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ОглавлениеPart II
Types of Diabetes
CHAPTER 3
Type 1 Diabetes
Now, that you’ve brushed up on some of the basics of diabetes and glucose, you’re probably wondering about your specific type of diabetes. In this chapter, you’ll find out all about type 1 diabetes.
Type 1 diabetes used to be called juvenile diabetes. Half of all people with type 1 diabetes are diagnosed during childhood or their early teen years.
As you know, being diagnosed with diabetes can be a scary—no matter how old you are when you find out. However, being diagnosed with type 1 diabetes as a child can be downright terrifying. For example, it might have come on so fast that you went into a coma before anyone suspected diabetes. After asthma, type 1 diabetes is the second most common chronic disease in children.
Keep in mind, type 1 diabetes can occur at any age. About 5% of adults with diabetes have type 1 diabetes.
Early Symptoms and Tests
People with type 1 diabetes make very little or no insulin, which means that the symptoms of diabetes are often serious and swift. Without insulin, the cells in your body can’t do their essential work. Most people with type 1 diabetes will feel quite sick and may even be rushed to the hospital due to high blood glucose.
Common Symptoms of Type 1 Diabetes
• Frequent urination as the body tries to flush out excess glucose in the blood
• Extreme thirst due to dehydration
• Fatigue because the necessary glucose is not getting to your cells
• Blurred vision because of a buildup of fluid in your eyes or elevated glucose levels
• Weight loss, even with increased appetite
• Nausea and vomiting
A Different Type 1 Diabetes
Some people with type 1 diabetes may have a slow and relentless progression of symptoms. In fact, they may not need to start insulin right away. This condition is called latent autoimmune diabetes of the adult (LADA). As its name suggests, it occurs in adults. Scientists are still trying to clearly define the disorder to improve diagnosis and treatment of people with LADA.
Tests for Type 1 Diabetes
If your doctor suspects diabetes, he or she will perform a blood test, such as the A1C, fasting plasma glucose test, or the random plasma glucose test. These tests are discussed in more detail in chapter 2. If a fasting plasma glucose test is 126 mg/dl or higher or the random plasma glucose test is 200 mg/dl or higher, you may be diagnosed with diabetes.
Your own description of the way your diabetes symptoms developed will help your health care provider classify your diabetes as type 1.
Your health care provider may also take a urine sample to check for the presence of ketones. Ketones are byproducts produced by the body when it breaks down fat for energy. The presence of ketones could be a clue that you have type 1 diabetes. However, keep in mind that ketones are also common in people with type 2 diabetes who are under stress or who have a medical emergency.
In addition, once diabetes has been diagnosed, your health care provider may take a blood sample to test for the presence of autoantibodies in your blood (see more about autoantibodies in the next section). The presence of autoantibodies could mean you have type 1 diabetes. However, some people with type 1 diabetes do not have autoantibodies.
Another measurement, called the “C-peptide” test, measures the amount of insulin produced by the body. It may be ordered if you’ve just been diagnosed with diabetes and is sometimes ordered in conjunction with a diagnosis of type 1 diabetes.
Causes and Risk Factors
Scientists do not know the exact cause of type 1 diabetes. They suspect that it is a combination of factors due to a person’s genetics and environment.
However, scientists do know that in people with type 1 diabetes, their immune system mistakenly destroys the insulin-producing cells of their pancreas. The destruction can happen over months and years. The body treats these insulin-producing cells as foreign invaders (not good!). This is called an autoimmune response.
Autoantibodies
In fact, the body creates specific proteins called autoantibodies. When certain autoantibodies are present, they indicate an autoimmune response is helping to kill cells in the pancreas.
Four antibodies are particularly common in people with type 1 diabetes: islet cell autoantibodies, insulin autoantibodies, glutamic acid decarboxylase autoantibodies, and tyrosine phosphatase autoantibodies. Doctors often test for the presence of these autoantibodies to determine whether someone has type 1 diabetes.
Autoimmune responses can occur in other diseases, such as multiple sclerosis and lupus. In fact, people with other autoimmune disease, such as thyroid disease and celiac disease, are more likely to have type 1 diabetes.
Scientists do not know what causes autoimmune diseases. However, in diabetes, researchers have found a few triggers that may point to why the body starts attacking itself.
Celiac Disease
One in 20 people with type 1 diabetes has celiac disease.
