Definitions & Test Interpretation

A1C (hemoglobin A1C, glycosylated hemoglobin, Hgb A1C, HbA1C) - Hemoglobin is the substance in red blood cells that carries oxygen to the cells. Glucose (the main sugar your body uses for fuel) attaches to red blood cells. The A1C test measures the amount of glucose that has become attached to your red blood cells throughout their (3 to 4 month) lifetime.  A1C goes by a number of other names including hemoglobin A1C, glycosylated hemoglobin, HgbA1C and HbA1C. It is important to note that A1C levels are measured in different units and on a different scale than is blood glucose (though thay may change in the future); hence an A1C level of seven is NOT the same as saying that your average blood glucose is seven. More information.

How important is it to monitor and optimize your A1C level? Well, how about this; the UKPDS study showed that - and this is astounding - a one percent drop in A1C (which is about a 2 mmol/L drop in your average blood sugar level) reduces the likelihood of your developing microvascular complications (that is; eye, kidney and nerve) damage by THIRTY SEVEN PERCENT. That's incredible, isn't it? Don't know your own A1C? Better find out, eh? It is important to bear in mind that A1C levels do not tell the whole story about your blood glucose control. For example you could have lots of lows and lots of highs and have an excellent "average" blood glucose (and hence an excellent A1C)..sort of like the old expression that if you put one foot in ice water and one foot in boiling water on average you feel fine! A study published in 2008 in the journal Diabetes Care indicated the following correlation between average (mean, to be more precise) blood glucose and A1C (note that at most labs a normal A1C is under about 6 percent):

A1C (in percent)	Average blood sugar (in mmol/l)
5	5.4
6	7.0
7	8.6
8	10.2
9	11.8
10	13.4
11	14.9
12	16.5

"Brittle" diabetes - Brittle diabetes is defined as diabetes with wide swings in blood glucose levels for no reason and leading to recurring hospital visits with either hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar). I almost never see this. Much more commonly erratic blood glucose levesl are due to something that we can indeed put our finger on. Like bowel problems such as celiac disease (which interferes with the absorption of nutrients from the gut) or diabetic gastroparesis (in which the stomach does not expel food properly into the small bowel which in turn leads to erratic absorption of food). Or problems with insulin administration such as injecting insulin into areas where there is either scar tissue or fat build-up (lipohypertrophy). Or, on occasion, because of other health problems such as anorexia nervosa or even intentionally not taking one's insulin. Before you get labelled as having "brittle diabetes" it is crucial that a search be made for these other, correctable causes of poor sugar control.

C-peptide Level - This is a protein that is created simultaneously with the production of insulin by the pancreas. If C-peptide is present it suggests that the pancreas still has the ability to produce insulin (though not necessarily enough insulin to avoid extra injections). More information.

Diabetes - Technical definition: "a metabolic disorder characterized by the presence of high blood glucose due to a problem with insulin production or insulin action." My preferred definition (don't quote me on this...I made up the following): "a condition of high risk for cardiovascular disease occurring in the setting of high blood glucose." Why would I make up my own definition? A burst of creativity perhaps? Well, only in part. No; the reason I would take it upon myself to make up my own definition of diabetes is because I feel that we must get away from the notion that diabetes is "just a sugar problem." Diabetes is not just a sugar problem. Diabetes is a whole body problem. And people with diabetes get sick and die primarily from disease of the blood vessels. Indeed, up to EIGHTY PERCENT of people with diabetes die of so-called "macrovascular disease." Strokes. Heart attacks. Things like that. But I say these things not to depress you. On the contrary, I say them to EMPOWER you because these problems are NOT inevitable. Indeed, they are often preventable. Have a look at my Ten Golden Rules for Preventing Complications to find out how.

 Diabetes Specialist - Technical definition: "a physician who specializes in the care of individuals with diabetes." My preferred definition (don't look for a footnote; I made up this definition too): "a guidance counsellor for people with diabetes."^(c) A diabetes specialist should not be (and should not be considered to be) a principal or a judge, a disciplinarian or a police officer. A diabetes specialist is there to serve as a guide; steering people with diabetes in the right direction, helping set goals and designing strategies to achieve them. You should never have to fear showing your log book to your diabetes specialist. Your log book is not a report card; it is a tool to assist with your diabetes management. A diabetes specialist is but one member of the health care team; a team with the shared goal of helping you along your journey with diabetes. Oh, and incidentally, the ultra-fancy term for a diabetes specialist is a "diabetologist."

Glycemic Index - I talk about this here.

