens and be misdiagnosed as Type 1 (though the person with it will not show the characteristic antibodies associated with autoimmune Type 1.) The actual percentage of mitochondria carrying the mutation in various tissues will vary from person to person diagnosed with it, and that may have something to do with the severity of the diabetes, as well as whether other damaging effects of the gene are present (discussed below.)
A very severe condition caused by this gene mutation is called MELAS syndrome and reading about its symptoms can be scary, as they include stroke, and a shortened life. But the good news is that now that gene testing is more widely available, scientists are now finding that many people with the same mutation have far less severe manifestations that go undetected until they are gene tested, though these other carriers may have various health problems that seem like the usual wear and tear that are actually byproducts of the gene.
Also, and very interestingly, people with this gene defect, who tend to be thin and at times shorter than their peers, prior to becoming diabetic will have completely normal C-peptide and glucose tolerance tests. However as the gene expresses in their beta cells it apparently causes the mitochondria in the beta cells to fail, leading to the death of the beta cells.
This gene is found in varying frequencies in different ethnic populations. It was found in almost 3% of a Japanese diabetic population, and in about 1% of a group of Dutch people with diabetes. The incidence was lower in those participating in the UKPDS, and in a French population--roughly .5%.
Because mitochondrial genes are passed only from the mother, the family pattern of this genetic form of diabetes appears strictly in the maternal line. Men can get it if their mothers have it, but they cannot pass it on to their children.
This gene defect also appears occasionally spontaneously, so it is possible to have it without a family history but this is very rare.
This gene defect also causes hearing loss in the higher frequency ranges which often becomes evident shortly before the diabetes appears. For that reason this kind of diabetes is also called MIDD (Maternally Inherited Diabetes with Deafness.)
People with this gene may also have a hard-to-detect problem with their heart muscles--asymptomatic cardiomyopathy--which makes it very important that they avoid Avandia and Actos, which have been proven to increase the risk of heart failure in people who take them. The sulfonylurea drugs except gliclazide are also problematic since they also seem to have a negative effect on the heart.
Changes in retinal pigmentation also present in many carriers of the A3243G mutation and they may be more prone than others to develop retinopathy, though it appears that controlling blood sugar will lessen the risk of this happening. Other symptoms which are related to the gene defect can include problems with the digestive tract including diarrhea, obstruction, and severe heartburn.
This gene defect can also cause problems with kidneys that will show up as protein in the urine but are not necessarily linked to high blood sugars, as is typical in diabetes, but are another outcome of the failing mitochondria.
In some people with this gene defect there are other manifestations of mitochondrial failure throughout the body including the inability to tolerate exercise and a frequent migraines. A smaller number have strokes at a young age. This is one reason why you would want to be screened for this gene if you do have the history of diabetes running down the maternal line of your family in conjunction with deafness.
Because mitochondrial failure can cause a rise in lactic acid, people with this form of diabetes should not take metformin as they are at risk for lactic acidosis.
If your family and personal history are suggestive of this kind of diabetes, demand that it be ruled out. It is very possible that your family doctor will NOT have heard of it, so you may have to educate him or her. If you encounter resistance (such as the doctor responding to your showing him one of the articles below by saying, "Where did you earn your M.D.?") find another doctor. This kind of diabetes because it may come with other organ problems requires that you find the support of a very good, up-to-date medical team.
The appropriate treatment for mitochondrial diabetes is insulin, as it brings about the progressive loss of beta cells over time, so it won't be fully controlled by diet. The better you control your blood sugars, the less stress you are putting on those beta cells that remain, so it's likely that very tight control--as close to normal as possible--will have some effect, and of course, it will help prevent the development of the classic diabetic complications.
I have heard from one person diagnosed with MELAS whose diabetes was being controlled with insulin but who was having trouble with her control. She reported that following the "Test test test" strategy this site recommends was helpful for improving her control. You can read about it HERE.
Though I read recommendations online that it is possible to treat milder versions with sulfonylurea drugs, this is probably a bad idea given the recent findings (published after these articles were written) that sulfonylurea drugs can harm the heart.
If you have the symptoms of this form of diabetes you should get your heart checked out by a talented cardiologist--ideally one who practices in a teaching hospital who might have heard of this syndrome, rather than one of the hacks who practices out of a community hospital and prescribes statins to everyone who walks through the door.