Genes and Family History
Scientists have long suspected that family history and genes play a role in type 1 diabetes. For example, if your parent or sibling has diabetes, you are more likely to develop the disease than someone without a family history.
The way in which genes interact to cause diabetes is an extremely complex process that scientists are only just beginning to unravel. Some of the most promising discoveries have been made with a group of genes called HLA that are involved in the body’s immune response. Scientists can test a person’s DNA for specific mutations in HLA genes that would indicate that that person might get type 1 diabetes.
Race and Ethnicity
In addition to family history, race and ethnicity appear to play a role in who develops type 1 diabetes. White people are much more likely to develop type 1 diabetes than other racial groups. For example, 1 in 100,000 people in Shanghai, China, has type 1 diabetes, but more than 35 in 100,000 people in Finland have type 1 diabetes. Most likely, certain racial groups pass down genes that either trigger or protect against type 1 diabetes.
Viruses
Many scientists suspect that viruses may cause type 1 diabetes. Some people who develop diabetes have often had a recent viral infection. Also, cases of diabetes have frequently occurred after viral epidemics. Viruses—such as those that cause mumps, German measles, and a virus related to the one that causes polio—may play some role in causing type 1 diabetes. Nonetheless, there is no virus known that specifically triggers type 1 diabetes.
Chemicals and Drugs
Several chemicals, in rare cases, have been shown to trigger diabetes. Pyriminil, a poison used to kill rats, can trigger type 1 diabetes. Two prescription drugs, pentamidine (used to treat pneumonia) and L-asparaginase (an anticancer drug) can also cause type 1 diabetes.
Prevention
There is no way to prevent type 1 diabetes. However, scientists are deeply interested in finding ways to delay or reduce the severity of type 1 diabetes.
People without outward symptoms of type 1 diabetes often produce autoantibodies that can be detected in the blood. The autoantibodies may be present several years before diabetes is diagnosed. Currently, scientists can screen people who may be at high risk because they have a family member with type 1 diabetes or because they carry mutations in certain HLA genes.
For example, if you have a parent or sibling with type 1 diabetes, you are 10% more likely to get diabetes. However, if you also carry certain HLA genes or autoantibodies in your blood, you are even more likely to get type 1 diabetes.
Several studies currently underway are testing whether treating these people early may improve their lives. One study is treating people with insulin in a pill form, and other studies are examining whether certain diets could affect the development of type 1 diabetes. Still other studies are aimed at vaccines to slow the progression of diabetes after diagnosis.
In summary, it is unlikely that either genetics or environment alone causes diabetes. Instead, it is probably a complicated interplay between the genes you were born with and the world in which you live.
Management and Treatments
How you manage your diabetes depends on your personal goals and needs. No two people with diabetes are exactly alike. Therefore, everyone with diabetes needs an individualized diabetes care plan.
Common Goals for People with Diabetes
• Prevent short-term problems, such as a glucose level that is too low or too high.
• Prevent or delay long-term health problems, such as heart disease and damage to the nerves, kidneys, and eyes.
• Maintain a healthy lifestyle and keep doing enjoyable activities, such as exercising, working, and socializing.
Work with your health care providers to come up with a plan for managing your diabetes and meeting your goals. You’ll find more about this topic in chapter 9. For now, though, let’s talk about some of the treatments for managing type 1 diabetes.
• People with type 1 diabetes must take insulin. Therefore insulin injections play a big role in your diabetes care plan. How much insulin you need to take depends on your blood glucose level or what you predict the level will be after a meal.
• Naturally, certain food choices also play an important role in your diabetes management plan, because they can add glucose to your blood.
• Usually, exercise can lower your blood glucose level and, in turn, decrease your dose of insulin. So, you’ll need to account for exercise and physical activity in your diabetes management.
Insulin
Most people with type 1 diabetes take insulin by injecting it with a needle and syringe or an insulin pen. The goal is to mimic normal insulin release as closely as possible.
People without diabetes have a low level of insulin available in the blood most of the time. This is a background, or basal, level of insulin. After meals, a bolus (extra dose) of insulin is released, just enough to clear the glucose in the blood after eating.
To imitate this sequence, you can develop a regular schedule of insulin injections using different forms of insulin. Read on in chapter 13 for a lot more about insulin and insulin plans. Other people use insulin pumps to dispense insulin at a steady background, or basal, rate and to provide extra insulin to cover meals. More about insulin pumps can be found in chapter 13.
