About the Diabetes Unit
What is Diabetes?
MGH Diabetes Timelines
About the Diabetes Center
General Info / Directions
Diabetes Treatment Center
Clinical Research Center
Faculty & Staff
Program to Cure Diabetes
Type 1 Research
Type 2 Research
Clinical Trials
Research Faculty
  Diabetes Self Management Education Program
Articles of Interest
Support New Research

Diabetes is a disease caused by the loss of the ability to transport glucose into the cells of the body, either because not enough insulin is produced or because the response to insulin is weak.

In a healthy person, even a small rise in blood glucose stimulates the production and secretion of insulin, whose role is to increase glucose uptake into cells, returning the blood glucose to the optimal level. In diabetes, the blood stream may be awash with glucose, but it cannot reach the places where it is needed. The body can starve in the midst of plenty.


The treatments available today mean that diabetes is no longer a fatal disease. However, no treatment is able to replace the body's minute-to-minute production of insulin and precise control of glucose metabolism. Consequently, the blood glucose levels in diabetics are generally too high which, over time, causes an array of problems. Diabetes is the leading cause of blindness, amputation, renal failure, the premature development of heart disease or stroke, and causes the loss of one to two decades of life.

Diabetes is one of the most common chronic diseases in the world. In the United States, it affects more than 12% of the adult population over 45: a total of 18 million people. The number of new cases is increasing by about 1.2 million per year. In addition to those with clinical diabetes, there are approximately 40 million people who are midway between those who are normal and those who are clearly diabetic: they have abnormal glucose tolerance. Many of these will develop Type 2 diabetes in time and some estimates of the potential number of diabetics are as high as 36 million or 25-30% of the adult population over 45 years.

Diabetes and its complications have a major socioeconomic impact on modern society. Of the approximately trillion dollars spent on healthcare in the US today, roughly $132 billion are spent to treat diabetes and its complications. Since the incidence of diabetes is rising, the costs of diabetes care will occupy an ever-increasing fraction of total healthcare expenditures unless steps are taken promptly to meet the challenge. The medical, emotional and financial toll of diabetes is enormous, and increasing as the numbers of those suffering from diabetes grows.

Type 1 (Juvenile) Diabetes
Type 1 diabetes is an autoimmune disease, initiated by some event which triggers the immune system to react to and destroy the patient's insulin secreting cells, the beta cells in the pancreas. For many years, production of new beta cells is fast enough to stay ahead of destruction and a sufficient number of beta cells are present to control blood glucose levels. Slowly, the numbers of beta cells decline. When the number of beta cells drops to 10%, blood glucose levels can no longer be controlled and the progression to total failure of insulin production is almost inevitable. Despite this, it seems likely that the regeneration of beta cells continues for some years, even after insulin production ceases, but that the cells are destroyed as they develop maturity.

Research at Massachusetts General Hospital has resulted in the first ever cure of Type 1 diabetes in mice. The investigators hope that further research will enable this kind of treatment to cure patients with Type 1 diabetes. Click here for additional information on the search for a cure of Type 1 diabetes.

Type 2 Diabetes
The recently announced results of the Diabetes Prevention Program study has confirmed that the modern Western lifestyle of over-abundant food and little physical exercise increases the likelihood of developing Type 2 diabetes, the more common form of diabetes. In this Type, beta cell failure is almost always due to insulin resistance, an ineffective response to insulin. Consequently, the beta cells must secrete large quantities of insulin, in an attempt to maintain normal blood glucose.

Although the majority of individuals with insulin resistance are able to maintain high secretion rates throughout their life, perhaps one third develop a partial beta cell failure, resulting in the high blood glucose of Type 2 diabetes. In these cases, blood glucose can be lowered toward normal by limiting food intake, by improving physical conditioning, by reducing body weight and, in some cases, drugs. Since high levels of glucose are toxic to beta cells, their function declines progressively and many patients eventually need insulin.

Many questions remain about Type 2 diabetes. Why do some people acquire diabetes and not others? What genes are associated with the inherited predisposition to beta cell failure? What, in molecular and cellular terms, is insulin resistance? Scientists at MGH are working hard to find the answers to these questions and others. Click here for additional information on Type 2 Diabetes Research.

  © 2005 Massachusetts General Hospital     Disclaimer      Privacy Policy     Site Map