The Science Behind Diabetes Mellitus

Nearly 3,000 years ago, Egyptian scholars chronicled a rare disease characterized by an excess of urine production. Then, around 113 AD, Aretaeus of Cappadocia described the same symptoms and gave the condition the name “diabetes.” The term, roughly translated, means “to pass through” referencing the act of passing urine through the system. The term “mellitus” (meaning “honey sweet”) was coined in 1675 by Thomas Willis after rediscovering the sweetness of urine (the first discovery of this symptom was chronicled by Indian physician, Sushruta, in 7th century BC.) In 1776, physician Matthew Dobson demonstrated that the sweetness was due to the presence of sugar.

The symptoms of diabetes were well-documented, but the cause was unknown. Many believed it to be an affliction of the lungs or heart. Finally, in the 1800s, a breakthrough occurred. The French physiologist, Claude Bernard, through his work with dogs, found that the liver played a role in glucose production and concluded that it was an excess of glucose, secreted by the liver, that caused diabetes. Soon thereafter, Minkowski and Von Mering discovered the role of the pancreas in secretion and maintenance of glucose homeostasis. Their work led directly to the discovery of insulin by Banting, Best and Macleod in 1923.

Today, diabetes mellitus is much more common than when it was first discovered. Diabetes currently affects 20 million Americans and that number is expected to increase to 55 million by 2030 (projected to be 15% of the population.) The cost of diabetes is expected to rise to $622 billion per year. Its prevalence will continue to increase due to a number of factors:

1. Diabetes management has improved, meaning that those afflicted will live longer;
2. An aging population, in general, will result in higher incidence rate;
3. Increases in population of African Americans and Hispanics who are at a higher risk for the disease;
4. The dramatic increase in diabetes in children and adolescents.

As the incidence of the disease increases year-by-year, understanding it becomes much more significant. It’s important to note that no one is immune. There is no vaccine or medicine to prevent it and once developed, it is incurable. It’s the boogeyman waiting in the cupboard that we reach into every day. How does it begin? How do we recognize it? And, should it develop, how do we live with it?

Diabetes Mellitus affects the way a body absorbs sugar and is characterized by a high blood glucose level. Over time, high glucose levels can cause multiple serious health problems. As a person eats, food is digested in the stomach to produce a type of sugar called glucose. The stomach and small intestine absorb the glucose and it is released into the bloodstream. The blood glucose level is regulated by beta cells located in the pancreas. Beta cells monitor the amount of glucose in the bloodstream and if the level is high, the beta cells create insulin which is then secreted by the pancreas into the bloodstream. Insulin travels through the bloodstream to cells to allow them to absorb glucose for immediate use or storage. As glucose levels drop, the beta cells slow the creation of insulin and the pancreas slows secretion. If glucose levels are too low, insulin is released and the liver begins to manufacture glucose. The liver acts as a storage system and manufacturer of glucose through a process called glycogenolysis. A body’s normal blood glucose level is between 70 and 120 milligrams per deciliter.

Diabetes develops when the body loses the ability to produce insulin, produces too little or if cells have trouble using the insulin produced. This leads to high blood sugar, a condition known as hyperglycemia. As the blood sugar level rises, the kidneys look to get rid of the extra sugar through urine. This causes high thirst, fatigue, weight loss and constant hunger due to the loss of energy (sugar) and water.

Symptoms of diabetes are numerous, but the most common include: thirst, increased urination, fatigue, blurred vision, numbness in extremities, sores that do not heal and weight loss. They may start quickly or develop slowly, and can be so mild that a person may not notice them until larger health problems develop, such as loss of vision or heart disease.

Diabetes comes in different forms. The outcomes and symptoms are similar, but the disease can develop in multiple ways and each type is characterized by its specific form of genesis. Type 1 diabetes is characterized by an immune system run rampant – the immune system attacks and kills the beta cells necessary for insulin production. As a result, symptoms develop quickly. Genetics plays a large role in the development of type 1 diabetes and scientists have found that people who have a particular HLA (human leukocyte antigen) complex are at greater risk. Still, the disease will not develop if not for a certain environmental factor – namely, a virus. If a person is infected with a virus that contains antigens similar to that of beta cells, the immune system will become confused – not able to determine which cells are the virus and which are the beta cells. The body will attack both. The most common viruses that contain antigens similar to beta cells are the German measles, mumps and rotavirus.

Type 2 diabetes – the most common form – is mainly caused by lifestyle factors. This form of the disease is brought about by obesity, poor nutrition and lack of exercise. In the majority of type 2 cases, the problem is an inverse of the type 1 situation. Instead of beta cells not producing insulin, body cells have trouble absorbing insulin which leads to cellular insulin resistance. In order to compensate for this resistance, beta cells work overtime to produce more insulin; in time, the cellular resistance becomes too much for the beta cells to handle.