Although today’s insulin pumps are worn externally, researchers are developing and testing pumps that are placed inside the body. Ideally, the pump would sense the amount of glucose in the blood and deliver the right amount of insulin, as needed. These pumps are called closed-loop systems.
Your type of insulin therapy should relate directly to your health and your lifestyle choices. Your chosen therapy may aim to keep your blood glucose levels from shooting too high after meals or falling too low between meals. Or your therapy may aim to keep after-meal blood glucose levels as close as possible to those of someone without diabetes.
The food you eat and the exercise you get go hand in hand with your insulin therapy. Of course, healthy eating and regular exercise are a part of everyone’s healthy living plan. But for you, knowing how these two daily features move your blood glucose level up and down is essential.
To know how much insulin you’ll need to have, it helps to know:
• Your current blood glucose level (you know this by blood glucose testing).
• What you plan to eat (so you can estimate how much your blood glucose will increase).
• What physical activities you plan to do.
There is more information about insulin therapy and different insulin plans in chapter 13, and more about healthy eating in chapter 10. Read about physical activity and exercise for people with type 1 diabetes in chapter 11.
Pancreas Transplants
So far, the only way to treat type 1 diabetes is to give the body another source of insulin. Usually, this is done through insulin injections. However, new experimental approaches also show some promise.
Some patients with type 1 diabetes have experienced positive results from pancreas transplants. Typically, part or all of a new pancreas is surgically implanted. The old pancreas is left alone; it still makes digestive enzymes, even though it doesn’t make insulin. Most organs are obtained from someone who has died but decided to be an organ donor.
A transplant of the pancreas is usually reserved for those with serious complications. Pancreas transplants are most often done when a patient also receives a new kidney. The pancreas transplant adds little further risk and offers big benefits. However, transplant surgery is risky. Each person needs to carefully weigh the potential benefits and risks.
Benefits of Pancreas Transplants
• You may be able to maintain a normal blood glucose level without taking insulin.
• Many of the diabetes-related side effects are prevented or delayed.
• Most people with nerve damage who receive a pancreas transplant do not get worse and sometimes show improvement.
Downsides to Pancreas Transplants
• The body treats the new pancreas as foreign and the immune system attacks the transplanted pancreas.
• Transplant patients must take powerful immunosuppressant drugs to prevent rejection of the new pancreas. Drugs that suppress the immune system can lower resistance to other diseases, such as cancer, and to bacterial and viral infections.
Islet Transplants
Researchers are testing transplanting only the islet cells of the pancreas. These are the cells in the pancreas that secrete insulin. The islets also sense glucose levels in the blood and dispense the right amount of insulin to the blood.
Islets from a deceased person are taken out, purified, and then transferred to a person with type 1 diabetes. These cells then go on to make insulin.
The procedure has been beneficial for some people—allowing them to take less or sometimes no insulin. However, islet transplantation is still considered experimental.
Organ Donors
One of the biggest problems with both pancreas and islet cell transplantation is the shortage of organ donors. About 7,000 bodies are donated for organ transplants each year in the United States—too few to supply islet cells for everyone with type 1 diabetes.
CHAPTER 4
Type 2 Diabetes
Most people (about 95%) with diabetes have type 2 diabetes. Type 2 diabetes tends to develop in people over 40 and used to be called adult-onset diabetes. If you’re reading this chapter, you or someone you love has probably been diagnosed with type 2 diabetes.
However, in recent years, more children and teens are developing type 2 diabetes. Much of this has to do with kids becoming obese and inactive.
Early Symptoms and Tests
Usually, type 2 diabetes does not appear suddenly. Instead, you may have no noticeable symptoms or only mild symptoms for years before diabetes is detected, perhaps during a routine exam or blood test.
Common Symptoms of Type 2 Diabetes
• Frequent urination due to the body trying to flush out excess glucose
• Increased thirst due to dehydration
• Fatigue because the necessary glucose is not getting to your cells
• Blurred vision due to a buildup of fluid in your eyes or elevated glucose levels
• More frequent or slower-healing infections
Tests for Type 2 Diabetes
If your doctor suspects diabetes, he or she will perform a blood test, such as the A1C, fasting plasma glucose test, or the random plasma glucose test, as discussed in chapter 2. If your A1C is 6.5% or higher, your fasting plasma glucose test is 126 mg/dl or higher, or your random plasma glucose test is 200 mg/dl or higher, you will be diagnosed with diabetes. Usually, a second test will be done to confirm the diagnosis.