As is too often the case with oddball forms of diabetes, most of what you find in scanning the research is diagnostic, rather than information about how to treat the condition. That is probably because it is rare and no one will get rich treating it. If you do have this kind of diabetes it is likely that like everyone else with some form of diabetes your overall health will be better if you keep your blood sugar as close to normal as possible, which even with insulin usually requires keeping a close eye on carbohydrate intake and ratcheting it down until you are avoiding the blood sugar spikes over 140 mg/dl (7.7 mmol/L) that are known to cause the classic diabetic complications.
RESOURCES FOR LEARNING ABOUT MITOCHONDRIAL DIABETES
Mitochondrial Diabetes Molecular Mechanisms and Clinical Presentation.
J. Antonie Maassen et al.Diabetes .53.2007.S103 Diabetes February 2004 vol. 53 no. suppl 1 S103-S109 doi: 10.2337/
Epidemiology and Treatment of Mitochondrial Disorders. Patrick M Chinnery, et al. American Journal of Medical Genetics (Semin. Med. Genet.) 106:94±101 (2001)
Markedly different clinical features in 2 diabetes mellitus patients with extremely high tissue levels of the mitochondrial DNA A3243G mutation. Shinji Harihara. Gerontologia (2008) Volume: 54, Issue: 3, Pages: 168-172
Protean Phenotypic Features of the A3243G Mitochondrial DNA Mutation. Petra Kaufmann et al. Archive of Neurology VOL 66 (NO. 1), JAN 2009
December 26, 2011
December 19, 2011
Another Dangrously Misleading Study Promoting High A1cs as Healthy
A presentation given at the recent 44th annual meeting of the American Society of Nephrology claims that patients on dialysis have better outcomes when they have higher A1cs. As reported in Medscape, the chief researcher says, "The range from 6% to 9% seems to be the lower range of risk. There's even an impression that you could say that from 7% to 9% is the lowest risk."
You can read the report of the presentation here. It also got some play in the medical news and newsletters directed to doctors and appears summarized on quite a few diabetes sites. The Medscape article gives the best summary. Signing up is free:
Medscape:Diabetics on Dialysis Do Better With Higher Hemoglobin A1c.
It is all too likely that busy family doctors who encounter this information will add it to the rest of the bad research that has convinced them that it's dangerous for people with Type 2 Diabetes to lower their blood sugars to normal levels. (You can read about how misinterpreted studies have led this toxic recommendation HERE.)
To understand the real meaning of the paper given at American Society of Nephrology you have to know that other research looking into the blood sugars of people on dialysis has found that because of the impact of dialysis on their red blood cells, the A1cs of people on dialysis do not correlate to their blood sugars.
In a published review of the research that discovered the inapplicability of the A1c test to people on dialysis, the author writes
HbA1c Inaccurate in Diabetic Patients on Hemodialysis, Study Says Hogan, Michelle. Nephrology Times: April 2008 - Volume 1 - Issue 4. doi: 10.1097/01.NEP.0000334255.74897.99
The crucial findings of this study were:
Test your blood sugar 1 hour after eating. If your level is under 140 mg/dl (7.7 mmol/L) you are in the range that research suggests will avoid diabetic complications. If you are staying over 140 mg/dl (7.7 mmol/L) for more than an hour or two you are raising your risk of complications. The more time spent over that level, the more likely it is that you are damaging your organs.
The damage doesn't start immediately, and most of us will see occasional readings over that level from time to time that, if they are isolated events, aren't likely to cause damage. But if we are seeing them every day, it's time to take action.
If you are on dialysis, you will want to rely on what you see when you test your blood sugar after meals, not the A1c, to ensure that you aren't worsening whatever other diabetic complications you already have by maintaining damaging high blood sugar levels.
And if you aren't on dialysis and want to keep your nerves, kidneys, eyes and heart healthy, don't let any doctor tell you that it's dangerous to lower your A1c below 6.5%. The evidence suggests that it is not only safe, but very healthy to lower your blood sugar to normal levels, as long as you aren't doing it using Avandia, Actos, Glipizide or Glimiperide all of which have been shown to damage the heart.. The one other "dangerous" way to lower blood sugar is to use insulin in such a way that you balance high blood sugars with hypos. If you are using insulin but never see hypos below 60 mg/dl (3.3 mmol/L) you have nothing to fear.
If you avoid these known dangerous drugs and use carb restriction, metformin, and/or insulin dosed correctly to lower your blood sugar, especially if you start close to diagnosis (or in the pre-diabetic stage) before long term exposure to high blood sugars have damaged your heart, nerves, and blood vessels, your long term outlook should be very good.
And if your doctor disagrees, find a new doctor. Only doctors whose knowledge of diabetes is gleaned only from dumbed down one-paragraph newsletter summaries--or from perky drug company reps who encourage doctors to keep patients at high A1cs because their expensive new drugs only achieve higher than normal A1cs--believe that lowering A1c to normal levels is dangerous.
