There are three main types of Diabetes: Type I, Type II, and Gestational Diabetes. They are separate diseases, but all have one thing in common: a high blood sugar caused by an insufficient amount of insulin. In this overview, I will break down a large amount of information into “chapters” so that you can more effectively digest it.
Insulin is a hormone that is essential for life for two reasons: a small amount is needed to keep fat cells from breaking down and building up in the blood, and a larger amount is needed to maintain normal blood sugar levels. Insulin is produced by specialized cells in the pancreas, called beta cells. Insulin enables the sugar (glucose) to move from the blood stream where it cannot be used into the body’s cells where it is used as to enable the cell to function. If sufficient sugar cannot get into the cell, it will die. In all three Types of Diabetes, the body cannot make enough insulin to transport enough sugar out of the blood and consequently the blood sugar will rise above normal levels.
Symptoms of High Blood Sugar
A high blood sugar will be filtered by the kidney which takes quite a bit of excess water with it when it is excreted into the urine. As a result, a person with high sugar will notice an increase in urination and start to become dehydrated. In the early stages, he will become thirsty, and be able to drink sufficient fluids to keep up with the loss. As the process continues, he will lose vital elements, called electrolytes and this will cause him to become tired. As the electrolytes become more imbalanced, he may become confused, have leg cramps, and may even have a disturbance in his heart rhythm. If the sugar is high enough, it may distort the shape of the lens of the eye leading to blurry vision. Because the cells do not have enough sugar, he may notice weight loss despite a good appetite.
Type 1 Diabetes – Overview
Diabetes mellitus Type I was originally called Juvenile Diabetes because it almost always occurred in children. Unlike Diabetes Mellitus type II which will be discussed later, it is an auto immune disease in which the cells that produce insulin are destroyed. While the destruction process of these beta cells( which are housed in the pancreas) can take many years, the symptoms come on suddenly. By the time the person has symptoms, from high blood sugar, he has almost no insulin. When this happens, the person’s blood sugar rises to very high levels, and the individual suddenly feels extremely ill. Insulin is also needed to keep fat cells from breaking down. While the body requires very little insulin to keep fat cells from breaking down, people with type I diabetes have no or almost no insulin. As fat cells break down into fatty acids, they produce ketone bodies. People with type I diabetes are often initially diagnosed in this state which is called ketoacidosis. (see below).
There are about 3 million people with Type 1 Diabetes in the United States. Because they cannot produce insulin by themselves, they must administer insulin to themselves for the rest of their lives. Because insulin will be broken down by the stomach, insulin has to be administered by injection. The oral agents (pills) which people may read about are not effective for type I diabetes. Before insulin was discovered in 1929 a diagnosis of Type 1 Diabetes was akin to a death sentence. When it was initially discovered, it enabled many people to live longer and more productive lives. As their lifespans increased, doctors, scientists, and patients, all learned about the complications related to this disease. At the present time, people with Diabetes are advised to control their blood sugar to levels as close to normal as possible in order to avoid these complications.
Long-Term Complications of Type I Diabetes
The long-term complications from Diabetes type I can be divided into microvascular complications when it affects the very small arteries and macrovascular disease when diabetes affect the larger arteries. When Diabetes destroys very small blood vessels, microvascular disease, the person with diabetes may face blindness, kidney failure, and neuropathy (a condition in which people experience pain due to nerves providing inappropriate pain signals, as well as experiencing inappropriate numbness, particularly their feet and hands). In fact, Diabetes( both type I and type II) is the most common cause of blindness in the United States and the most common cause of kidney failure and dialysis. Diabetes type I can also affect large blood vessels, a process which physicians refer to as macrovascular disease. This can lead to poor circulation to the feet, impotence in males, heart attacks, and strokes. Impotence can sometimes serve as a warning sign of more serious cardiovascular problems, and can alert physicians to the presence of macrovascular disease. The combination of poor circulation and neuropathy often leads to foot damage, and as a result, people with Diabetes are about 100 times more likely to develop injuries to their feet that lead to amputations than people without diabetes. Because it is an autoimmune disease, these patients and their families are more likely develop other autoimmune diseases such as Sprue hypothyroidism, and Adrenal insufficiency. Some people believe they are also more likely to develop or have a family history of autism but the statistical analysis to prove or disprove this believe has not been completed. There is also evidence that people with diabetes are more likely to develop cognitive impairments (ability to think and reason) similar to those people who have Alzheimer’s disease.
