Last week I wrote about one of the problems facing Type 1 diabetics: the ever increasing cost of the insulin they need to stay alive. Today, I am writing about some good news that may reduce the need for insulin. Dr. Diane Faustman of the Massachusetts General Hospital and Harvard Medical School has been for many years a leading researcher into novel ways to treat diabetes. For the last 10 years she has been studying the effects of a generic vaccine for tuberculosis on people with longstanding Type 1 diabetes.
As many of you already know, Type 1 diabetes is an autoimmune disease in which the body’s immune system attacks and kills the pancreatic cells which manufacture insulin. Insulin is what enables the body to use the glucose (sugar) in the bloodstream and deliver it to the cells which need it to operate. Without insulin, the body cannot use the glucose and the patient will ultimately die. Dr. Faustman and her colleagues have been exploring ways to shut down the immune system attacks on the insulin producing cells in the hope that there may still be some residual ability of the body to manufacture insulin, even in people who have had Type 1 diabetes for many years. Results in mice were promising and recently Dr. Faustman and her colleagues reported on the results of the most recent human studies.
They found that two doses four weeks apart of a TB vaccine, BCG, that has been around for almost 100 years has a powerful effect on the immune system and on the body’s glucose metabolism system. The effects did not appear for three years but when they did, they were dramatic and exciting.
In the first place, the average blood glucose levels for those who received the treatment went down significantly. The closer to normal the blood glucose levels are, the fewer long-term consequences will result from the diabetes. Type 1 diabetics use insulin to keep their blood sugar levels down. One of the risks of insulin therapy, however, is that the patient will accidentally get too much insulin and blood sugars will drop below normal. This is a condition called hypoglycemia and it can be fatal, if the blood glucose level drops too low and is not promptly corrected. Some studies have found that fully 1 out of every 20 Type 1 diabetics dies in his or her sleep due to accidental hypoglycemia.
The report of Dr. Faustman’s group found that the number of hypoglycemic events in the treated patients went to essentially zero, even though blood sugars were much lower and closer to normal. For most Type 1 diabetics using insulin today, there is a risk that, in keeping blood sugars close to normal, they will accidentally drive them too low and become hypoglycemic. To reduce the incidence of hypoglycemia in these patients at the same time blood sugars are reduced to near normal is a big deal.
The study did not find that these patients no longer needed insulin but they needed less than before the vaccinations. The question of whether the patients are making insulin on their own remains open. The study also found that the way in which the body used the glucose in the blood was changed by the vaccinations so that, when there was more glucose, the body used more and, when there was less glucose, the body used less. The researchers believe this change in cellular biology accounts for the reduced need for insulin, the improved blood sugar control and the near elimination of hypoglycemic events.
There is much more work to be done before researchers know the limits of the use of this vaccine and the best way to use it. This is certainly not a cure for Type 1 diabetes but it is a big step in that direction. Thank you to Dr. Faustman and all the researchers who are working in this field.