Causes and Risk Factors
Initially, people with type 2 diabetes will usually make insulin for some time, unlike people with type 1 diabetes, who stop making insulin once their diabetes fully develops. However, sometimes people with type 2 diabetes do not respond properly to insulin (this is called insulin resistance), or their body doesn’t produce enough insulin, or both. These problems lead to the same outcome: insulin cannot deliver glucose to the cells that need it and glucose builds up in the blood.
Many cells in the body contain special proteins called receptors that bind to insulin. They work like a lock and key. In order for glucose to enter a cell, insulin (the key) must first fit into the insulin receptor (the lock). In addition to working as a key in a lock, insulin performs other important jobs. It inhibits the release of glucose and other substances from the liver and helps make proteins in the body. So, problems with insulin production or resistance can also make the liver release too much glucose.
Diabetes is a progressive disease. Initially, the pancreas produces enough insulin to overcome these problems. But over the course of several years, the pancreas no longer makes enough insulin or releases it too slowly. Without enough insulin to meet the body’s needs, glucose levels rise and diabetes develops.
Scientists do not know why the pancreas stops working in people with type 2 diabetes. Some believe that the system that tells the pancreas to make more insulin is broken. Others think that the pancreas—after many years of working overtime to overcome insulin resistance—simply burns out.
Genes and Family History
Genes and family history appear to play a strong role in the development of type 2 diabetes—an even stronger role than in type 1 diabetes. For example, if a person with type 1 diabetes has an identical twin, there is a 25–50% chance that the twin will develop diabetes. But if a person with type 2 diabetes has an identical twin, there is a 60–75% chance that the twin will develop diabetes.
The way in which genes interact to cause diabetes is an extremely complex process that scientists are only just beginning to understand. There is no known “type 2 diabetes gene.” And it is likely that a large number of genes interact to cause type 2 diabetes. Some of the most promising studies have been done since scientists decoded the DNA of the human genome.
With the sequence of the human genome in hand, scientists have been able to link mutations in certain genes to type 2 diabetes. It appears that people pass these mutations down to family members through their DNA.
Race and Ethnicity
More evidence for the role of genes in type 2 diabetes comes from studying certain ethnic groups. African Americans, Asian Americans, Hispanics (except Cuban Americans), and Native Americans all get type 2 diabetes more than whites.
Incidence of Diabetes by Ethnicity
• 7.1% of non-Hispanic whites have diabetes
• 8.4% of Asian Americans have diabetes
• 11.8% of Hispanics have diabetes
• 12.6% of African Americans have diabetes
• 16.1% of Native Americans have diabetes
According to the “National Diabetes Fact Sheet, 2011,” from the Centers for Disease Control and Prevention.
The unusually high rate of diabetes in Native Americans also holds true for their children. Unfortunately, 4.5 out of 1,000 Native American children have diabetes, with rates as high as 50 out of every 1,000 children in the Pima Indian tribe in Arizona.
Obesity
Type 2 diabetes tends to develop in people who have extra body fat. Three-fourths of all people with type 2 diabetes are or have been obese. Body mass index measures your body’s amount of fat based on your height and weight. A body mass index of 30 or above is considered obese.
Scientists also think that some people may have genes that put them at a higher risk for obesity—and thus diabetes.
In some way, having too much body fat promotes resistance to insulin. This is why, for so many years, type 2 diabetes has been treated with changes to food and physical activity. Losing weight and increasing muscle while decreasing fat helps your body use insulin better.
Body Shape and Obesity
Your body shape may help determine your risk of developing type 2 diabetes. Extra fat above the hips (central body obesity or having a body shaped like an apple) is riskier than having extra fat in the hips and thighs (having a body shaped like a pear). Central body obesity, as well as overall obesity, is more common in African Americans than whites, which helps explain why diabetes is more common in African Americans.
Sweet Tooth
You can’t get diabetes from eating too much sugar. However, eating too much sugar isn’t good for anyone. Sweets contain lots of carbohydrates and calories, which can lead to excess pounds. Eating too much of anything (including sweets) can lead to obesity—and diabetes.