Although diabetes does present grave long-term health problems, advances in technology have made it possible for people with type I diabetes to have a life span comparable to those people without Diabetes. Some people with Type 1 Diabetes live a normal lifespan and they are being evaluated to determine what elements they have in common that enable them to do so well. While statistics apply to a group, individuals can change their lifestyle and embrace the newest technology to lower their chances of developing these complications. While there is no cure for diabetes, if we look back over the last 30 years since I became an endocrinologist, many advances have occurred which have enabled physicians to help their patients improve their control and lower their chances of developing or dying from these complications. In addition to being better able to control blood sugar, we have recognized other risk factors such as abnormal cholesterol and high blood pressure which increase the chance of developing complications In addition to advances in controlling sugar, we have many more medications to help normalize a patient’s lipid panel (the HDL or good cholesterol, the LDL or bad cholesterol, as well as Triglycerides). Scientists have also developed many medications to help normalize blood pressure as well. The worst risk factor is still smoking and we now have medications to help patients quit this destructive habit. In addition, treatment for the secondary complications has also advanced. By utilizing all of these tools, people with Diabetes type I have the potential for a normal life span.
Diabetic Ketoacidosis (DKA)
In addition to the complications mentioned above, people with Type I Diabetes may develop a condition called Ketoacidosis which is caused by an almost complete lack of insulin in the body. In addition to very high sugar levels, the body’s fat will break down, as it becomes the only fuel the body uses. During this process, ketone bodies and fatty acids are released into the blood stream which leads to the blood becoming very acidic—hence the term Diabetic Ketoacidosis or DKA. If this occurs, the patient must be rushed to a hospital for lifesaving treatment. Many patients are initially diagnosed with type I diabetes when they are brought into their local emergency room extremely sick. They are usually quite lethargic, dehydrated, and breathing rapidly and have an accelerated heart rate. The doctor will discover the source of the symptoms by observing a very high sugar, an electrolyte imbalance, the acidosis, and acetone in the urine. DKA is a life-threatening condition and patients with this condition must be immediately treated in a hospital with intravenous fluids, insulin, and electrolyte correction. DKA may also occur when individuals with Type I Diabetes refrain from taking insulin, or develop an infection or another illness which stresses the body. Even though a physician may search for the inciting cause of DKA in an individual with stable type I diabetes, it sometimes occurs without a known cause.
Type II Diabetes – Overview
Diabetes Mellitus Type II is a different disease than Type I Diabetes. Rather than being caused by an inability to produce insulin, people with Type II Diabetes can initially make plenty of insulin, but the insulin does not work properly. To compensate, the beta cells in the pancreas produce excessive amounts of insulin to maintain normal blood sugars. This state of needing double or triple the typical amount of insulin to achieve a normal blood sugar is known as insulin resistance. This process is analogous to a person receiving a cut in their salary. In order to pay bills on time and meet other financial obligations, the person must work over time. As he/she continue to receive pay cuts, the person must keep working more hours to make ends meet. Eventually, the person becomes tired from the stress of working so many extra hours, and eventually he cannot work at all. To an outsider, who only has access to the bank account and the bills, things seemed OK before the person stopped working, because all the bills were paid. When he stops working, the bills will suddenly mount up and the bank balance will nosedive and he may go into debt. In this analogy, the debt is like the blood sugar which stayed normal for a long period of time, and then suddenly starts to rise. In a similar manner, the pancreas has been forced to produce so much more insulin due to the insulin’s inefficiency, and the pancreas eventually fatigues. When the beta cells of the pancreas are no longer able to produce excessive amounts of insulin, the insulin levels start to fall and blood sugar levels rise. At this point Type II Diabetes can be diagnosed.