You can read the report of the presentation here. It also got some play in the medical news and newsletters directed to doctors and appears summarized on quite a few diabetes sites. The Medscape article gives the best summary. Signing up is free:
Medscape:Diabetics on Dialysis Do Better With Higher Hemoglobin A1c.
It is all too likely that busy family doctors who encounter this information will add it to the rest of the bad research that has convinced them that it's dangerous for people with Type 2 Diabetes to lower their blood sugars to normal levels. (You can read about how misinterpreted studies have led this toxic recommendation HERE.)
To understand the real meaning of the paper given at American Society of Nephrology you have to know that other research looking into the blood sugars of people on dialysis has found that because of the impact of dialysis on their red blood cells, the A1cs of people on dialysis do not correlate to their blood sugars.
In a published review of the research that discovered the inapplicability of the A1c test to people on dialysis, the author writes
We expected maybe the hemoglobin A1c would be slightly impacted by the shortened red cell survival when we went into the study, but the results were shocking to us in that the hemoglobin A1c levels were significantly lower to where they would affect patient care and outcomes.You can read this report here:
HbA1c Inaccurate in Diabetic Patients on Hemodialysis, Study Says Hogan, Michelle. Nephrology Times: April 2008 - Volume 1 - Issue 4. doi: 10.1097/01.NEP.0000334255.74897.99
The crucial findings of this study were:
Compared with patients who did not have kidney disease, patients with end-stage renal disease had higher mean serum glucose concentrations-172 mg/dL vs 146 mg/dL-and higher percent glycated albumin-18.7% vs 15.3%-but lower hemoglobin A1c-6.8% vs 7.3%.There is another test that gives a better idea of blood sugar control over a longer time period, but it isn't available in the U.S.. What is available is testing with your blood sugar meter--which is more accurate in predicting health outcomes than the A1c ever was.
For a glucose level of 150 mg/dL, for example, hemoglobin A1c was about 6.5% in the dialysis group but 7.5% in the normal renal function group.
Test your blood sugar 1 hour after eating. If your level is under 140 mg/dl (7.7 mmol/L) you are in the range that research suggests will avoid diabetic complications. If you are staying over 140 mg/dl (7.7 mmol/L) for more than an hour or two you are raising your risk of complications. The more time spent over that level, the more likely it is that you are damaging your organs.
The damage doesn't start immediately, and most of us will see occasional readings over that level from time to time that, if they are isolated events, aren't likely to cause damage. But if we are seeing them every day, it's time to take action.
If you are on dialysis, you will want to rely on what you see when you test your blood sugar after meals, not the A1c, to ensure that you aren't worsening whatever other diabetic complications you already have by maintaining damaging high blood sugar levels.
And if you aren't on dialysis and want to keep your nerves, kidneys, eyes and heart healthy, don't let any doctor tell you that it's dangerous to lower your A1c below 6.5%. The evidence suggests that it is not only safe, but very healthy to lower your blood sugar to normal levels, as long as you aren't doing it using Avandia, Actos, Glipizide or Glimiperide all of which have been shown to damage the heart.. The one other "dangerous" way to lower blood sugar is to use insulin in such a way that you balance high blood sugars with hypos. If you are using insulin but never see hypos below 60 mg/dl (3.3 mmol/L) you have nothing to fear.
If you avoid these known dangerous drugs and use carb restriction, metformin, and/or insulin dosed correctly to lower your blood sugar, especially if you start close to diagnosis (or in the pre-diabetic stage) before long term exposure to high blood sugars have damaged your heart, nerves, and blood vessels, your long term outlook should be very good.
And if your doctor disagrees, find a new doctor. Only doctors whose knowledge of diabetes is gleaned only from dumbed down one-paragraph newsletter summaries--or from perky drug company reps who encourage doctors to keep patients at high A1cs because their expensive new drugs only achieve higher than normal A1cs--believe that lowering A1c to normal levels is dangerous.
November 30, 2011
For Colorectal Cancer It's the Blood Sugar NOT The Insulin Level That Counts
A recently published study based on data from the Womans Health Initiative (WHI) sheds light on a question many of us have wondered about: Is the higher incidence of cancer among people with Type 2 caused by higher insulin levels (or, perhaps injected insulin) or something else?
The study was conducted by a team at The Albert Einstein College of Medicine, which some of you may remember is where Dr. Bernstein earned his M.D.. It has through the years done several low carb studies, too.