Age and Lifestyle
Age is also a risk factor for type 2 diabetes. Half of all new cases of type 2 diabetes occur in people over 55 years of age. People also tend to gain weight as they get older, so perhaps diabetes occurs more often in older people as they put on extra pounds.
Leading an inactive, sedentary lifestyle can also lead to obesity and diabetes. You’ll find out more about getting and staying in shape with your diabetes in chapter 11.
Prevention
It may sound like a no-brainer, but the best way to prevent type 2 diabetes is to be fit and to maintain a healthy weight. Okay, that’s a lot easier said than done. However, knowing it can be done is encouraging!
Studies show that people at high risk for diabetes may be able to prevent diabetes with weight loss, healthy eating, and exercise.
One of the most famous studies that looked at the prevention of type 2 diabetes is called the Diabetes Prevention Program or DPP. Scientists studied whether changing lifestyle habits, such as choosing healthier foods and physical activity, or taking diabetes medication could delay or prevent type 2 diabetes in people at high risk for the disease. The study ended a year early, when scientists discovered some amazing results!
DPP Study Results
• People who lost about 7% of their body weight through eating well and increasing their physical activity (30 minutes a day five times a week) had a 58% lower incidence of diabetes than people who took a placebo (dummy pill).
• People in the study who took the diabetes medication metformin had 31% lower incidence of diabetes than people who took a placebo.
Management and Treatment
With all the talk about the importance of eating well and exercising, you’re probably guessing that these two areas play a big role in managing your diabetes. Yes, living a healthy lifestyle is one of the most important things that you can do for yourself and your diabetes. If needed, there are additional options for managing your diabetes, including diabetes pills and insulin. Pancreas or islet transplantation is not usually an option in type 2 diabetes.
Common Goals for Living with Diabetes
• Prevent short-term problems, such as too low or too high glucose.
• Prevent or delay long-term health problems, such as heart disease and damage to nerves, kidneys, and eyes.
• Maintain a healthy lifestyle and keep doing things you enjoy, like exercising, working, and socializing.
How you manage your diabetes depends on your personal goals and needs. There are a number of different options for treating type 2 diabetes. Work with your health care providers to come up with a plan for managing your diabetes and meeting your goals (you’ll find more about this topic in chapter 9).
For now, though, let’s talk about some of the basics in managing type 2 diabetes.
Tips on Managing Type 2 Diabetes
• Not everyone with type 2 diabetes needs pills or insulin when they are diagnosed.
• Some people who are newly diagnosed can begin with new meal and physical activity plans. For many, eating healthy food portions and exercising regularly keep blood glucose levels near normal.
• Your treatment plan is based on your usual blood glucose levels. Ideally, you will want to keep your blood glucose levels as close to normal as possible.
• For most people, the goal is to keep blood glucose levels between 70 and 130 mg/dl before meals and less than 180 mg/dl after meals. Your doctor may have different goals for you.
Food and Physical Activity
For many, treatment for type 2 diabetes means a balance of healthy eating and exercise. Most people with type 2 diabetes are advised to lose weight and improve their physical fitness, which can decrease weight and resistance to insulin. The severity of type 2 diabetes can be greatly reduced by maintaining a healthy body weight.
Losing a Few Pounds
Even a modest weight loss of 10–15 pounds can have benefits for your health and diabetes.
Benefits of Physical Activity and Healthy Eating
• Physical activity, such as exercise, helps by taking some glucose from the blood and using it for energy during a workout, an effect that lasts well beyond the workout.
• As your physical fitness improves with regular exercise and activity, so does your body’s sensitivity to insulin.
• Healthy eating keeps glucose levels lower.
You’ll find out more about healthy eating, physical activity, and exercise in chapters 10 and 11.
Medication for Diabetes
In addition to healthy eating and exercise, some people use pills to help manage their diabetes. These pills are called “oral diabetes medications” or “diabetes pills” because you take them by mouth instead of injecting them like insulin. In addition to pills, people with type 2 diabetes now have the option of taking injectable medications to lower their blood glucose.
If needed, you and your health care provider will work together to find the best medication for your goals and lifestyle. Only your health care provider can prescribe these medications. You’ll find out more about these medications in chapter 12.
Tips on Medication for Type 2 Diabetes
• Generally, diabetes pills are only prescribed for people with type 2 diabetes.
• At the time of diagnosis, your health care provider may prescribe a diabetes medication, as well as changes to meals and physical activity.
