Gettysburg Medical News
The Clinical View
by P.E. Hoffsten, MD
9 April 2008

IS TIGHT DIABETIC CONTROL GOOD?

            It wasn’t until 1969, that the term diabetes mellitus  was clearly delineated into two different diseases.  There was found to be a Type 1 diabetes that tends to occur in children although in some adults also.  Type 1 diabetes is the result of destruction of the insulin secreting capacity of the person and they cease to make insulin to lower their blood sugar.  This type of diabetes always needs insulin to treat it.  Type 2 diabetes was found to have actually more insulin than normal but it just did not work because the person wasn’t sensitive to it.  This type of diabetes makes up 90% of the diabetic population.  It is the one that is treated with “life style” change and pills; injected insulin is infrequently used.

Surprisingly it wasn’t until the 1990’s that it was clearly shown that good control of  the blood sugar of a diabetic patient prevented the complications of diabetes such as blindness, neuropathy, heart attacks, strokes, and amputations. It was at this time that a blood test called glycosylated hemoglobin (hemoglobin A1c or A1c for short) was developed   This blood test could measure a person’s average blood sugar for the previous two and one-half months.  It didn’t require the person to be fasting to measure it.  A normal value was felt to be 6% or less.  Soon enough information was obtained to show that the lower the hemoglobin A1c was, the less likely the person was to have complications.  Initially, values of 10% or 12% percent were seen in some uncontrolled diabetics but diabetic control today is generally much better than that.  It appears that for the most part, patients that have a hemoglobin A1c of 7 % or less have many fewer complications than those that have higher values than that.  Recall, a normal hemoglobin A1c in a person that is not diabetic, is less than 6 %. 

            As any diabetic will tell you, trying to get the hemoglobin A1c down to 7% can be very difficult.  But researchers began to wonder if getting the hemoglobin A1C down to 6% wouldn’t prevent more complications than leaving a person with the abnormal value at 7%.  Diet and exercise can get a person’s hemoglobin A1C down some.  Various pills that a person takes (glipizide, metformin, pioglitazone, or sitagliptin) are four different medications that alone or in combination can have a marked effect in getting the hemoglobin A1c down.  But, it must be remembered that numbers recording a person’s blood sugar or A1c on a piece of paper are only a surrogate marker.  They are not “no heart attack, no stroke, no blindness, and no amputations”.   Before a medication can be certified useful, effective and safe, the medication has to do more than simply lower numbers for blood sugar.  The trial has to be done to show the medication actually stops heart attacks, strokes, premature death, etc.  Thus came the ACCORD trial described below.

            The National Heart, Lung and Blood Institute sponsored a large study looking at 10,000 diabetics to see if trying to get the hemoglobin A1c down to 6% or less would be beneficial.  The study was directed at an elderly group aged 62 years old on an average.  The individuals had to have cardiovascular complications at the time they entered the study to see if better diabetic control could saves lives.  The study is called the “Accord” Trial.  The method whereby the blood sugar was lowered was not stipulated in the test.  Physicians could use any means they wanted and many of them used insulin.

            The surprise result of the Accord Study was that tighter diabetic control led to more fatal heart attacks than did the comparison group that was treated in their conventional way.  Thus it seems that the tighter the diabetic control got, the more likely the person was to have a fatal heart attack.  Our media and television as always, spectacularized this study and made it sound as though good diabetic control could kill you. For those diabetics that don’t like diet, exercise and other medications, there was a ticket to say, “See! All those pills, diet, and exercise can kill you.”

Nothing could be farther from the truth.

            The fact is that multiple other studies over the years has shown that diabetic control is highly beneficial in stopping diabetic complications.  The only question that was being asked of the ACCORD trial was whether even tighter diabetic control would be better.  Unfortunately, the study was done on a group of  individuals who already had significant cardiac and vascular complications.  This is also a group that tends to have more cognitive impairment.  Trying to get tight diabetic control is very difficult and can be very frustrating.  The likelihood of getting low blood sugars becomes much greater.  Specifically, asking an elderly population to achieve tight diabetic control using insulin is probably counterproductive or even dangerous.  This was probably the reason the tight control group in the Accord Study had more mortalities than the group that was under routine care.

            But please don’t listen to those that say good diabetic control is not beneficial or may even be harmful.  Absolutely, diabetic treatment needs to be individualized for each person but there are certain facets that are critically important.  One of these is adequate control of cholesterol with an LDL (bad cholesterol) of 70 milligrams percent or less.  Total cholesterol should be way below 200 milligrams percent.  Blood pressures should be 120/80 or less.  The previous normal values of 140/90 that we adhered to until the year 2000 are outdated and associated with significant adverse effects on the diabetic.  Avoidance of cigarette abuse is critical.  Controlling the glycosylated hemoglobin to 7% has clearly been shown to be beneficial for the entire group of diabetics.  Trying to get it to 6% using insulin in an elderly population with some element of cognitive impairment is very likely not useful as shown in the Accord Study.

            Other large clinical trials called “ADVANCE” and Steno-2 indicate that better diabetic control getting a glycosylated hemoglobin as low as 6.4% is beneficial in preventing long term complications.  Thus, the adverse effects seen in the Accord Study are not being confirmed by other similar trials.  Getting the glycosylated hemoglobin as low as can be comfortably and safely done is definitely in the diabetic’s interest.

This and other columns available at www.macpierre.com.