The study is summarized here:
Science Daily: High Blood Sugar Levels in Older Women Linked to Colorectal Cancer
The actual abstract is found here:
A longitudinal study of serum insulin and glucose levels in relation to colorectal cancer risk among postmenopausal women. G C Kabat et al. British Journal of Cancer , (29 November 2011) | doi:10.1038/bjc.2011.512
From the abstract we learn that in a group of 4902 middle aged women who were tracked for 12 years, about 1.6 percent developed colorectal cancer. They had had their fasting blood sugar and fasting insulin measured at the beginning of the study and occasionally through the study. This study found that women whose fasting blood sugar was over 99.5 mg/dl (5.53 mmol/L) at the beginning of the study had a greater risk of developing colorectal cancer than those with blood sugars under 89.5 mg/dl (4.98 mmol/L). The relationship held true for subsequent blood tests too.
However--and this is what is interesting about this study--there was no relationship between these women's fasting insulin levels or the calculated HOMA values (which are believed to measure insulin resistance) and their risk of getting this cancer.
So this data would suggest that it is the high blood sugars, not the high insulin which promotes the cancer.
Before you panic because your fasting blood sugar is over 99.5 mg/dl (as is the case with many of us thanks to dawn phenomenon) remind yourself of this: from what we can see in other contexts, it isn't actually mildly elevated fasting blood sugars that damage our bodies. We see the correlation between fasting sugars and complications in studies because in people eating high carbohydrate diets, mildly elevated fasting blood sugars almost always go hand in hand with significantly elevated post meal sugars. Especially in women, who may be diabetic by glucose tolerance test for up to a decade before they would be diagnosed using a fasting glucose test. (You can see the data backing this up HERE.)
So a woman with a fasting sugar of 105 mg/dl, for example, when she eats her morning bagel with jelly, along with a sweetened latte, may easily reach a blood sugar that approaches 200 mg/dl even if it resolves fairly quickly due to a near-healthy second phase insulin release. But if diabetic you should wake up with a blood sugar of 105 mg/dl and eat an egg and bacon for your breakfast with no carbs, you may easily end up with a blood sugar of 95 an hour later, which suggests you would have a similar health outcome to a completely non-diabetic woman with a fasting blood sugar of 89 mg/dl who ends up at 95 mg/dl an hour after eating her breakfast.
It's also worth noting that the statistical measure the study calculated was "risk" not incidence--and that risk is a statistical artifact that magnifies numbers to provide a more dramatic impact. The actual increase in incididence due to elevated blood sugar was likely around 5 cases per thousand or .5%.
But on the positive side, the fact that even after using magifying statistical techniques like "risk" the researchers couldn't find the expected connection between fasting insulin levels, HOMA, and cancer gives us one more, intriguing, piece of data to answer the quesion, "Do people with diabetes get cancer because of high insulin levels (injected or natural) or because of high blood sugars?" Here at least, it looks like the answer is, as is the case with all the other diabetic complications, "It's the blood sugars, stupid!"
This is very good news because our insulin levels are very hard to control and insulin resistance may be genetic and not something we can lower. Even many devout low carbers with Type 2 continue to be insulin resistant no matter what they weigh (based on how much insulin they have to inject to lower their blood sugars.) But insulin resistant or not, we can control our blood sugars--often most effectively with insulin--and if the conclusion of this study is reinforced by findings in other studies, we may be able to relax about the potential impact on cancer of our injecting insulin to control those blood sugars.
One last note: If you have had years of exposure to higher than normal blood sugars, you might be interested in knowing that Metformin has been shown to suppress the growth of existing early colorectal growths in people without diabetes. Read about that HERE.
Though researchers often state that metformin inhibits cancer due to its effect on lowering insulin, this is just a guess. The belief that it is high insulin levels that cause a greater incidence of cancer among people with diabetes is far from proven and that theory is exactly the belief this study debunks.
In fact, there is evidence emerging that metformin's anti-cancer properties are independent of its effect on insulin and have to do with its ability to suppress TORC1, a cell growth factor. (For example, see THIS STUDY.)
NOTE: Since posting this I have reviewed the full text of the study and see nothing to change the conclusions discussed here. It looks very well conducted, involved people from various well-respected public health departments in universities and medical schools, and gives no hint of corporate meddling.
The study was conducted by a team at The Albert Einstein College of Medicine, which some of you may remember is where Dr. Bernstein earned his M.D.. It has through the years done several low carb studies, too.