There are 27 million Americans with Type II Diabetes. While the incidence of diabetes increases with age, and most people are diagnosed during middle age, its occurrence is increasing among teenagers and children. The person will be symptom free until their blood sugars rise to a high level. When the sugar is high enough to spill into the urine, people with Type II Diabetes tend to notice the excessive thirst and urination. They will not become critically ill with ketoacidosis and consequently they may experience these symptoms over a longer period of time than those people with Type I diabetes. People who have one parent with Diabetes Type II have a 50% chance of developing this condition. When both parents have Type II Diabetes, the odds increase to about 95%. Type I and Type II Diabetes are two genetically distinct diseases. If you have parents with one Type, you are more likely to get that Type but the chances of getting the other Type are no different than that of some body without a family history of diabetes. As people gain weight, the chances of developing type II diabetes increases. However, there are many people who are not overweight who develop diabetes type II. It is a combination of genetic endowment acting and environmental factors that will determine if and when a person develops this disease. People with Diabetes type II, are prone to both microvascular and macrovascular complications mentioned in the discussion of type I diabetes.
Insulin resistance is usually present for about ten years before blood sugar levels become abnormal. During this period of time, while the person has Prediabetes, he may unknowingly face significantly increased risk of both microvascular and macrovascular disease similar to that of the person with type I diabetes (see above). While the microvascular complications are associated with visual impairment, kidney disease, the macrovascular complications lead to heart attacks, strokes and non-traumatic amputations. In the general population, insulin resistance increases with age, lack of exercise, and increased body fat. There are 79 million Americans or one third of the US population has Prediabetes and many do not know it. If undiagnosed or if no steps are taken to improve health, prediabetes almost always develops into Type II Diabetes. While people with Prediabetes have normal blood sugars, physicians look for several factors to determine who is most like to either have or develop it. These factors are a positive family history of diabetes type 2, a personal or family history of gestational diabetes or babies that were born very large, a large amount of fat above the belt, high blood pressure, elevated cholesterol, gout, and sleep apnea. Physicians often advise prediabetic patients who are overweight to engage in weight loss activities because weight loss often improves insulin resistance. Prediabetic individuals who adapt to a lifestyle involving regular exercise, healthy diet, and maintaining an appropriate weight can lower the chance of developing Type II Diabetes by 60%. Making these healthy lifestyle choices regularly can even make it possible to achieve normal blood sugars naturally, and medication may not be necessary. However, regaining weight, developing a secondary illness, experiencing severe stress, or using medications that negatively influence insulin levels may push prediabetes into Type II Diabetes. Even though the blood sugars are relatively normal, they may still have the microvascular and macrovascular complications from Diabetes. Sometimes, their predilection toward Diabetes is discovered when they present with a heart attack or stroke. Their ophthalmologist may notice an abnormality in their retina upon a routine eye exam or their blood may become abnormal indicating renal failure. They may even develop a sore on their feet that doesn’t heal and evaluation may reveal poor circulation (peripheral vascular disease) or nerve impairment (peripheral neuropathy). Occasionally a male may develop impotence as the first sign of macrovascular disease. For these 79 million Americans, what they do not know can hurt them. As the percentage of people with obesity increases, the number of people with Diabetes type II and Prediabetes will increase as will the complications of this disease.
Differences between Type I vs. Type II Diabetes
Type I Diabetes is usually diagnosed during the childhood or teenage years when the patient is brought into the emergency room with DKA (see above). Unlike many people with diabetes type II, people with type I are usually not overweight. Their insulin levels are low to nonexistent, rather than high, and their symptoms seem to come on suddenly. Their disease is caused by a destruction of the beta cells rather than by insulin resistance. Oral medications and the new incretin mimetics are not recommended for people with type I diabetes.
Because people with Type I Diabetes do not have any insulin, they have a much more difficult time controlling their blood sugars. It requires more time, effort, and expense to maintain healthy levels of blood sugar. Type I diabetics must check their blood sugar more often, visit their endocrinologist more frequently, count carbohydrate consumption accurately, and self-administer insulin in exact amounts. They must also learn their bodies’ specific reactions to eating, exercising, and insulin administration; this helps them notice the patterns of their high and low blood sugars in order to know what to expect and make treating their condition a little easier. Type I Diabetics must also learn to objectively recognize physiological and emotional symptoms of high and low blood sugars and remind themselves to test their blood sugar and treat it accordingly.
