Matthew Gilbert, DO, MPH, an endocrinologist at the UVM Medical Center and associate professor at the Larner College of Medicine at the University of Vermont, brings us up to date about the difference between these two diseases, the range of treatment advances, and the new options and technologies available to patients. You can watch Dr. Gilbert’s Community Medical School lecture on this topic by clicking here.
What is Type 1 diabetes?
In general, Type 1 diabetes is an autoimmune disease—the body produces an antibody that attacks its own cells, in this case the beta cells within the pancreas. The beta cell is responsible for producing the insulin that keeps your blood sugar in a normal range throughout the day. So destruction of beta cells by the immune system leads to insulin deficiency and subsequently the development of Type 1 diabetes.
What is Type 2 diabetes?
The cause of Type 2 diabetes is far more complex. There is a genetic component, an underlying genetic susceptibility for developing Type 2 diabetes—which is why the disease seems to run in families. Other causes include “insulin resistance” and an “incretin defect.”
Skeletal muscle, fat cells, and the liver are all sensitive to insulin, and “insulin resistance” occurs when the body’s cells become resistant to the effects of insulin, leading to less uptake of glucose, or sugar, by the skeletal muscle and fat cells.
In addition to insulin resistance, patients with Type 2 diabetes also have an increased level of glucagon, which is a hormone produced in the pancreas and whose function is to increase production of glucose in the liver. This increased level of glucagon causes a significant increase of glucose production in the liver, an increase that is not in line with what the body is supposed to do on a regular basis.
Other hormones are released by our gut when eat—these hormones, known as incretin hormones, signal the pancreas to release insulin. In patients with Type 2 diabetes, there is an “incretin defect” where the level of certain incretin hormones are decreased or the hormones are not sending the correct signal to the pancreas.
What are the warning signs of diabetes?
One of the biggest challenges with regard to diagnosing Type 2 diabetes is that the vast majority of patients early in the disease are asymptomatic. Although we know that there are well-known risk factors for developing Type 2 diabetes (such as being sedentary,obesity, high cholesterol, and a family history of Type 2 diabetes) there is no one particular sign or symptom that can alert you that it’s time to be tested for diabetes. Patients cannot feel “insulin resistance,” or the “incretin defect,” or that there is too much glucagon circulating in the bloodstream.
The most common first symptoms are an increased thirst and urinating more frequently. These two symptoms can be signs that the person’s blood sugar is elevated, because one of the ways the body tries to get rid of excess blood sugar is through urination.
How does early diagnosis and intervention impact a patient’s health outlook?
Early diagnosis and intervention are critical to a patient’s long-term health. The current recommendations for clinical screening of patients involves either a blood test in the morning or a fasting blood sugar test. Another blood test, called a Hemoglobin A1c (or HbA1c), measures average blood sugar levels over a three-month period and is very effective for early diagnosis of diabetes. A more involved and less common screening test is the “oral glucose tolerance test,” which takes several hours and involves drinking a glucose solution.
Since it’s unusual for a clinician in the United States to see an adult patient who doesn’t have at least one of the risk factors for diabetes (family history, high cholesterol, sedentary lifestyle, obesity), clinicians should be screening patients for diabetes on a regular basis.
Early diagnosis of Type 1 or Type 2 diabetes is critical because of the “memory effect.” There is something about achieving excellent glycemic control early on in the disease that reduces the risk of developing complications from diabetes down the road. Some of the landmark clinical trials of both Type 1 and Type 2 diabetes have followed the participants over a 10-year period after the original trial ended and the research has shown that the participants who had better glucose control during the study had fewer complications later on.
What are some of the complications of diabetes?
The complication of diabetes are generally split into two groups, based on the size of the blood vessel that is damaged.
Macrovascular complications involve damage to the larger blood vessels, such as those that supply blood to your brain and can cause a stroke; those that supply blood to your heart and can cause a blockage or heart attack; or those that supply blood to your lower extremities and can cause foot ulcers or a lack of wound healing. These complications are often called peripheral vascular disease.