The study is summarized here:
Science Daily: High Blood Sugar Levels in Older Women Linked to Colorectal Cancer
The actual abstract is found here:
A longitudinal study of serum insulin and glucose levels in relation to colorectal cancer risk among postmenopausal women. G C Kabat et al. British Journal of Cancer , (29 November 2011) | doi:10.1038/bjc.2011.512
From the abstract we learn that in a group of 4902 middle aged women who were tracked for 12 years, about 1.6 percent developed colorectal cancer. They had had their fasting blood sugar and fasting insulin measured at the beginning of the study and occasionally through the study. This study found that women whose fasting blood sugar was over 99.5 mg/dl (5.53 mmol/L) at the beginning of the study had a greater risk of developing colorectal cancer than those with blood sugars under 89.5 mg/dl (4.98 mmol/L). The relationship held true for subsequent blood tests too.
However--and this is what is interesting about this study--there was no relationship between these women's fasting insulin levels or the calculated HOMA values (which are believed to measure insulin resistance) and their risk of getting this cancer.
So this data would suggest that it is the high blood sugars, not the high insulin which promotes the cancer.
Before you panic because your fasting blood sugar is over 99.5 mg/dl (as is the case with many of us thanks to dawn phenomenon) remind yourself of this: from what we can see in other contexts, it isn't actually mildly elevated fasting blood sugars that damage our bodies. We see the correlation between fasting sugars and complications in studies because in people eating high carbohydrate diets, mildly elevated fasting blood sugars almost always go hand in hand with significantly elevated post meal sugars. Especially in women, who may be diabetic by glucose tolerance test for up to a decade before they would be diagnosed using a fasting glucose test. (You can see the data backing this up HERE.)
So a woman with a fasting sugar of 105 mg/dl, for example, when she eats her morning bagel with jelly, along with a sweetened latte, may easily reach a blood sugar that approaches 200 mg/dl even if it resolves fairly quickly due to a near-healthy second phase insulin release. But if diabetic you should wake up with a blood sugar of 105 mg/dl and eat an egg and bacon for your breakfast with no carbs, you may easily end up with a blood sugar of 95 an hour later, which suggests you would have a similar health outcome to a completely non-diabetic woman with a fasting blood sugar of 89 mg/dl who ends up at 95 mg/dl an hour after eating her breakfast.
It's also worth noting that the statistical measure the study calculated was "risk" not incidence--and that risk is a statistical artifact that magnifies numbers to provide a more dramatic impact. The actual increase in incididence due to elevated blood sugar was likely around 5 cases per thousand or .5%.
But on the positive side, the fact that even after using magifying statistical techniques like "risk" the researchers couldn't find the expected connection between fasting insulin levels, HOMA, and cancer gives us one more, intriguing, piece of data to answer the quesion, "Do people with diabetes get cancer because of high insulin levels (injected or natural) or because of high blood sugars?" Here at least, it looks like the answer is, as is the case with all the other diabetic complications, "It's the blood sugars, stupid!"
This is very good news because our insulin levels are very hard to control and insulin resistance may be genetic and not something we can lower. Even many devout low carbers with Type 2 continue to be insulin resistant no matter what they weigh (based on how much insulin they have to inject to lower their blood sugars.) But insulin resistant or not, we can control our blood sugars--often most effectively with insulin--and if the conclusion of this study is reinforced by findings in other studies, we may be able to relax about the potential impact on cancer of our injecting insulin to control those blood sugars.
One last note: If you have had years of exposure to higher than normal blood sugars, you might be interested in knowing that Metformin has been shown to suppress the growth of existing early colorectal growths in people without diabetes. Read about that HERE.
Though researchers often state that metformin inhibits cancer due to its effect on lowering insulin, this is just a guess. The belief that it is high insulin levels that cause a greater incidence of cancer among people with diabetes is far from proven and that theory is exactly the belief this study debunks.
In fact, there is evidence emerging that metformin's anti-cancer properties are independent of its effect on insulin and have to do with its ability to suppress TORC1, a cell growth factor. (For example, see THIS STUDY.)
NOTE: Since posting this I have reviewed the full text of the study and see nothing to change the conclusions discussed here. It looks very well conducted, involved people from various well-respected public health departments in universities and medical schools, and gives no hint of corporate meddling.
November 12, 2011
Another Book?
Now that I've discharged my obligations under my contract with the publisher of my novels, I'm considering what to do next. And that is leading me to ask what I could do that would be of use to the people who visit http://Bloodsugar101.com and this blog.
Publishing the book version of the site has taught me that most people still find books a better way to study a complex topic, even when the information in the book is also available on a web site.