• Not everyone with type 2 diabetes will be helped by diabetes pills. They are more effective in people who have had high blood glucose levels for less than 10 years.
• They are more effective in people who eat healthy and who produce some insulin.
Insulin
Insulin used to be considered the last resort for people with type 2 diabetes. Now, we know that starting insulin early can help keep you healthier longer.
For example, in the beginning (before you were even diagnosed) your body was becoming more and more resistant to insulin as your blood glucose levels remained high. Then, once you were diagnosed, and perhaps treated with diet and exercise or diabetes pills, your body became less resistant to insulin. Your meal plan or exercise, alone, may have been enough to keep your blood glucose levels under control.
However, for many people, the body becomes more resistant to insulin over time. In fact, you are more likely to use insulin the longer you’ve had diabetes.
It’s Not Failure
It is a big step, but taking insulin does not mean that you have failed to take care of yourself or that your diabetes is worse. It simply means that your body needs more help to keep your blood glucose levels on track.
Insulin Is Common for Type 2 Diabetes
Around 30–40% of people with type 2 diabetes use insulin. If you take insulin, it doesn’t mean your diabetes has changed from type 2 to type 1. You don’t necessarily have type 1 diabetes just because you need insulin. Instead, you are one of many people with type 2 diabetes who uses insulin because it is a helpful treatment option.
Tips for Getting Started
• Find a health care provider who can help you with insulin instructions, injection techniques, and schedules.
• Taking insulin can be intimidating. Find someone you can talk to about getting started. Often people say they wished they’d started taking insulin sooner because it gave them more energy.
You’ll find more information about insulin and insulin plans in chapter 13. There are several different ways to begin taking insulin. You’ll work with your health care provider to develop an insulin plan that is best for you.
CHAPTER 5
Gestational Diabetes
Pregnancy is a time of possibility and excitement. You try to eat well and rest as much as possible. You may celebrate the baby’s anticipated arrival by decorating a nursery or purchasing new baby clothes. You imagine what kind of mother you’ll be to your son or daughter. The last thing you’ve probably been thinking about is getting diabetes. However, finding out you have gestational diabetes raises a lot of important questions. How will it affect you? How will it affect the baby? Will you have diabetes forever?
This chapter will attempt to answer some of these initial questions. Women who manage their diabetes well during pregnancy can have healthy, normal babies. But it takes effort and planning. Work closely with your health care providers to come up with a strategy for managing your diabetes to keep you and the baby healthy during pregnancy.
Gestational diabetes is the technical term for diabetes that develops during pregnancy. It only refers to women who have never had diabetes before and develop high blood glucose during pregnancy. It does not refer to women with preexisting type 1 or type 2 diabetes who become pregnant. Roughly 18% of pregnancies are affected by gestational diabetes, which means about 700,000 American women develop gestational diabetes each year.
Early Symptoms and Tests
Gestational diabetes usually appears around the 24th week of pregnancy. This is when the hormones of pregnancy naturally begin to cause changes in how your body uses insulin (see more about hormones below). Women with gestational diabetes usually don’t experience any outward symptoms of the disorder. A test is the only way to diagnose gestational diabetes.
Most women, except those at very low risk for gestational diabetes, will be tested between 24 and 28 weeks of pregnancy. Your health care provider will give you an oral glucose tolerance test to diagnose diabetes.
Some women who are at very high risk for gestational diabetes may be tested during their first prenatal visit. This might include women who are severely obese, have a prior history of gestational diabetes, have polycystic ovarian syndrome or glycosuria, have previously delivered a very large infant, or who have a strong family history of type 2 diabetes. In fact, your health care provider may diagnose you with type 2 diabetes, rather than gestational diabetes, at this point.
Causes and Risk Factors
Scientists do not know the exact cause of gestational diabetes. However, they have a few clues about how it happens and who is at risk.
Hormones
You’ve probably heard a lot about hormones since becoming pregnant. They are a big part of the changes that occur to help your baby grow. Hormones are chemicals that help the body carry out various functions, like building organs and repairing tissues.
During pregnancy, your body produces lots of hormones in an organ called the placenta. The placenta is also the organ that nourishes the growing baby. These extra hormones are important for the baby’s growth. However, some of these hormones also block insulin’s action in the mother’s body, causing resistance to insulin. All pregnant women—with or without gestational diabetes—have some degree of insulin resistance.
