Over 15 years ago the Diabetes Control and Complications Trial, also fondly known as the DCCT came out with results that proved what doctors had been preaching for years: aggressive control of blood sugar decreases complications including vision complications.
Higher than normal blood glucose levels damage the blood vessels in the retina and cause leakage into the macula the part of the eye that those the fine “HD” vision. This is called diabetic macular edema, a common cause of legal blindness. It can further lead to abnormal blood vessel growth which bleeds and can result in a blind painful eye.
In the past few months the data from the patients that participated in the trial has been reviewed to see what happened to them. The original trial had one group of about 700 patients that looked after their blood glucose the conventional way and a second group that was encouraged to have tight control of their glucose with frequent self monitoring of glucose, multiple insulin shots every day, insulin pumps and nutrition and exercise routines. This made quite a difference in the glucose readings between the two groups. The average for the intensive therapy patients was 155mg/dl versus 231mg/dl in the laissez faire group. The patients in the intensive treatment group reduced their risk for developing retinopathy by 74% and if they already had retinopathy the intensive therapy group slowed the progression by about 50%.
Now fast forward to 2003. The patients went about their lives without the supervision they had had during the trial. Analysis of their glucose showed that there was no difference in the levels between either group. In fact the conventional group’s average glucose went down and the intensive therapy group went up so that they met in the middle.
The fascinating finding though, was that the intensive therapy group still was better off in terms of having fewer complications. This is similar to people who misuse credit cards or maybe whole countries that misuse credit! When you overspend on your credit card or housing market and then become more responsible, you will still be behind those people who were more careful with their money.
The bottom line of course is that the sooner a patient gets control of the blood sugar the less damage that will have been done.