Type II Diabetes and Gestational Diabetes are considered to be separate conditions, but Gestational Diabetes may actually be the first sign of Type II Diabetes manifestation. This is different from diabetes in pregnancy in which a person with diabetes becomes pregnant. With Gestational diabetes, an abnormal blood sugar manifests itself for the first time.
As long as the body can produce sufficient insulin to meet its needs, blood sugars are normal. During pregnancy, the body needs much more insulin, and the increased need for it coupled with a limited capacity to produce that much insulin can lead to the first high sugars the patient will ever experience. It can also be thought of as Prediabetes revealing itself at a time of increased need for insulin production. Gestational Diabetes can cause problems for the baby including premature birth and high birth weight for babies born at the appropriate time. If not properly treated, it can increase the risk of fetal death. Pregnant women need much more insulin. In fact, as the pregnancy proceeds the amount of insulin they need can increase three or four fold. If they cannot meet their high demand for insulin, the sugars will start to rise. About 90% of the time, the sugars revert to normal after the pregnancy.
Because Gestational diabetes places the baby at such a high risk, it must be discovered early and treated very aggressively. Obstetricians routinely check all pregnant women for this condition in the seventh month by giving them sugar and seeing if they are about to get their sugar down to normal. The pregnant woman and her baby have the same blood sugar level. If she consumes carbohydrates but cannot produce enough of her own insulin to get the sugar down to normal, the baby will use its own developing beta cells (in its own pancreas) to produce insulin to treat their shared blood sugar. Her baby’s insulin would help her blood sugar come down, but itbe at risk for complications. Because the baby is so much smaller than she is, it will be exposed to extremely high levels of insulin which may delay lung maturity, increase its size, and increase its risk for death. When women become pregnant, their sugars are normally lower than before and they need much tighter control than that of a woman with diabetes who was not experiencing gestational diabetes. She and her physician should try to keep her sugars as close to that of a normal pregnant woman as possible. They need to learn how to check their sugar, chart it about four times per day, and stick to their diet. If they consume too many carbohydrates the sugar will increase. If they have inadequate amounts of carbohydrate they may develop acetone which can hurt the baby. If while consuming an appropriate amount of acetone, the sugars increase beyond our established goals, insulin is recommended. By taking injectable insulin the baby does not need to over-produce insulin to her mother’s blood sugar, and thereby put itself at serious risk. Ultrasounds are used to follow the baby’s growth. If it grows at a rate that is too fast, even if sugars are normal, insulin would be indicated.
When the pregnancy is completed, the extra insulin resistance dissipates and most women return to the blood sugar levels they had prior to becoming pregnant. All these women should maintain a healthy diet after the baby’s birth, and about 10% of them will develop frank diabetes in which they will require insulin or pills to maintain normal blood sugars for the rest of their lifetime.
Peripheral Vascular Disease
Macrovascular disease which causes strokes and heart attacks by affecting the large arteries that go to the heart and brain respectively, may also affect the arteries that supply blood to the feet. When the circulation to the feet is impaired the condition is called peripheral vascular disease(PVD). Claudication, or experiencing a cramping pain in the leg while walking, may be the first sign of PVD. People with Diabetes are about 30 times more likely to have impaired circulation to their feet. If they get an injury that does not properly heal, the area on the foot may become severely infected, not respond to antibiotics, and leave the person with the choice of accepting non-traumatic amputation or dying. Microvascular disease (small blood vessels) which affects the eyes and kidneys may also affect the nerves to the hands and feet, a condition called diabetic neuropathy. Their feet may become numb, leaving the person with Diabetes vulnerable to injuries from tight fitting shoes. Because they will not feel pain, these injuries may become very severe before the person is aware of their occurrence. The neuropathy and peripheral vascular disease leave the feet very vulnerable. People with Diabetes are taught how to care for their feet to try to prevent this occurrence.
