Dr K K Aggarwal

All about A1C (Part 1)

1. A1c is a blood test that provides information about a person’s average levels of blood glucose over the past 3 months. It is also called the hemoglobin A1c, HbA1c or glycohemoglobin test.

2. The A1c test is based on the attachment of glucose to hemoglobin, the protein in red blood cells (RBCs) that carries oxygen. In the body, RBCs are constantly forming and dying, but typically they live for about 3 months. Thus, the A1c test reflects the average of a person’s blood glucose levels over the past 3 months. The result is reported as a percentage. The higher the percentage, the higher a person’s blood glucose levels have been. A normal A1c level is below 5.7%.

3. In 2009, an international expert committee recommended the A1c test as one of the tests available to help diagnose type 2 diabetes and pre-diabetes. Previously, only the traditional blood glucose tests were used to diagnose diabetes and pre-diabetes.

4. Because the A1c test does not require fasting and blood can be drawn for the test at any time of day, experts are hoping its convenience will allow more people to get tested thus, decreasing the number of people with undiagnosed diabetes.

5. AIc testing is important because early in the disease diabetes has no symptoms. Testing enables health care providers to find and treat diabetes before complications occur and to find and treat pre-diabetes, which can delay or prevent type 2 diabetes from developing.

6. No test is perfect, the A1c and blood glucose tests are the best tools available to diagnose diabetes, a serious and life-long disease.

7. A1c laboratory tests are now standardized. Earlier, the A1c test was not recommended for diagnosis of type 2 diabetes and pre-diabetes because the many different types of A1c tests could give varied results. The accuracy has been improved by the National Glycohemoglobin Standardization Program (NGSP), which developed standards for the A1c tests. The NGSP certifies that manufacturers of A1c tests provide tests that are consistent with those used in a major diabetes study. The study established current A1c goals for blood glucose control that can reduce the occurrence of diabetes complications, such as blindness and blood vessel disease. (Nathan DM, Genuth S, Lachin J, et al. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. New England Journal of Medicine 1993:329(14)977–86).

8. When the A1c test is used for diagnosis, the blood sample must be sent to a laboratory that uses an NGSP-certified method for analysis to ensure the results are standardized. Blood samples analyzed in a health care provider’s office, known as point-of-care (POC) tests, are not standardized for diagnosing diabetes. The following table provides the percentages that indicate diagnoses of normal, diabetes, and pre-diabetes according to A1c levels.

Diagnosis* A1c Level
Normal < 5.7%
Diabetes ≥ 6.5%
Pre-diabetes 5.7 – 6.4%
*Any test for diagnosis of diabetes requires confirmation with a second measurement unless there are clear symptoms of diabetes.

9. Having pre-diabetes is a risk factor for getting type 2 diabetes. People with pre-diabetes may be retested each year. Within the pre-diabetes A1c range of 5.7-6.4%, the higher the A1c, the greater the risk of diabetes. Those with pre-diabetes are likely to develop type 2 diabetes within 10 years, but they can take steps to prevent or delay diabetes.

10. A1c test may be used at the first visit to the health care provider during pregnancy to see if women with risk factors had undiagnosed diabetes before becoming pregnant. After that, the oral glucose tolerance test (OGTT) is used to test for diabetes that develops during pregnancy—known as gestational diabetes. After delivery, women who had gestational diabetes should be tested for persistent diabetes. Blood glucose tests, rather than the A1c test, should be used for testing within 12 weeks of delivery.

11. The standard blood glucose tests used for diagnosing type 2 diabetes and pre-diabetes, the fasting plasma glucose (FPG) test and the OGTT, are still recommended. The random plasma glucose test, also called the casual glucose test, may be used for diagnosing diabetes when symptoms of diabetes are present. In some cases, the A1c test is used to help health care providers confirm the results of a blood glucose test.

12. In some people, a blood glucose test may indicate a diagnosis of diabetes while an A1c test does not. The reverse can also occur i.e. an A1c test may indicate a diagnosis of diabetes even though a blood glucose test does not. Because of these variations in test results, health care providers repeat tests before making a diagnosis. People with differing test results may be in an early stage of the disease, where blood glucose levels have not risen high enough to show on every test. Sometimes, making simple changes in lifestyle—losing a small amount of weight and increasing physical activity—can help people in this early stage reverse diabetes or delay its onset.
13. All laboratory test results can vary from day to day and from test to test. Results can vary.
a. Within the person being tested: A person’s blood glucose levels normally move up and down depending on meals, exercise, sickness, and stress.
b. Between different tests: Each test measures blood glucose levels in a different way. For example, the FPG test measures glucose that is floating free in the blood after fasting and only shows the blood glucose level at the time of the test. Repeated blood glucose tests, such as self-monitoring several times a day with a home meter, can record the natural variations of blood glucose levels during the day. The A1c test represents the amount of glucose attached to hemoglobin, so it reflects an average of all the blood glucose levels a person may experience over 3 months. The A1c test will not show day-to-day changes.

