Normal Blood Sugar Levels and Diabetes

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February 25, 2010
Avandia, a well-known drug used in the treatment of type-2 diabetes in the battle to control blood sugar levels, is again the subject of controversy after the release this week of a report on an investigation carried out over the last two years by the U.S. Senate Finance Committee.

Among other criticisms, the report claimed that the drug manufacturer had not kept the public informed of risks that the company knew to be associated with the drug.

The chairman of the investigation committee, Senator Max Baucus, said “Americans have a right to know there are serious risks associated with Avandia and GlaxoSmithKline, the manufacture, had a responsibility to tell them.”

The committee is also critical of the Federal Drug Agency (FDA) for allowing continued marketing of the drug in spite of warnings of the risks. Some of the FDA’s own health safety experts have raised alarms about its safety, saying it should not be on the market.

GlaxoSmithKline, the manufacturer, vigorously disagrees with the conclusions stated in the report regarding the risks and dangers to health and continues to defend the efficacy and safety of the drug as it has done on several occasions since the approval of Avandia by the FDA in 1999.

Cardiovascular deaths and severe adverse events
Safety issues about the drug were raised soon after its approval. In March of 2000, for instance, Dr. John Buse, Chief of Endocrinology at the University of North Carolina wrote to the FDA expressing concerns and warning of the risks to those using Avandia, saying there is a “worrisome trend in increased cardiovascular deaths and severe adverse events” occurring among those using the drug. Dr. Buse was also critical of the marketing of Avandia and the actions taken to understate the risks associated with the drug.

FDA Alert issued May, 2007
Warnings from other sources continued to be voiced and in 2007 much publicity was given to the FDA’s official Alert issued to healthcare professionals.

The New England Journal of Medicine, early in 2007, had published results of a meta-analysis by cardiologist Steve Nissan of the Cleveland Clinic showing a 43 percent increase in heart attacks in patients using Avandia. Although the conclusions of the study were contested by the manufacturer, the FDA issued an official Alert, noting that the analysis had shown a “significant increase in the risk of heart attack and heart related deaths in patients taking Avandia.” In their view however, other data provided contradictory evidence and it was stated that the “FDA’s review of available data is ongoing.”

The FDA Alert also said that it was providing the emerging information to the doctors so that they and their patients could make individualized decisions on its use. My own decision as a patient after discussing with my doctor was to immediately stop taking Avandia.

Now, many years later, we appear to be in the same place, criticism continues and GlaxoSmithKline rejects any claims that the drug is unsafe. Company spokeswoman Nancy Pekarek, appearing on CNN a few days ago said “We disagree with the conclusions in the report. The FDA has reviewed the data and concluded that the drug should be on the market.”

Meanwhile, there are hundreds of thousands of our fellow diabetics who still take the drug. And the complications of diabetes continue to take their toll, for whatever reason whether hastened by a drug or otherwise, there are more people dying of diabetes complications than are being killed in Afghanistan, we need help and prompt decisions,

The FDA commissioner is reviewing the report issued by the Senate Investigation Committee, while awaiting recommendations of the agency’s own group of advisors. I assume those would include the beliefs of some of the FDA’s health safety experts who say the drug should be withdrawn. The advisory committee’s report is expected in July and at the present time the opinion of the FDA is that patients should not stop taking Avandia.

In our struggle to achieve normal blood sugar levels, perhaps Avandia really is effective and beneficial, in spite of the apparent risks. Let us hope that after ten years of controversy, a final decision is near on whether Avandia is safe or not.

Link for 342 page  Senate Finance Committee report.

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For type-1 diabetics, can this pump improvement make it reality?

The development of what is being called an “artificial pancreas”, was reported in the pages of the February 2010 issue of Great Britain’s leading medical journal, The Lancet, bringing new hope to type-1 diabetics who depend on insulin injections every day to manage their disease.

Reference: “Closed-loop insulin delivery in children and adolescents with type 1 diabetes”. Roman Hovorka et al. The Lancet, February 5, 2010

With the aid of 17 type-1 diabetic children and teenagers, spending 54 over-nights in hospital during which they experienced varying conditions to simulate real life situations, researchers at England’s Cambridge University have successfully tested a device described in The Lancet as “a milestone in the quest for the holy grail of artificial insulin delivery that started almost 50 years ago”. The results were compared with those of their regular subcutaneous infusion pumps.