Monitoring Blood Sugar
When I first started practice in 1980, Doctors were just started to monitor blood sugars in the office but the machines were too cumbersome to become popular for everyday use. By the middle 1980s, the ability to obtain a blood sugar with a drop of blood taken from the finger started being used by patients in their homes and by the early 1990s almost every patient with diabetes was encouraged to check their sugars. Patients were able to use these numbers to see the effect different foods had on their sugar and modify their diets. Patient charted their sugars and Doctors would use these charts to adjust oral medication, insulin, or to give advice about exercise. Rather than relying on one blood sugar measurement to guess at control, doctors were able to get a much better idea about control because they could see the blood sugars at different times of day and different days of the week. As computers became more sophisticated, doctors and patients became able to download the results of the monitor into different computer programs to analyze blood sugar trends. Patients who did not stick to their diet would often “forget” to bring in their charts or monitoring devices. Because of the difficulty sticking to a diabetic regimen there would often be tension between the doctor and the endocrinologist
In the late 1980s a hemoglogin a1C test was developed and implemented. This test provides an estimate of blood sugars over a 3 month period. It helped doctors understand how well an individual patient was controlling his sugar. By combining the results of the hemoglobin A1C with glucose monitoring, Doctors were able to understand how well a patient was controlling his sugar and enabled him to improve control. After control could be measured, the correlation between good diabetic control and the complications of Diabetes was finally proven and Doctors and patients were encouraged to get the sugars as close to normal as possible. Patients took much of the responsibility for controlling their disease because they could now see the numbers they were trying to control. When visiting the doctor’s office, they anxiously awaiting the results of their A1C as a student waits for the results of their exams. Some patients have attached so much emotion to their numbers that they see themselves as failures if the numbers are high and are now encouraged to see these numbers as feedback ie opportunities for improvement.
Evolution of Diabetes Treatment
When I first opened my office for endocrinology in the 1980s, patients used to test their urine and chart the results. I had a few types of insulin, one oral agent, and general guidelines about diet. The insulin was matched to an appropriate diet and then the patient had to rigidly stick to it. Diet, which is still the cornerstone of diabetes treatment, is now much more scientific. Because of the advent of long-acting peakless insulin coupled with very short acting insulin which can be used as a bolus, patient who are insulin dependent learn how to count the carbohydrates in a meal and then calculate the appropriate amount of insulin. Insulin injection is much easier now with the new pens that were available. When an inhaled insulin was developed in the late 1990s, the patients actually preferred injections because they were faster, easier, and did not have the risk of causing pulmonary disease. Many patients now have insulin pumps. Some patients are able to monitor their plasma glucose continuously with a continuous glucose monitor.
In the over 30 years I have been in practice, I have also seen the development of new medications which are helpful for Diabetes type 2. While diet and exercise still remain the cornerstone of good diabetes treatment, the number of different classes of medication have increased from one to five. Patients are often on a combination of medications to help them achieve control. In addition to having a medication that stimulated a tired pancreas to release insulin, doctors can now choose drugs to lower blood sugar by a number of other mechanisms. The other mechanisms by which blood sugar can be lowered include decreasing glucose release from the liver, improving insulin sensitivity, slowing down the rate at which ingested glucose is absorbed and decreasing appetite. At the present time, a new drug is being developed which increases release of sugar by the kidneys. Genetic testing may determine who is likely to develop diabetes (different testing for type I and II) and ways to prevent it from developing into frank diabetes. Medications to modify the immune system are being developed in an attempt to provide a possible cure for type I but are still a long way off. Some large institutions have completed pancreas transplants which have enabled some people with type I Diabetes to come off insulin. While people with Diabetes are impatient feeling little progress since the development of insulin in 1929, scientists are developing new treatment and improving on the old treatment. While there is no cure, they need to maintain the best control they can.
