The Dish on Diabetes
When studying medicine, you become intricately familiar with the various organs and systems of the body. One of my favourite organs is the pancreas, a tadpole-shaped structure that lies behind the stomach and connects to the first part of the small intestine (the duodenum). The pancreas is a mighty little complex powerhouse that has numerous functions essential to the body. It provides digestive enzymes to facilitate breakdown of carbohydrates, protein and fats, and secretes bicarbonate in its ductal network to neutralize the acidic juices as food passes into the small intestine from the stomach.
One of the most interesting functions of the pancreas, however, has to do with blood sugar control, as part of the endocrine system. Contained within the pancreas are specialized cells, known as beta-cells, that produce and release insulin. Insulin is a small compound that acts in a similar fashion to a key, unlocking the ‘doors’ (transporters) on cells to allow glucose to enter and be used as an energy source. Every cell in the body subsequently has a specialized lock (receptor) on its surface that interacts with insulin to facilitate this process and lower blood sugar levels. Without these two essential components of the system, the body cannot properly use its primary energy source to fuel essential organs, such as skeletal muscle, heart and brain.
Diabetes mellitus occurs when there is a dysfunction of either the key or the lock within this system. Type I diabetes, typically with an onset in childhood, occurs when the pancreas fails to produce enough insulin keys to unlock the door that allows glucose to enter the cell. This is due to an autoimmune reaction, where the body’s own immune defence system begins to destroy the beta cells in the pancreas, causing an absolute insulin deficiency. Type II diabetes occurs when there is a problem with the lock on the surface of the cell that prevents insulin from unlocking the door. This is known as insulin-resistance, typically associated with a family history of type II diabetes, a diet high in carbohydrates and fats, and a sedentary lifestyle. Unfortunately, once a disease of adulthood, we are seeing increasing cases of type II diabetes in children as well. In both types of diabetes, the end result is a persistent elevation of the blood glucose levels.
But why do we care about high blood sugar?
An absolute insulin deficiency, such as that found within Type I diabetes, is in fact a medical emergency as it can lead to a life threatening condition known as diabetic ketoacidosis (or ‘DKA’) when untreated. More chronically, however, elevated levels of glucose in the bloodstream have damaging effects on blood vessels and can lead to cholesterol plaques within arteries, known as atherosclerosis. This affects both large and small vessels, increasing the risk of stroke, heart attack, renal injury, blindness, loss of sensation in the feet, poor wound healing, amputations and recurrent infections. As you can imagine, this can have severe consequences on quality and longevity of life.
Symptoms & Treatment
Classic symptoms of diabetes include excessive and prolonged thirst with increased urination (in volume and frequency) and hunger. The treatment for type I diabetes is replacement of insulin, an essential hormone within the body. For type II diabetes, a multi-dimensional treatment approach usually works best, involving lifestyle changes and pharmacology. This includes maintaining a diet low in carbohydrates and saturated fat, with lots of leafy greens, protein and unsaturated fats, otherwise known as the ‘Mediterranean Diet’. Furthermore, exercise is key in helping to regulate blood sugars in type II diabetes, with the best effects seen with at least 150 minutes per week of moderate to vigorous exercise (meaning the heart rate should elevate). While there is no prevention for type I diabetes, healthy diet and exercise can have extremely positive effects on warding off the onset of type II diabetes in susceptible individuals, a growing epidemic in North America.
While diabetes is a chronic disease, the good news is there are healthcare teams available to help control it. With the support of physicians, dieticians, optometrists, nurses and pharmacists diabetes can be managed so that people are able to achieve happy and healthy lives!
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