With the aid of 17 young type-1 diabetics confined to a hospital setting but in varying conditions to simulate real life situations, researchers at England’s Cambridge University have successfully tested a device described in The Lancet as “a milestone in the quest for the holy grail of artificial insulin delivery that started almost 50 years ago”.

The importance of this development cannot be over-estimated although, apparently, it will still take some years to perfect and for it to pass through the necessary series of trials yet to be carried out.

If it can be brought into production it would fulfill the promise of a close to normal life with normal blood sugar levels for all insulin-dependent diabetics who choose to use it, most of whom are of the Type-1 form, also called juvenile diabetes.

Insulin and Type-1 diabetes
Insulin is needed to help the absorption of glucose into the cells of the body where it provides the energy required in the metabolic processes to sustain life.

Type-1 diabetes, a very serious disease usually diagnosed in childhood, is a disorder of the body’s immune system in which an organ called the pancreas becomes impaired and ceases to produce the hormone insulin. The result is that it becomes essential to administer artificial insulin by daily injections with a special insulin primed needle or by an insulin pump usually attached to the body. This also first involves a series of finger-pricks to obtain a blood droplet for testing to determine the amount of insulin actually required, if any.

To the non-diabetic person I would say:
If you could just imagine that you are a type-1 diabetic. The blood tests and the injection of insulin has to be done multiple times every day of your life in order to stay alive. You would then realize how wonderful the “artificial pancreas” would be for you. There are also many other diabetics, suffering from a different form of diabetes called Type-2, many of whom also have to inject insulin.

Depending on the types and amounts of food being consumed, blood sugar levels vary throughout the day and insulin is needed to maintain them within a safe range. Electronic subcutaneous insulin pumps have been in use for many years, able to deliver insulin at a slow and steady fixed rate throughout the day, adjustable as required by the diabetic after taking finger-prick test readings.

Providing a more accurate response to changing blood sugar levels
But the development of the new insulin pump device provides a better and more accurate response to changing glucose levels as they occur, signaled by a glucose sensor that monitors the fluctuating blood sugar levels, enabling the delivery of insulin doses that are matched to the glucose level detected.

The test results showed that the system maintained blood glucose levels within the normal range for 60 percent of the time compared to the usual 40 percent provided by the regular insulin pumps. Also the new device is able to prevent glucose falling to dangerously low levels while keeping overall blood glucose levels stable all the time. This is very significant for the reassurance of parents whose fear is that their child may fall into a coma because of a drop from normal blood sugar levels to dangerously low blood sugars at night while sleeping.

In the United States there are also several ongoing projects to develop and perfect an artificial pancreas able to provide a variable insulin delivery system in response to sensors that monitor changing blood glucose levels.

So let us hope that we are on the threshold of a new era for the insulin dependent diabetic. It cannot come too soon.

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The aim of every diabetic

For many of us who are diabetic, to even get close to normal blood sugar levels would be an achievement, a triumph in fact, and for some just a dream.

Once diagnosed as having diabetes, becoming close to normal may be the best we can achieve, although many well known doctors specializing in the treatment of the disease insist it can be done, and even that the condition can be reversed with the right combination of exercise and diet, usually with the low carbohydrate content approach. But that’s a different topic that is worth discussing separately while we confine ourselves here to identifying normal blood sugar levels in the non-diabetic population and then perhaps compare them to our own.

The range of normal levels for blood glucose
In checking many sources, I found that that there is a variation in the values considered by some as normal.  But in the main I can summarize the results, including those published by the American and Canadian Diabetes Associations as follows, and where fasting is usually meant as an overnight 8-hour period without food or liquids other than water.

Fasting blood sugar levels measured after about 8 hours without food or drink other than water should be less than 108 mg/dL (6.0 mmol/L) but no lower than 72 mg/dL (4.0 mmol/L).

Two-hours after a meal blood sugar levels should be 90 to 144 mg/dL (5.0 to 8.0 mmol/L)

Within 3 hours after a meal they should be back to normal levels

Except for a two-hour period after a meal my own healthcare providers informs me that the blood sugar levels should be less than 108 mg/dL (6.0 mmol/L) and they should always be above 72 mg/dl (4.0 mmol/L). If you are a diabetic that will probably not be the case.

According to the American Diabetes Association, for a random test taken during the day they should be less than 140 mg/dL (7.8 mmol/L). That sound high to me, but I found that in an ADA reference on normal blood sugars.