Diabetes management is multifaceted. Patients often struggle to maintain healthy blood sugar levels, even with the aid of more advanced technology. Day-to-day activities like eating and exercising cause blood sugar to go up and down, and diabetics must carefully monitor their blood sugar’s activity. If blood sugar levels are too high or too low, serious health consequences occur. High and low blood sugar levels are accompanied by physiological and emotional symptoms, and Diabetics must learn to recognize them and check their sugars when they have symptoms in addition to checking their sugars at scheduled intervals. When blood sugar is low, people with diabetes experience sweating, anxiety, dizziness, hunger, impaired vision, weakness or fatigue, headache, irritability, shaking, and/or fast heartbeat. The technical term for low blood sugar is hypoglycemia, which is often triggered when there is too much insulin in the person’s body. Hypoglycemia often occurs after increased physical activity (sometimes several hours later) or if the individual has not eaten in a while. Seizures may occasionally result if blood sugars reach a dangerously low level. When blood sugar is too high, or when the person has hyperglycemia, the individual will usually experience frequent urination, dry skin, hunger, blurred vision, drowsiness, irritability, and extreme thirst.
Living with Diabetes
People with diabetes have a part time job managing their Diabetes in addition to their full time job, family commitments and other obligations. In addition to having to watch everything they eat, exercise regularly, and monitor their sugars, people with type I diabetes and some people with type II diabetes need to take Insulin injections. All people with Diabetes need to learn to live with the fear of complications from this disease.
The burden of daily management is much greater for a person with type I than type II diabetes. Every single day, a person with Diabetes Type I needs to test his sugar at least several times per day. He may need a snack if his sugar is too low, and he may need to take insulin if his sugar is too high or he knows it is about to become too high: he must decide how much insulin to take by measuring his current blood sugar then factoring in his anticipated food intake. He must constantly keep track of his blood sugar and adjust his diet and activity level accordingly in order to stave off emergency hospital visits and more long-term health problems. He knows he may do everything he was advised to do and because of factors beyond his control still end up in the hospital with uncontrolled blood sugars, DKA, or a complication from Diabetes. Because this disease strikes at a young age, women have to decide if they should assume the risk of pregnancy. Many patients are attached to insulin pumps and they have to make sure they are working. They may be frustrated because they may take the same amount of insulin, eat the same things, and get the same amount of exercise with very different results when they check their sugars. The treatment of diabetes commands so much knowledge and discipline that it becomes overwhelming for both the patient and their families. Other family members and friends without diabetes may find it challenging, even impossible, to understand or appreciate the day-to-day struggle of individuals with Type I Diabetes. Many patients show remarkable courage and resilience when taking control of their condition and find ways to balance diabetes management along with everything else going on in all areas of their “normal” lives.
Diabetes does not only influence a person’s physicality, but it also enters many other aspects of life. For example, family dynamics often change when a child is diagnosed with Type 1 Diabetes. Parents often take strict control over the child’s diabetes management in an attempt to prevent long-term health consequences, and sibling relationships often deteriorate. Normal rebellious activities during adolescence are frequently exacerbated when the young adult has diabetes, and behavioral problems and poor school performance often develop.
Tension may also arise between diabetic patients and their physicians, especially when blood sugars are not well-controlled. The physician cannot always determine whether the inconsistent blood sugars are due to the diabetes itself or to the patient’s lack of effort in managing the condition. Physicians must understand the daunting task of constantly following a structured regimen of diabetes management while performing everyday tasks like going to school or work. In addition, the physician must understand the patients’ reasonable frustration when diabetes prevents them from doing enjoyable activities. For example, exercise or other physical activities like sports can cause blood sugar to fall, making the diabetic individual feel tired and unable to continue the activity he/she had been enjoying. Adolescents need to figure out how to socialize with their friends without appearing weird because of insulin pumps, dietary restrictions, the need to check sugars, as well as the need to avoid alcohol. Physicians must make the effort to understand all the forces that influence their patients’ behaviors in relation to diabetes management, and do all they can to coach their patients into performing the best they can. Physicians have a responsibility to their diabetic patients to help assess quality of life and the patients’ abilities to meet their life goals in addition to managing their diabetes. It is necessary for the doctor to get to know the patient as a unique human being in addition to understanding the disease afflicting the patient. Instead of treating only the disease, the physician must work as a team with the patient to teach him how to treat the diabetes himself.