Prevention of Type 1 Diabetes

Thomas Higgins, MD
6/26/00

Considerable effort is being expended world wide to eradicate type 1 diabetes. Currently, Type 1 diabetes occurs in approximately 0.5% of the general population in the United States with most cases occurring between 5 and 15 years of age. The disease is twice as common in Finland, occurs 10 times more commonly if a first degree relative already has the disease and occurs 30 to 50% of the time in both members of a set of identical twins.

As little as 20 years ago, type 1 diabetes was considered to be due to some unknown environmental factor or a pancreatic infection which destroyed islet cell function. It is now clear that the vast majority of patients with type 1 diabetes develop their illness due to an autoimmune process and that they have an underlying genetic predisposition to the illness. We know and can now detect the genes which both predispose an individual to type 1 diabetes and the genes which are protective for the disorder. We can also measure the antibodies associated with the autoimmune response causing Type 1 diabetes. These measurable antibodies aren’t the actual "villains" causing the destruction of the beta (insulin producing) cells in the pancreatic islets but rather are associated with the cellular immune (T Cell) response which is the actual culprit. During the prediabetic stage when the individual is clinically well but the autoimmune process is active, we can also detect subtle changes in insulin secretion.

Based on various combinations of the above measurements, we can predict who will develop Type 1 diabetes. The rapidity of development of Type 1 diabetes is quite variable and appears to be fastest in the younger patients. At this time we do not know if there is an environmental trigger which starts the autoimmune process or if it is related to a "biologic clock" which is primed to start at a particular time in a person predisposed to the disease.

Wide spread screening of the population for individuals predisposed to develop type 1 diabetes is feasible but is awaiting safe & effective methods which are proven to protect against the disease. After all, why screen if you can’t do anything to prevent the disorder. Currently there are several promising studies looking at the prevention of Type 1 diabetes.

There are human studies of nicotinamide, a free radical scavenger, which has been effective in preventing type 1 diabetes in mice.
Exposure to cow’s milk during the first 6 months of life has been epidemiologically associated with type 1 diabetes and avoidance of cow’s milk during this time is being evaluated as a preventative measure.
Early aggressive treatment of type 1 diabetes with insulin is often associated with a prolonged ‘honeymoon phase’. More recently, the use of insulin prior to the development of type 1 diabetes seems to prevent progression of the autoimmune response which causes type 1 diabetes. Studies are now underway looking at injected, oral and inhaled insulin to prevent type 1 diabetes.

There are sure to be future additional modalities evaluated in clinical trials for the prevention of type 1 diabetes.

Successful completion of the ongoing and future diabetes prevention trials will pave the way for large scale population screening for persons predisposed to develop type 1 diabetes. It is hoped that preventative treatment will be associated with a reduction in the frequency of this disorder.