A1c – the 12 week period test
For a test that indicates the levels over a 12 week period, called the A1c, or Glycosylated hemoglobin test, the normal level is less than 6%. What that means is that less than 6% of the hemoglobin fraction in your blood has glucose attached to it. The hemoglobin content of blood, including water, is about 35% and it is hemoglobin that carries oxygen from the lungs to the rest of the body for use by the body’s cells.

For most diabetics: typical target  according to
the Canadian Diabetes association (CDA):

Fasting levels before meals target is 72 to 126 mg/dL (4.0 to 7.0 mmol.L)
Two hours after eating target is 90 to 180 mg/dL (5.0 to 10.0 mmol/L)
A1c level target is 126 mg/dL (7.0 mmol/L)

Note: See at the end, variations of the above according to EASD results described below.

Making the blood test
The usual ways to measure blood glucose levels are either by using a small hand-held meter that measures a drop of blood by pricking the finger tip or, alternatively, through a clinical test, usually made after fasting overnight, in which a technician draws a small amount of blood from a vein into a vial that is then sent to a laboratory for analysis. Results from the two methods do differ to some degree but both provide the information required for the overnight fasting levels and the clinical test additionally provides values that indicate the glucose levels over the prior 12-week period. This test is called the glycosylated hemoglobin test, or A1c for short.

Blood glucose levels can vary in a non-diabetic adult depending on a person’s age. Children of various ages will differ in what is considered normal. Similarly pregnant women often have a higher level of glucose in their blood during pregnancy, but their target should be to stay as close to normal levels as possible to avoid the gestational form of diabetes.

Units of measure
The United States uses different units of measurement than does most of the rest of the world, Canada and the UK included, but converting to either system is simple. The U.S. uses milligrams per deciliter, shown as mg/dL. Dividing the U.S. values by 18 gives the value expressed in the other system of measurement, which is millimols per liter, written as mmol/L.

According to the American Diabetes Association
After checking with national diabetes association sources of major countries, I found it somewhat difficult to pin down an exact figure to establish normal blood sugar levels and that is understandable. The American Diabetes Association’s information site states that the blood sugar levels change throughout the day and night and will vary depending on your food intake, what you’ve eaten, how much, and when, and whether you have exercised in the recent period of time.

The ADA (American Diabetes Association) gives a fasting level of less than 110 mg/dl (6.1 mmol/L) as being normal and from blood tests taken at random times throughout the day they state a normal blood glucose range is in the low to mid 100’s. I assume that to mean from 110 to 150 mg/dL (6.1 to 8.3 mmol/L)

But Results of European Study announced in 2006 differ from the ADA
I discovered a very good report dating from September of 2006 of a lecture given at the annual meeting of the EASD (European Association for Studies in Diabetes) in Copenhagen that offered much detailed research on the subject of normal blood sugars. Reference was made to a study in which glucose was monitored in a group of adults and the results were summarized in a lecture by Professor J.S. Christiansen, illustrated with slides. There was also a substantial amount of other information of interest to diabetics covered at the meeting.

One of the slides showed graphically how the range of normal blood sugar levels peaked between about 7:30 and 8:30 am for a group of 24 young and healthy and not overweight adults. That one hour period was the time when the participants were served breakfast. For the rest of the day, between 6 am and midnight the levels averaged out within a few points either above or below 80 to 85 mg/dl (4.4 to 4.7 mmol/L) with no peaks that could reveal when other meals had been eaten. That seems low and a long way from my own but these participants were in their prime in their early 20’s, that’s not me.

From the foregoing it seems there is a difference of opinion among authoritative voices regarding the adult non-diabetic normal blood glucose levels and my own thoughts are influenced by the results mentioned above from the EASD meeting.

Doing so leads me to conclude that normal blood sugars for most non-diabetic people are:

Under 100mg/dl (5.6.mmol/L) with a peak of 120 mg/dl (6.7 mmo/L) after a proper breakfast and a return to normal within 2 hours after any meal if there has been a spike.

Caution and just for the record
Please Note: I am not a doctor or health care professional and my conclusions are arrived at from an intelligent perusal of available published material of which there is an abundance in existence, some of it conflicting. After considering as many reports as possible I usually prefer to depend on the values quoted by the major diabetes associations, the ADA in the USA, the CDA in Canada, and the NIH in the UK. Those, together with the EASD’s opinions and research results, give me the most confidence in publishing the information here on my own blogsite.

But I must add that there are a few other sources that seem to make scientific sense and that I can believe in and they do not necessarily totally agree at all times with some of the associations I have mentioned above.

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