To compensate for all this “resistance,” pregnant women make up to three times more insulin than normal. In some cases, a woman’s body cannot make enough insulin to keep up. Scientists think this occurs in gestational diabetes.
Without enough insulin, your body cannot convert glucose into energy and the excess glucose builds up in the blood. Women with gestational diabetes have elevated blood glucose, much like people with type 2 diabetes.
Genes and Family History
Family history plays a role in gestational diabetes: women with a parent or sibling with diabetes are more likely to have gestational diabetes. Scientists suspect that gestational diabetes is more like type 2 than type 1 diabetes. For this reason, they think that similar genes are involved in both gestational and type 2 diabetes. However, there have been very few studies on the genes specifically involved in gestational diabetes, and there is no genetic test to detect gestational diabetes.
Race and Ethnicity
Women who are Hispanic, American Indian, Asian, or African American are more likely to have gestational diabetes than non-Hispanic white women.
Obesity and Age
Just like type 2 diabetes, obesity and age are risk factors for developing gestational diabetes. Women who are 25 years or older or overweight are more likely to have the disorder. Obesity contributes to insulin resistance and negatively affects the body’s ability to use insulin properly. As discussed above, pregnant women already experience some insulin resistance, so any added resistance through excess weight can put you at higher risk for diabetes.
Prevention and Precautions
The best way to prevent gestational diabetes is to eat nutritious foods, be physically active, and maintain a healthy weight. The goal is to get your body in optimum physical shape before you get pregnant. This may include discussions with your doctor about your weight and wellness before you become pregnant.
Risks for Mom and Baby
Most women with gestational diabetes who manage their glucose levels have healthy babies. However, if you do not actively manage your diabetes during pregnancy, there are significant risks to you and the baby.
Babies born to women with gestational diabetes have a higher risk of jaundice and low blood glucose when they are born. In addition, they are at risk for being born larger than normal. This is called macrosomia. During the last half of pregnancy, the baby grows rapidly. A mother’s high blood glucose during the latter half of pregnancy can lead to a larger-than-normal baby. In some cases, the baby can become too large to be delivered vaginally.
Because women with gestational diabetes tend to have larger babies, they also tend to have more cesarean deliveries. A cesarean section (where a baby is delivered surgically) can be a safer option than vaginal delivery when the baby is larger than normal. The baby may also need to be delivered earlier than the due date. Cesarean deliveries, though relatively safe and frequent, put women at higher risk for infections, increased bleeding, prolonged recovery, and other issues.
Also, the baby may need to be delivered early if he or she grows too large too fast. An early delivery puts the baby at higher risk for respiratory distress because the lungs may not be fully matured.
Women with gestational diabetes are also at higher risk for preeclampsia, a condition in pregnancy in which blood pressure is too high. Swelling of legs and arms commonly goes along with this condition. Preeclampsia can be dangerous for the mother and baby and can mean bed rest for the mother until delivery.
In addition, gestational diabetes puts women at higher risk for urinary tract infections and ketones in their urine. Ketones are byproducts produced by the body when it breaks down fat for energy. They can be harmful to the mom and baby, and the best way to prevent them is to keep blood glucose levels on target. Your doctor may ask you to monitor your ketones (see more about ketone testing in chapter 7).
Management and Treatments
Overall, gestational diabetes is treated much like type 2 diabetes. Most women start with meal planning and regular physical activity to try to lower blood glucose levels. If these strategies do not work, your doctor may prescribe insulin.
Treatment for gestational diabetes is based on the results of your oral glucose tolerance test. In some cases, your doctor may recommend changes in your meal plan or physical activity. In other cases, your doctor may recommend that you start taking insulin right away in addition to changes in your meal plan and physical activity.
Blood glucose goals are narrower for pregnant women than for most people with type 2 diabetes. This is due to the harmful effects that high blood glucose can have on a mother and her growing baby. Work with your health care provider to develop individualized goals for your blood glucose before and after meals.
You will probably need to monitor your blood glucose frequently, perhaps four or more times a day. You can read all about glucose monitoring in chapters 6 and 7.
Just like in type 2 diabetes, women with gestational diabetes have a buildup of glucose in the blood because they do not produce enough insulin.