This has been a pleasant surprise, as has been the steady stream of fan mail that the book generates. There's no question that people who read the book learn far more than people who visit the site, if for no other reason than that most people who visit the site only read a couple pages before leaving.
So that raises the question: Should I write another book? And if I do, what should be its subject?
I have some ideas of my own, but before I plunge in I'd love to hear some feedback from you about what topics you would like to learn more about. I'd also like to know, iIf you read my book, Blood Sugar 101, if you thought there was something important that was left out.
Keep in mind, of course, that there are many topics I'd love to be able to write about that are too poorly researched to justify a book. For example, I have spent quite a lot of time looking into the physiology of weight loss, but the more research I read, the less conviction I have that any of it can be trusted. The quality is just abysmal and unlike the publications about diabetes, my many hours of study did not turn up any overlooked gems.
On the other hand, very little has come up that is new since I wrote Blood Sugar 101. In fact, it is rather depressing just how little that would be of any use to someone trying to preserve their health.
But though I might feel that way, life has taught me that one problem with making yourself into an "expert" in some topic area is that the things that bore me after a decade of daily attention to the topic may be exciting to people who haven't soaked their head in this stuff for years.
So I welcome your feedback. What kind of book--if any--do you think would be most useful to a reader who has already read Blood Sugar 101? Click on the comment link below and share your thoughts with me. The only thing I will ask is that you keep your comments on the topic I've sketched out here.
If you want to ask questions or debate other diabetes-related issues, there's a nice community growing on the Blood Sugar 101 Facebook page, where you are welcome to post your thoughts on topics other than the subject of this post.
Publishing the book version of the site has taught me that most people still find books a better way to study a complex topic, even when the information in the book is also available on a web site.
This has been a pleasant surprise, as has been the steady stream of fan mail that the book generates. There's no question that people who read the book learn far more than people who visit the site, if for no other reason than that most people who visit the site only read a couple pages before leaving.
So that raises the question: Should I write another book? And if I do, what should be its subject?
I have some ideas of my own, but before I plunge in I'd love to hear some feedback from you about what topics you would like to learn more about. I'd also like to know, iIf you read my book, Blood Sugar 101, if you thought there was something important that was left out.
Keep in mind, of course, that there are many topics I'd love to be able to write about that are too poorly researched to justify a book. For example, I have spent quite a lot of time looking into the physiology of weight loss, but the more research I read, the less conviction I have that any of it can be trusted. The quality is just abysmal and unlike the publications about diabetes, my many hours of study did not turn up any overlooked gems.
On the other hand, very little has come up that is new since I wrote Blood Sugar 101. In fact, it is rather depressing just how little that would be of any use to someone trying to preserve their health.
But though I might feel that way, life has taught me that one problem with making yourself into an "expert" in some topic area is that the things that bore me after a decade of daily attention to the topic may be exciting to people who haven't soaked their head in this stuff for years.
So I welcome your feedback. What kind of book--if any--do you think would be most useful to a reader who has already read Blood Sugar 101? Click on the comment link below and share your thoughts with me. The only thing I will ask is that you keep your comments on the topic I've sketched out here.
If you want to ask questions or debate other diabetes-related issues, there's a nice community growing on the Blood Sugar 101 Facebook page, where you are welcome to post your thoughts on topics other than the subject of this post.
October 5, 2011
Normal Blood Sugars in Pregnancy
I have until now avoided discussing the issue of what normal blood sugars should be in pregnancy because it looked like gynecologists were being more aggressive with blood sugar control during pregnancy then other doctors.
Blood sugar control is particularly important in pregnancy because a fetus that is exposed to continually high blood sugars will experience significant changes in the way that its genes express which will affect its blood sugar metabolism for the rest of its life.
High blood sugar will also make babies very large, which poses problems when it is time for delivery, some life-threatening.
Blood sugars are lower in pregnant women because there is a higher blood volume during pregnancy, but it is starting to look like the targets gynecologists have been recommending, which would have been excellent for non-diabetic women are considerably higher than normal.
This was made clear by a new meta-study that analyzed a series of studies of the blood sugars of a wide range of normal pregnant women using Continuous Glucose Monitoring, home testing, and hospital lab results. It makes it clear that the current targets for pregnancy are probably too high.
Here is the full text version of the meta-study:
Patterns of Glycemia in Normal Pregnancy: Should the current therapeutic targets be challenged? Teri L. Hernandez, et al. Diabetes Care July 2011 vol. 34 no. 7 1660-1668.
