This video will address the role of the exercise, in the prevention and treatment for diabetes. As 90 to 95% of all diabetics have type 2 diabetes, I will focus on this condition today. Type 2 diabetes, once known as adult-onset, or non-insulin-dependent diabetes. Is a condition characterized by chronic hyperglycemia, or elevated blood glucose levels. It is no longer referred to as adult-onset diabetes, as a consequence of the increase in childhood obesity. And the subsequent development of type 2 diabetes in children. As we'll see, the primary cause for type 2 diabetes is the development of insulin resistance. If an individual's fasting blood glucose levels are below 100 milligrams of glucose per deciliter of blood, then they are considered normal. Blood glucose readings between 100 and 125 milligrams per deciliter are defined as pre-diabetic. Fasting levels of 126 milligrams per deciliter or greater, are classified as full diabetes. The incidence of diabetes has risen exponentially over the past two decades. In the United States alone, approximately 30 million people have diabetes, another 60 million people are pre-diabetic. Not surprisingly, the prevalence of type 2 diabetes closely tracks that for increase in rates of obesity. As discussed in the video on obesity, the accumulation of visceral fat located within the abdominal cavity. That surrounds important internal organs, can lead to insulin resistance, and thus type 2 diabetes. Common symptoms for type 2 diabetes include thirst, frequent urination. Fatigue, slow-healing sores, and frequent infections, and blurred vision. The complications associated with type 2 diabetes are very serious, and many. There is a 5 to 30-fold increased risk of retinopathy, with eventual blindness. Nephporathy, or kidney disease, neuropathy, or diabetic nerve pain, and lower limb amputations. Further, I have discussed the added risk for diabetics, for coronary heart disease and stroke, in the previous video. When looking at the modifiable risk factors for developing type 2 diabetes. You will find physical inactivity at the top of the list, along with obesity. Other modifiable risk factors include hypertension, and elevated cholesterol levels. A family history of diabetes, ethnicity, along with advancing age, are other risk factors for developing type 2 diabetes. As previously stated, the primary cause of type 2 diabetes is the development of insulin resistance. When insulin binds to its receptor, located on the surface of the cell membrane. It generates an intracellular signal that opens channels in the membrane, that allows glucose in the blood to enter into the cell. It is believed that the abnormalities in this signal transduction pathway are responsible for the development of insulin resistance. As skeletal muscle is the major depot for blood glucose, after a meal. Insulin resistance in muscle will result in chronically-elevated blood glucose levels, and hyperglycemia. Diagnosis of insulin resistance can be performed by an oral glucose tolerance test. In which after fasting overnight, the individual consumes a glucose drink. And the rate in which glucose is cleared from the blood is measured over time. A non-diabetic individual will clear the glucose within 90 minutes. While a diabetic subject will take significantly longer, as a result of insulin's inability to effectively promote glucose uptake. Regular exercise can help with the prevention and treatment of type 2 diabetes in two ways. First, a single bout of exercise can significantly lower glucose levels in the diabetic. Second, regular exercise will increase insulin sensitivity in muscle, thereby decreasing insulin resistance. As discussed in the Carbohydrate video, a single bout of exercise will promote blood glucose uptake by active muscles. This holds true for diabetic individuals as well. As shown here, diabetic subjects monitoring their condition, or in control, still have elevated resting blood glucose levels. However, please notice the significant blood glucose-lowering effects from just one bout of prolonged exercise. Continued muscular contractions stimulate the extraction of glucose from the blood for fuel, thereby normalizing blood glucose levels. The second benefit of exercise, for the diabetic, relates to the improvement in insulin sensitivity. A single bout of the aerobic exercise will increase insulin sensitivity in skeletal muscle immediately after exercise. And can persist for several hours, post-exercise. Notice that all ten subjects demonstrated an increase in insulin sensitivity after exercise, when compared to resting values. Similar findings have also been reported for strength training. After 16 weeks of strength training, improvements in insulin sensitivity were found in all subjects tested. Thus, regular participation in all forms of exercise will have this dramatic effect of reducing insulin resistance in all populations. Contributing to both the prevention and treatment of type 2 diabetes. There is no pill, medication, or other medical procedure that can come close to this health benefit of exercise. Thus, it should come as no surprise that the incidents of type 2 diabetes is inversely related to the frequency of exercise. This relationship holds true for overweight and obese individuals, who are at a greater risk for developing type 2 diabetes. In fact, regular excercise is particularly beneficial for individuals who are at a higher risk of developing type 2 diabetes. As a result of having multiple risk factors, such as hypertension, a family history of diabetes, and obesity. Such individuals can decrease their risk of developing type 2 diabetes by as much as 50% with regular exercise. In summary, 90 to 95% of diabetics have Type 2 diabetes. Which is characterized by increasing insulin resistance, resulting in hyperglycemia. There are numerous health consequences associated with diabetes. A single bout of exercise can help to normalize blood glucose levels. The benefits of regular exercise for the type 2 diabetic include an increase in insulin sensitivity, or a reduction in insulin resistance. No pill can come close to these effects of exercise.