Food and Exercise
Your meal plan during pregnancy is not designed for weight loss. Instead, the goal is to eat the right food at the right time and in the right amount to manage your blood glucose and promote the healthy development of your baby. Food choices play a key role in managing gestational diabetes because of the importance of controlling blood glucose after meals. It’s important that you meet with a registered dietitian. You may set a daily calorie goal based on the amount of weight you should gain during the pregnancy. The dietitian may also help you adjust your carbohydrate intake to help manage your blood glucose levels. For many women, this is enough to keep blood glucose levels within the target range.
Using moderate exercise to lower blood glucose levels can also help. Most women can swim or walk to keep active. You may also focus on limiting the amount of weight you gain, especially if you were obese before pregnancy. Read more about healthy eating and exercise during pregnancy in chapters 10 and 11, respectively.
Lows in Pregnancy
Luckily, dangerous low blood glucose episodes are relatively rare because insulin resistance is so high late in pregnancy. However, if you seem prone to low blood glucose, remember that the safest time to exercise is after meals, when you are less likely to experience lows.
Insulin
You may need insulin to help you reach your blood glucose goals during pregnancy. It’s extremely important to keep glucose levels as close to normal as possible to prevent any complications. Your health care provider will help you decide whether you need to start insulin and, if so, what kind of plan you’ll follow.
You’ll become more insulin resistant during the third trimester of pregnancy. Therefore, you may need more insulin. This might require a mixture of different types of insulin such as rapid- and intermediate-acting insulin. Look for more information on insulin and insulin plans in chapter 13.
Don’t be alarmed if your total insulin dose increases as your pregnancy continues. This does not mean that your diabetes is getting worse, only that your insulin resistance is increasing, which is to be expected. You may need to make changes in your insulin dosage every 10 days or more often.
Future Considerations
After pregnancy, gestational diabetes goes away in most women. Only 5–10% of women have diabetes after giving birth (usually type 2 diabetes). However, your overall risk for developing diabetes in your lifetime goes up dramatically after having gestational diabetes. From 35% to 60% of women with gestational diabetes eventually develop type 2 diabetes.
You should be tested for diabetes 6 weeks after your baby is born. At this visit, you and your health care provider can discuss goals for maintaining a healthy weight and preventing type 2 diabetes. You can prevent diabetes by taking active steps to get in shape and lose weight after pregnancy. You should then be tested for diabetes at least every 3 years thereafter. If you continue to have diabetes after you deliver, you will be referred to a diabetes care provider.
If you had gestational diabetes, your child is also at risk for becoming obese and developing type 2 diabetes. Breast-feeding your baby is one way to protect your child from developing diabetes. Some studies have shown that breast-feeding can reduce the risk of diabetes in children. It will also help you burn extra calories (and perhaps lose weight) and ensure that your baby is getting the proper amount of nutrition.
In the future, remind all of your providers that you had gestational diabetes. Some drugs, such as steroids, can raise your blood glucose levels, just as pregnancy did. Ask to have your glucose levels tested earlier if you become pregnant again.
The message to take home is that both you and your baby have a lifetime risk of developing diabetes. It is important for the whole family to eat well, be active, and maintain healthy weights.
Tips from the National Diabetes Education Program: “It’s Never Too Early to Prevent Diabetes”
A Lifetime of Small Steps for a Healthy Family
For You:
• Tell any future health care providers about your gestational diabetes.
• Get tested for diabetes 6–12 weeks after your baby is born, then at least every 3 years.
• Breast-feed your baby. It may lower your child’s risk for type 2 diabetes.
• Talk to your doctor if you plan to become pregnant again in the future.
• Try to reach your pre-pregnancy weight 6–12 months after your baby is born. Then, if you still weigh too much, work to lose at least 5–7% (10–14 pounds if you weigh 200 pounds) of your body weight slowly over time and keep it off.
• Choose healthy foods, such as fruits and vegetables, fish, lean meats, dry beans and peas, whole grains, and low-fat or nonfat milk and cheese. Drink water.
• Eat smaller portions of healthy foods to help you reach and stay at a healthy weight.
For the Whole Family:
• Ask your child’s doctor for an eating plan to help your child grow properly and stay at a healthy weight. Tell your child’s doctor that you had gestational diabetes. Tell your child about his or her risk for diabetes.
• Help your children make healthy food choices and help them be active at least 60 minutes a day.
• Follow a healthy lifestyle together as a family. Help family members stay at a healthy weight by making healthy food choices and moving around more.
• Limit TV, video game, and computer game time to an hour or two a day.
