In the past seven years, we have gained a better understanding of the relationship between blood sugar and the development of diabetic complications. Two recent research trials have shown us that controlling your blood sugar can prevent or slow the development of diabetic complications. This research has also allowed physicians to make recommendations regarding blood sugar levels.
Type 1 diabetes
Does controlling your blood sugar prevent the complications of diabetes including eye disease, kidney problems, nerve damage, and heart disease? Two research trials that tried to answer this question were published in the 1990’s.
The first trial, The Diabetes Control and Complications Trial (DCCT), was a study that lasted almost ten years and enrolled patients with Type 1 Diabetes to receive either conventional therapy or intensive therapy. Intensive therapy was given with the hope of keeping blood sugar levels as close to normal as possible by giving three to four injections of insulin daily. For the intensive therapy group of patients, the average HbA1c was 7.2%, compared to the HbA1c of 9% in the conventional therapy group.
On average the blood sugar in the intensive therapy group was 150 mg/dl and 230 mg/dl for the conventional group. For those patients that had near normal blood sugars in the intensive therapy group, their risk of developing diabetic complications was reduced by 27 to 76 percent.
The investigators involved in the DCCT concluded that for patients with Type 1 Diabetes, blood sugars that are as close to normal as possible (average HbA1c of 7.2%, average blood sugar value of 150 mg/dl) would help to reduce the chances of developing diabetic complications.
Type 2 Diabetes
After the DCCT, the question still remained, did tight blood sugar control prevent complications with patients with Type 2 Diabetes? A large trial in England called the United Kingdom Prospective Diabetes Study (UKPDS) was performed to answer this question. The study followed more than 5,200 newly diagnosed people with Type 2 Diabetes on average for ten years.
Like the DCCT, there was an intensive therapy group and a conventional therapy group. Patients in the intensive therapy group achieved a HbA1c of 7.0% and patients in the conventional therapy group had HbA1c of 8.0%. Results in the UKPDS were dramatic.
Patients in the intensive therapy arm showed slower progression of diabetic eye disease, diabetic kidney disease, and lowered their risk of having a heart attack. The benefit of tighter control of blood sugar occurred no matter which drug was used to treat the patient (glyburide or insulin). For overweight patients the use of metformin (Glucophage) was found to lower the risk of heart disease and stroke.
This study concluded that near normal blood sugar levels reduced the chance of small and large vessel disease in patients with Type 2 Diabetes. As a result of these two landmark trials, the American Diabetes Association (ADA) has emphasized that the targets for HbA1c and blood sugars should be as close to normal as possible.
Is your blood sugar tightly controlled?
Treatment for patients with Type 1 and 2 Diabetes needs to focus on appropriate meal planning and exercise. Glucose lowering agents in the form of pills and/or insulin should be added to meal planning and exercise to achieve the target blood sugar goal. The type of diabetic medication or insulin that you may be prescribed will vary from individual to individual. With the newer agents on the market and the multiple combinations that can be created, each individual may benefit from a different antidiabetic regimen.
In checking your blood sugars, if you note a consistent pattern of blood sugars greater than 120 mg/dl in the morning or at bedtime, you should contact your doctor to discuss if any action is necessary. Increasing your medication, changing your lifestyle, or increasing insulin may be required to achieve the ADA goals for blood sugar.
Discuss what blood glucose levels are best for you with your doctor. Very tightly controlled blood sugar may not be appropriate. For example, patients with other serious diseases and a very short life expectancy may not be recommended to achieve a blood sugar that is as close to normal as possible.
Patients who are unaware when they have too low a blood sugar (hypoglycemia) in these cases, risk low blood sugar reactions when trying to control blood sugar.It may not outweigh the benefit of achieving tighter blood sugar levels.
Questions for your doctor
You may want to ask your doctor if you are a candidate for intensive therapy. Please share the goals for suggested blood glucose values with your doctor. You may want to ask your doctor to refer you to a certified diabetes educator to teach you how to monitor your blood sugars and to discuss appropriate meal planning and exercise regimens. If your blood sugar values are not near the suggested targets, you may want to ask your doctor about appropriate medications or changes in your regimen to improve your blood sugar control.
Conclusion
Managing diabetes has become a fine art. New medications and forms of insulin are now available to make it easier to achieve near normal blood sugars. New research has confirmed that as close to normal blood sugar control as possible will reduce the risk of developing complications of diabetes, including heart disease, kidney disease, and eye disease. Know your goals, know your numbers and talk to your doctor about helping you to achieve the best diabetes care.