Microvascular complications are problems with the much smaller blood vessels, such as the blood vessels in the eye that can grow abnormally or rupture or bleed, leading to blindness from a condition called diabetic retinopathy. Other microvascular complications involve damage to the small vessels that supply blood to the kidney, which can cause kidney damage and lead to kidney failure, and the even smaller blood vessels that supply blood to the nerve endings, which can cause diabetic neuropathy, a condition when the nerves begin to die and cause pain and discomfort.
These are complications that we try to prevent by controlling blood sugar, blood pressure, and cholesterol levels and by encouraging patients to stop smoking and begin exercising. All of these combine to reduce a patient’s risk of developing a complication.
How can I reduce my risk for diabetes?
My patients often say, “Everyone in my family has diabetes, what do I do?” The reality is that if everyone in his or her family has diabetes, this patient also has a good chance of developing diabetes. But even so, there are things a patient can do to reduce that risk as much as possible, such as exercising regularly, doing resistance exercises like weightlifting, keeping at a healthy weight, watching what they eat, limiting simple carbohydrates, not smoking or stopping smoking. These are all things that people can do to try to reduce their risk as much as possible.
What are the treatment options for Type 1 diabetes?
If you were diagnosed with Type 1 diabetes before 2001, you had available two types of long-acting insulin and one type of short-acting insulin. Now, in 2018, there are numerous types of long-acting insulins and they are genetically engineered to mimic the normal function of the pancreas. Patients and their clinicians can select the most appropriate insulin from a list that includes long-acting, ultra-long acting, rapid-acting, and super-rapid-acting.
Not only do we have different insulins, but there are now different ways to deliver the insulin, including inhaled insulin and pre-filled insulin pens with much smaller needles, which eliminate the need to use an insulin syringe and a vial.
Insulin pumps continuously supply insulin on a regular basis through a catheter under the skin. The closed loop insulin pump uses a second new technology, called a continuous glucose monitor, which is a small receiver inserted with a catheter under the skin. The monitor provides a minute-by-minute check of the patient’s blood sugar and sends that information to the insulin pump, which then adjusts the insulin delivery on a minute-by-minute basis. As the person goes about his or her daily activities, the sensor is communicating with the pump and the the pump constantly adjusts insulin delivery to maintain normal levels. This is truly revolutionary. Continuous glucose monitors are also available for patients not on insulin pumps and may help eliminate the need for finger stick glucose testing.
What about treatment for Type 2 diabetes?
Before 2001, there were two classes of oral medication for patients with Type 2 diabetes. Now there are multiple classes and within each class are multiple different medications—since 2005 over40 new medications for treatment of Type 2 diabetes have been approved by the FDA.
One new class of medication is called the SGLT2 inhibitors. The medications in this class prevent glucose from being absorbed in the kidneys. As a result, they decrease glucose in the blood and cause it to spill into the urine.
In addition to oral medications, there are non-insulin injectable medications. The GLP-1 agonists increase insulin secretion from beta cells and suppress glucagon secretion; they can also slow gastric emptying and promote satiety.
Insulin pumps and continuous glucose monitors have also become available for patients with Type 2 diabetes.
This variety of treatment options provides so many different ways to treat Type 2 diabetes that we can be very successful with regard to lowering a patient’s blood sugar. Clinical trials have also shown that the new medications can help patients lose weight, reduce the frequency of low blood sugar events, and even protect the heart.
What does the future of treatment look like?
The future of diabetes treatment includes an “artificial pancreas,” which we should see in a few years. This device uses a continuous glucose monitor to enable it to adjust insulin on a minute-by-minute basis, including insulin boluses when the patient eats, and it will actually contain another hormone, glucagon, as a counterbalance if there is a low blood sugar reading. The patient will, actually, be wearing a “pancreas” on his or her belt to both control high blood sugar and prevent or treat low blood sugar.
It’s really an exciting time to be an endocrinologist and see the difference these technologies make in our patient’s lives and health outcomes.