It concludes that the following appear to be truly normal blood sugars for pregnant women:
AVERAGE BLOOD SUGARS IN NORMAL PREGNANT WOMEN
Fasting: 70.9 ± 7.8 mg/dl (3.94 mmol/L ± .43)
One Hour Post Meal: 108.9 ± 12.9 mg/dl (6.05 ± .72 mmol/L)
Two Hours Post Meal: 99.3 ±10.2 mg/dl (5.52 ± .57 mmol/L )
A commentary published in this month's Diabetes Care gives more insight into the importance of this study and why doctors should aggressively lower blood sugars in pregnancy. You can read it HERE. The Full text version is free.
The commentary suggests that pregnant women should strive for blood sugars that don't exceed the first standard deviation of normal (that's the average with the number following the "±" added to it. Doing that gives us targets that should not exceed
RECOMMENDED MAXIMUM BLOOD SUGARS FOR PREGNANT WOMEN WITH DIABETES
Fasting: 79 mg/dl (4.4 mmol/L)
One Hour After Meals: 122 mg/dl (6.8 mmol/L)
Two Hours After Meals: 110 m/gdl (6.1 mmol/L)
The challenge during pregnancy, of course, is to lower blood sugar without going too low because hypos can also cause problems for the fetus. In addition, the solution that works so well for non-pregnant people--cutting way back on carbs--raises issues.
Very low carb diets raise the concentration of ketones in the blood. This isn't a problem when we aren't pregnant--most of our organs can run quite happily burning ketones. But because ketones are usually produced when humans are starving, it is very possible that fetuses produced when the mother is in a ketogenic state may end up with environmentally-produced permanent changes to their genes (epigenetic changes, to use a technical term) that will predispose them to gaining weight once they are born, because ketones may signal the forming baby that they are being born into an environment of scarcity.
The fact that ketogenic diets downregulate T3 and slow the thyroid in non-pregnant people raises the question about whether a ketogenic diet might also have a negative effect on the baby's developing thyroid.
So it's generally considered to be best for pregnant women to lower their blood sugar as much as possible by cutting back on carbohydrates but to keep their carbs over the threshold (anywhere from 60-100 grams a day) where glycogen is depleted and the concentration of ketones in the blood and urine rises.
You can usually detect your own ketogenic threshold easily: it is the carbohydrate intake level at which, after eating at that level for three days, you suddenly lose anywhere from 3 to 8 lbs (depending on your size.) Raising carbs will immediately restore those quickly lost pounds because they are not fat (or growing baby) but the glycogen stored in your liver and muscles which gets burned away when your carbohydrate level is too low to replenish it.
If you eat only enough carbohydrates to keep your glycogen replenished, you won't have to worry that ketones will give your fetus the message that it's being born into an environment where starvation is occurring and shift its genes into a state where they optimize fat storage.
If you can't lower your blood sugar during pregnancy with diet alone, insulin is a safe medication for pregnant women and most doctors provide pregnant women with diabetes much better education in how to use insulin than family doctors do to their non-pregnant peers.
If you are reading this because you are pregnant and have just discovered you have gestational diabetes though you were not diabetic before your pregnancy, here's one last important fact to keep in mind: abnormal blood sugars in pregnancy almost always point to the pre-existence of abnormal sugars in the non-pregnant state that were missed by your doctor because the tests doctors use to screen for diabetes do a woefully bad job of diagnosing it until you have suffered years of high blood sugars that may irreversibly damage your organs.
Once you deliver your baby, don't rely on doctors to tell you if your blood sugar is normal. Test your blood sugar after meals every so often with a meter to make sure that you are not going over the 140 mg/dl (7.7 mmol/L) level at one hour that is truly normal in the non-pregnant state and that you are under 120 mg/dl (ideally far under) at two hours. If you are going over these levels, cut back on your carbohydrates and if that doesn't help, find a doctor willing to work with you to use safe drugs like metformin that can keep your sugars in the normal range for life.
Don't rely on the A1c test, as most doctors now do. It has been shown to be a poor guide to the high post-meal sugars that characterize the very early stages of Type 2 diabetes and which cause heart disease and early diabetic complications.
Blood sugar control is particularly important in pregnancy because a fetus that is exposed to continually high blood sugars will experience significant changes in the way that its genes express which will affect its blood sugar metabolism for the rest of its life.
High blood sugar will also make babies very large, which poses problems when it is time for delivery, some life-threatening.
Blood sugars are lower in pregnant women because there is a higher blood volume during pregnancy, but it is starting to look like the targets gynecologists have been recommending, which would have been excellent for non-diabetic women are considerably higher than normal.