Science has recently determined how obesity and lack of exercise relates to insulin resistance. Overeating stresses the inside of cells, specifically the membranous network called the endoplasmic reticulum (ER). When the ER is overloaded with nutrients, it causes the cell to close or dampen insulin receptors on the cell surface – the cell is full and can take no more. This causes the glucose level in the blood to rise. Physical activity can counteract this process by using up the nutrients in the cells, opening the insulin “gates” to allow more glucose in. Over-eating coupled with low physical activity compounds the problem and type 2 diabetes develops.

A third type, gestational diabetes, develops during pregnancy and is caused by hormonal changes. Hormones produced by the placenta cause insulin resistance in all women and most can produce enough insulin to overcome the resistance. Some cannot, and diabetes develops. Women who are obese or genetically prone to the disease are at higher risk. Other causes of diabetes are genetic mutations, cystic fibrosis, Cushing’s syndrome, hyperthyroidism and pancreatic cancer.

If left untreated, the effects of diabetes can be devastating. A constant high blood sugar level can modify proteins found in blood vessel walls, narrowing and weakening them, raising blood pressure. This leads to cardiovascular disease, hypertension, nerve damage and kidney disease. It can also lead to blindness. Diabetic retinopathy occurs when normal blood vessel walls in the eye are weakened and hemorrhages occur. To compensate, new fragile blood vessels are created and can bleed into the gel-filled portion of the eye. Scarring can occur causing retinal detachment and loss of vision. Diabetics are also at a higher risk of developing glaucoma or cataracts.

And if all of the aforementioned damage wasn’t enough, diabetics may lose immune function in their lower limbs, necessitating amputation. Lack of adequate blood supply can change the physiology of skin, causing ulcers that refuse to heal and which worsen over time. The only cure is removal of the lower leg.

Diabetes mellitus is serious and should not be overlooked. The most important thing is to diagnose it early enough to avoid all the future health hazards it causes. This affliction is quickly becoming a part of life for more and more Americans. The World Health Organization (WHO) predicts that in ten years, diabetes mellitus will become the seventh most deadly disease throughout the world. Sedentary lifestyles and poor nutrition choices do have consequences. Our bodies were meant for movement – so much so, that our ancestors had to be fit in order to survive, to hunt and avoid external threats. This is still true, only the source of the threat has changed. We have to be physically active and make better nutritional choices to avoid a new internal threat. It is estimated that currently, 86 million people have “prediabetes.” This condition is characterized by a higher than normal blood sugar content, but one not high enough to be called full-blown diabetes. It is a precursor to the condition and a warning sign. Do you feel healthy enough, honestly, to exclude yourself from this group?

Treatment

Diabetes mellitus is becoming a common ailment and treatments have been improving throughout recent years in an attempt to help those afflicted and, perhaps, find a cure.

Common Treatments

1. Lifestyle Change: Those with prediabetes or diabetes must be more active and eat more nutritious food. Foods with high sugar and fat content should be avoided completely – that donut or soft drink may sound good, but has to be avoided. Your life is literally at stake.
2. Insulin: This is mandatory for those with type 1 diabetes. Those with type 2 can avoid it with a change in lifestyle. Insulin may be delivered via needle, pump, disposable pen or inhaler. Blood sugar content must be constantly monitored.
3. Medications: Those with type 2 diabetes can avoid insulin through different medications such as Metformin that can make the body’s natural insulin more effective. Other oral medications help enhance the effect of Metformin.
4. Bariatric Surgery: These procedures (such as gastric bypass) can help those with type 1 and type 2 diabetes who are obese. Weight loss can help get blood sugar levels under control and make physical activity easier.

Future Treatments

1. Beta Cell Transplant: Scientists are working on a way to transplant working beta cells from a healthy pancreas to treat type 1 diabetes. In order to keep the body from rejecting the cells, the Diabetes Research Institute has developed a way to protect the cells with a barrier. Two years ago, it was announced that the first patient treated in this way no longer needed insulin.
2. Cell Therapy: This treatment involves reprogramming other body cells to become a beta cell and then transplanting them onto the pancreas. Multiple companies are working on the problem, finding success by morphing cells from the liver, pancreas or small intestine into the cells needed by the type 1-afflicted. Human trials have not yet begun.
3. Immunotherapy: Two companies are using immunotherapy in different ways. This involves teaching the immune system to avoid killing the important beta cells by introduction of foreign antibodies and lowering the level of a certain inflammatory protein.
4. The Artificial Pancreas: Currently still in development, this external device constantly measures the amount of sugar in the bloodstream and injects insulin when needed. It takes all of the guesswork and human error out of treatment.
5. Changing the Microbiome: An unbalanced microbiome condition known as dysbiosis has been found in patients with diabetes and can be effectively cured by fecal transplants. In patients, this has resulted in a short-term improvement of the insulin resistance found in those with type 2 diabetes.
6. GlucoTrack: This device (already available in Europe) can measure the amount of glucose in the bloodstream using electromagnetic waves, avoiding the needle altogether. Every day, better and better measurement devices are hitting the market.
7. Microchips and Nanobots: These are only speculations. Some researchers are looking into microchips that can diagnose prediabetes or nanobots in the bloodstream that can measure glucose levels and deliver insulin.

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