The Diabetes Epidemic
The disease, for which there is currently no cure, exacts a tremendous toll on patients, their families, and society. Diabetes, even when carefully controlled with conventional therapies, negatively impacts both the lifespan and quality of life for millions of people.
The International Diabetes Federation, or IDF, estimates that in 2015 approximately 415 million people had diabetes worldwide and that by 2040, this will increase to 642 million people worldwide.
In the United States, more than 29 million people, or approximately 9% of the U.S. population, suffer from diabetes, and 86 million are living with prediabetes, a serious health condition that increases a person’s risk of type 2 diabetes and other chronic diseases, according to the Centers for Disease Control and Prevention. According to the American Diabetes Association, the total costs of diagnosed diabetes in the U.S. rose dramatically from $174 billion in 2007 to $245 billion in 2012. This includes $176 billion in direct medical costs and $69 billion in reduced productivity.
Of the total population with diabetes, approximately 5%, or almost 1.5 million people in the U.S., have type 1 diabetes (T1D). In 2010, it was estimated that the annual cost of T1D to the U.S. healthcare system was approximately $14.4 billion.
What is Diabetes?
Diabetes mellitus, or simply diabetes, is a group of diseases characterized by high blood glucose (a.k.a., high blood sugar or hyperglycemia) that results from defects in the body’s ability to produce and/or use the hormone insulin. With the advent of, and improvements in, pharmaceutical insulin over the last century, the issue has become less so chronically high blood sugar, but instead blood sugar that must always be monitored, and for most diabetic patients is extremely difficult to sufficiently control, leading to numerous challenges, and sometimes fatal outcomes.
The role of insulin, which is produced by the endocrine beta cells in the pancreas, is to bind to receptors throughout the body to enable glucose (sugar) to be transported into the body’s cells for energy.
Normally, dietary carbohydrates (sugars and starches), which our bodies require for energy, are digested in the gastrointestinal track where they are converted into simple sugars, such as glucose. Glucose in the bloodstream stimulates the pancreas to produce insulin, and insulin allows glucose to be utilized in cells of the body, such as in the muscle for use or storage, in the liver for storage as glycogen, and in the adipose tissue for storage as fat.
Without insulin or the ability to use insulin, the body cannot use glucose normally, and glucose begins to build up in the bloodstream.
Types of Diabetes
In individuals with type 1 diabetes (T1D), the pancreas is unable to produce sufficient quantities of insulin. T1D is an auto-immune disease in which the body’s immune system mistakenly mounts an attack against its own healthy beta cells and destroys them. The onset of this form of the disease typically occurs in children and young adults, and T1D was formerly known as juvenile-onset diabetes, although it may be diagnosed, albeit less commonly, in older individuals. Once the insulin-producing beta cells have been attacked and destroyed, they never grow back. Spontaneous recovery is virtually unheard of with T1D.
In persons with type 2 diabetes, the body’s cells lose the ability to use insulin effectively, becoming insulin-resistant. Similar to patients with type 1 diabetes, glucose becomes trapped in the bloodstream. In some individuals with type 2 diabetes, the beta cells in the pancreas eventually stop functioning, and these patients require insulin injections to control their blood sugar levels.
Diabetes is a chronic disease that can be controlled but currently has no cure. The exact causes are not known. Symptoms of untreated diabetes include excessive thirst, extreme hunger, weight loss, feeling week or tired, blurred vision, frequent urination, itching, yeast infections, changes in the blood vessels, especially at the back of the eyes and lower legs, tingling or numbness in the legs or feet, and skin infections or slow healing wounds.
Treating Diabetes with Insulin
The current treatment for type 1 diabetes, and some type 2 diabetes, is constant monitoring of blood glucose and a highly controlled diet, coupled with multiple daily insulin injections.
Despite the use of insulin and advances in its delivery, pharmaceutical insulin injections cannot replicate the level of feedback control afforded by naturally occuring intact beta cells. Even with the most diligent insulin use, the adverse short- and long-term effects of diabetes include life-threatening episodes of low blood sugar, nerve damage, blindness, kidney damage, erectile dysfunction, foot ulcers leading to amputations, and cardiovascular disease. Research has shown that on average, the life expectancy of a person with T1D is reduced by approximately 12 years when compared to the general population.
Goal: A Replacement Pancreas
For type 1 diabetes, and type 2 diabetes where beta cells no longer function properly, the ideal therapy is to replace lost beta cells that resided in the pancreas. Not only would this approach eliminate the need for constant pharmaceutical insulin injections but also eliminate the need for constant glucose monitoring as the “replacement pancreas” would produce insulin and other factors in a real-time, physiological-true manner. By acting more like a real pancreas, the beta cell replacement therapy not only greatly improves the patient’s lifestyle, but should also reduce the risk for long-term diabetic complications. Such a product would transform the diabetes treatment landscape and begin to replace pharmaceutical insulin as the preferred long-term treatment option.
Transplantation of deceased donor-derived pancreas cells has produced a major advancement in the treatment of diabetes. These treatments cannot meet the clinical demand, however, due to limitations in the donor organ supply. In addition, transplant recipients must undergo lifelong immunosuppressive therapy, which increases the risk of developing infections and cancers. Despite the use of immunosuppression to promote survival of transplanted cadaver cells, the cells are ultimately attacked by the host immune system.