This was made clear by a new meta-study that analyzed a series of studies of the blood sugars of a wide range of normal pregnant women using Continuous Glucose Monitoring, home testing, and hospital lab results. It makes it clear that the current targets for pregnancy are probably too high.
Here is the full text version of the meta-study:
Patterns of Glycemia in Normal Pregnancy: Should the current therapeutic targets be challenged? Teri L. Hernandez, et al. Diabetes Care July 2011 vol. 34 no. 7 1660-1668.
It concludes that the following appear to be truly normal blood sugars for pregnant women:
AVERAGE BLOOD SUGARS IN NORMAL PREGNANT WOMEN
Fasting: 70.9 ± 7.8 mg/dl (3.94 mmol/L ± .43)
One Hour Post Meal: 108.9 ± 12.9 mg/dl (6.05 ± .72 mmol/L)
Two Hours Post Meal: 99.3 ±10.2 mg/dl (5.52 ± .57 mmol/L )
A commentary published in this month's Diabetes Care gives more insight into the importance of this study and why doctors should aggressively lower blood sugars in pregnancy. You can read it HERE. The Full text version is free.
The commentary suggests that pregnant women should strive for blood sugars that don't exceed the first standard deviation of normal (that's the average with the number following the "±" added to it. Doing that gives us targets that should not exceed
RECOMMENDED MAXIMUM BLOOD SUGARS FOR PREGNANT WOMEN WITH DIABETES
Fasting: 79 mg/dl (4.4 mmol/L)
One Hour After Meals: 122 mg/dl (6.8 mmol/L)
Two Hours After Meals: 110 m/gdl (6.1 mmol/L)
The challenge during pregnancy, of course, is to lower blood sugar without going too low because hypos can also cause problems for the fetus. In addition, the solution that works so well for non-pregnant people--cutting way back on carbs--raises issues.
Very low carb diets raise the concentration of ketones in the blood. This isn't a problem when we aren't pregnant--most of our organs can run quite happily burning ketones. But because ketones are usually produced when humans are starving, it is very possible that fetuses produced when the mother is in a ketogenic state may end up with environmentally-produced permanent changes to their genes (epigenetic changes, to use a technical term) that will predispose them to gaining weight once they are born, because ketones may signal the forming baby that they are being born into an environment of scarcity.
The fact that ketogenic diets downregulate T3 and slow the thyroid in non-pregnant people raises the question about whether a ketogenic diet might also have a negative effect on the baby's developing thyroid.
So it's generally considered to be best for pregnant women to lower their blood sugar as much as possible by cutting back on carbohydrates but to keep their carbs over the threshold (anywhere from 60-100 grams a day) where glycogen is depleted and the concentration of ketones in the blood and urine rises.
You can usually detect your own ketogenic threshold easily: it is the carbohydrate intake level at which, after eating at that level for three days, you suddenly lose anywhere from 3 to 8 lbs (depending on your size.) Raising carbs will immediately restore those quickly lost pounds because they are not fat (or growing baby) but the glycogen stored in your liver and muscles which gets burned away when your carbohydrate level is too low to replenish it.
If you eat only enough carbohydrates to keep your glycogen replenished, you won't have to worry that ketones will give your fetus the message that it's being born into an environment where starvation is occurring and shift its genes into a state where they optimize fat storage.
If you can't lower your blood sugar during pregnancy with diet alone, insulin is a safe medication for pregnant women and most doctors provide pregnant women with diabetes much better education in how to use insulin than family doctors do to their non-pregnant peers.
If you are reading this because you are pregnant and have just discovered you have gestational diabetes though you were not diabetic before your pregnancy, here's one last important fact to keep in mind: abnormal blood sugars in pregnancy almost always point to the pre-existence of abnormal sugars in the non-pregnant state that were missed by your doctor because the tests doctors use to screen for diabetes do a woefully bad job of diagnosing it until you have suffered years of high blood sugars that may irreversibly damage your organs.
Once you deliver your baby, don't rely on doctors to tell you if your blood sugar is normal. Test your blood sugar after meals every so often with a meter to make sure that you are not going over the 140 mg/dl (7.7 mmol/L) level at one hour that is truly normal in the non-pregnant state and that you are under 120 mg/dl (ideally far under) at two hours. If you are going over these levels, cut back on your carbohydrates and if that doesn't help, find a doctor willing to work with you to use safe drugs like metformin that can keep your sugars in the normal range for life.
Don't rely on the A1c test, as most doctors now do. It has been shown to be a poor guide to the high post-meal sugars that characterize the very early stages of Type 2 diabetes and which cause heart disease and early diabetic complications.
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