The following chart shows how multiple blood glucose measurements over 4 days compare with an A1c measurement.

Note: Blood glucose (mg/dL) measurements were taken four times per day (fasting or pre-breakfast, pre-lunch, pre-dinner, and bedtime). The straight black line indicates an A1c measurement of 7.0%. The blue line shows blood glucose test results from self-monitoring four times a day over a 4-day period.

c. Within the same test: Even when the same blood sample is repeatedly measured in the same laboratory, the results may vary due to small changes in temperature, equipment, or sample handling.

14. The A1c test result can be up to 0.5% higher or lower than the actual percentage. This means an A1c measured as 7.0% could indicate a true A1c anywhere in the range from 6.5-7.5%. The drawing below shows the range of variation that can occur when an A1C is 7.0% on the lab report.

Eggs, more than one per week, raises the risk of diabetes

The advertisement in Indian TV “Sunday ho ya Monday, Roj Khao Ande” needs a revision as it is not based on scientific facts.

A new study has shown that people who eat eggs every day may substantially increase their risk of type 2 diabetes. India is already the diabetic capital of the world and continuing promotion of eating eggs every day will add to the burden.

In the study, men with the highest level of egg consumption, seven or more per week, were 58% more likely to develop type 2 diabetes than those who did not eat eggs, and women were 77% more likely to become diabetic if they ate at least an egg a day. The study done by Dr Luc Djoussé of Brigham and Women’s Hospital and Harvard is published in the Journal Diabetes Care.

Other salient features of the study were:

• Levels of egg intake above one a week incrementally increased diabetes risk in both men and women.
• Eggs are a major source of dietary cholesterol (about 200 mg per egg).
• Eggs add about 1.5 g of saturated fat each to the diet
• Eggs may influence glucose metabolism primarily through their effect on cholesterol.
• Each egg also contributes about 0.7 g of polyunsaturated fat, which neutralize the risk to some extent only.
• The average one-egg-a-week consumption was not associated with increased diabetes risk.
• The study included 20,703 male doctors without baseline diabetes from the Physicians’ Health Study I (1982-2007) and 36,295 similarly diabetes-free female health professionals from the Women’s Health Study (1992-2007). Over a mean follow-up of 20.0 years in men and 11.7 years in women, 1,921 men and 2,112 women developed type 2 diabetes. Diabetes was more common in men and women who reported eating more than the average one egg a week.

Snoring how boring

When this irritating sound blasts through the quietness of the night it can drive the sanest of people insane – well almost! There are many couples who have divorced on this ground. It’s no joke to be accused to snoring – neither for the snorers nor for the sufferers who have to endure sleepless nights! Even the fair sex is not immune to this malady howsoever they might deny it.

The cause of snoring is air flowing through the open mouth and causing the soft palate (side area around the back of the tongue and the tonsils) to vibrate. This results in the production of sound – the snore!

Medically, snorers are found to be more prone to :

• Heart attacks
• Sudden death
• Arrhythmias – according to MEDINEWS a leading medical journal.

Certain conditions can predispose to snoring. These are :

• Enlarged tonsils or adenoids
• Congestion in the nasal sinuses
• A deviated nasal septum
• Loose dentures
• Nasal polyps
• Sleeping on your back (causes the tongue to fall back and block the windpipe partially)
• Aging causes the throat muscles to become flabby. This is also caused by alcohol, and certain drugs – tranquilizers, pain killers, or sedatives, all of which depress the brain and cause the muscles to be loose.

Practical remedies for this malady

• Find the cause and treat it if snoring is due to any of the above conditions. Corrective measures should be undertaken ant it may stop snoring.
• Sleeping on the side: The tongue does not block, the airway and hence helps to prevent snoring for this purpose a ball is stitched on the back of the night suit shirt to remind the person to sleep on the side.
• A special anti snoring pillow can be made in which the portion under the neck is higher than the one under the head, hence extending the neck this prevents snoring.
• Lose weight if you are overweight, especially around the belly.
• Stop smoking as smoke irritates the nasal mucosa and the throat.
• Sleep without dentures if you use them.
• For the sufferers one last line: Stuffing your ears with cotton wool (or your partners mouth) or sleeping in another room may be the best answer to the solution. If nothing helps – just pray to God for endurance.