The Health Care Team - If you have diabetes then I hope you never feel that you are "on your own." Group effort is what is needed. The way I see it, the key members of "the team" are you and your family (if one member of the family has diabetes, then everyone has to deal with it), your family physician, your diabetes educators (a dietitian and a nurse who specialize in diabetes) and what I'll call the "core support staff" (consisting of a diabetes specialist and an eye specialist) and the "other support staff" (consisting of those individuals who are not usually required, but are excellent resources to be used on an "as needed" basis) consisting of a cardiologist (heart specialist), a nephrologist (kidney specialist), a neurologist, podiatrist or chiropodist, etc. Pharmacists, of course, also have an invaluable role to play. I hope you noticed that I put the person with diabetes first on the team. I thought it was of significant interest that at the annual meeting of the American Diabetes Association in June, 2002, the then president of the ADA (Dr. Christopher Saudek) said "diabetes education is the single greatest advance ever made in diabetes care." The take home message; If you haven't seen a diabetes educator then you are missing out on a key component of your treatment!

Insulin Resistance - Insulin is a hormone produced in the pancreas. Insulin is necessary to allow for glucose ("sugar") to enter into the body's cells (particularly the muscle and fat cells) from the blood stream. In type 2 diabetes, insulin levels are often quite decent, but the insulin simply does not work well. The body is resistant to the action of the insulin. And if the glucose cannot get into the tissues then it hangs around in the blood so that blood glucose levels become elevated. Insulin resistance can be improved upon by a variety of measures, most important of which is following appropriate lifestyle measures. More information. Both of these links also discuss Syndrome X.

Lipids - There is "good" cholesterol (HDL: High Density Lipoprotein) and there is "bad" cholesterol (LDL: Low Density Lipoprotein). (To remember which is which, just think of "L" for LOUSY to remember LDL is the bad one and should be LOW and think of "H" for HEALTHY to remember HDL is the good one and should be HIGH). Because diabetes is such a significant risk factor for heart disease, it is crucial that your levels not just be "good" or "okay;" they need to be GREAT! And for most people with diabetes that means an LDL of under 2.0. The HDL (which you want to be high) should preferably be above 1.15 (for men) or 1.40 (for women). Triglycerides are the "fats" in the blood and should measure less than 1.7. The one other number you would be well off to know is called the cholesterol/HDL ratio; this should be under 4.0. You can see that we are dealing with a mixed bag here-one cholesterol we want to be high, one we want to be low and then we throw in this triglyceride stuff too. HDL, LDL and triglycerides are all part of a group of substances in the blood that are collectively referred to as "lipids." And when the lipids are abnormal, we call that "dyslipidemia" - which basically means "a bunch of different lipid problems" rather than the older term "hyperlipidemia" (which just meant "high cholesterol"). More information.

Although we have become increasingly aggressive in terms of when to intervene with medication to reduce high LDL readings, the Heart Protection Study makes a very strong case for treating virtually all people with diabetes with cholesterol-lowering therapy (with drugs called "statins") regardless of what your cholesterol level is to start with.

Lipohypertrophy - Lipohypertrophy is the accumulation of excess quantities of fatty tissue in areas where insulin has been injected too many times. It is illustrated in the picture below:

You may at first glance think that the bulges are knees, but they are actually areas of fat over the thighs. The knees are at the bottom of the picture. This is an extreme example of lipohypertrophy chosen for the sake of illustration. Nevertheless, even milder areas of lipohypertrophy are important to note for two reasons. First, they can be a problem cosmetically. Second, insulin injected into areas of lipohypertrophy can be erratically absorbed leading, in turn, to erratic blood sugars. The key to preventing lipohypertrophy is to rotate your injection sites. DON'T KEEP INJECTING YOUR INSULIN INTO THE SAME AREA. (I figured if I capitalized the previous statement you'd see that I really, really, really mean it.). If areas of lipohypertrophy are spared further insulin injections they may (very slowly; it can take years) improve.

Microalbumin - Microalbumin is a small quantity of protein detected in the urine. It is present in tiny quantities in healthy people, but increases in amount if the kidneys are becoming damaged. Basically, it is an "early warning system." Although the best way to determine if there is a kidney problem is to measure the level of microalbumin in a 24 hour collection of urine (a normal level of microalbumin in a 24-hour collection of urine is no more than 30mg), a perfectly good and simpler screening test is to measure the microalbumin level in a single urine sample (note that this must be specifically ordered as a urine "microalbumin/creatinine" ratio in order to be of maximal value).

Pneumovax - This is a vaccine to prevent a type of bacterial pneumonia caused by a germ called pneumococcus. It is not the same as a "flu shot" which is designed to prevent a type of viral pneumonia caused by influenza. The American Diabetes Association recommendation is that Pneumovax be given only once [except(and, if this sounds confusing, I agree) "a one-time revaccination is recommended if you are older than sixty-four and you had your previous Pneumovax shot when you were less than sixty-five if the vaccine was administered more than five years ago." GEESH!].