Islets of Hope information for persons with diabetes
Article data compiled by Lahle Wolfe, chart by Lahle Wolfe
Want to Know More About How Genes Play A Role in Diabetes?
To learn more about the genetics of all forms of diabetes read the National Institutes of Health’s online book “The Genetic Landscape of Diabetes.” This book, written both for professionals and laypersons, provides an overview of the genetics of type 1 and type 2 diabetes, as well other less common forms of diabetes.
Q: What type of doctor diagnoses and treats diabetes?
A: An endocronologist, diabetologist, or other physician specializing in endocrine disorders.
Anne Peters, MD
Authoritative and reassuring, Conquering Diabetes will arm readers and their physicians with the latest findings on the diabetes epidemic, helping them to confront the disease effectively and exponentially increase their quality of life. For both Type 1 and Type 2 information.
According to the Juvenile Diabetes Research Foundation (JDRF) there are approximately 18.2 million people with diabetes. Someone is diagnosed every 30 seconds and someone dies from diabetes related complications every 3 minutes.
UPDATE: According to the American Diabetes Association, as of 10/06/2006 this statistic has been change: Someone is newly diagnosed with diabetes every 21 seconds!
Geil, et. al.
main "Diabetes Information" page
Diabetes onset: A combination of genes & environmental Influences
Dr. Gavin, MD, PhD
also, see Diabetes Genetic Research
What is Diabetes?
The two basic types of diabetes most people have heard of are Type 1 and Type 2. There are actually more than two types of diabetes and the cause of diabetes varies. Primary diabetes is when someone becomes diabetic unrelated to the onset of another disease. Secondary diabetes can occur as a result of damage or disease to the pancreas from another disease such as hemochromatosis (iron overload) or cystic fibrosis (CF). If the pancreas is damaged from disease, an injury or surgically removed and can no longer produce insulin a person will develop secondary type 1 diabetes.
Type 1 diabetes occurs when the insulin producing beta islets cells in the pancreas are destroyed. The person will become insulin dependent, meaning they will require daily injections of insulin for life. Inhaled insulin may someday be available, but for now, people with type 1 must take shots or use an insulin pump to administer insulin.
Type 2 diabetes is diagnosed when the body becomes resistant to insulin produced, causing the pancreas to over produce insulin, or, when the body cannot make enough insulin to keep up with demand. Persons with type 2 may or may not have abnormal blood sugars (those that are insulin resistant my test in normal blood sugar ranges but are hyperinsulinemic -- they over produce insulin). It is important to understand the difference between the two basic types of diabetes, the criteria involved in diagnosis, treatment options, and never to self-diagnosed. Anyone with diabetes requires care and direction of a team of diabetes health professionals.
Other types of diabetes include gestational diabetes, maturity onset of diabetes in the young (MODY), latent autoimmune diabetes in adults (LADA) which is sometimes referred to as type 1.5 or slow onset type 1, and diabetes insipidus.
Genetics and The Environment:
The two main types of diabetes are type 1 and type 2. They have different causes and may require different treatment approaches. But both have one thing in common: a genetic factor. With both types of diabetes you must inherent the predisposition for diabetes (almost always from both parents) and second, something in the environment must trigger the disease.
Twin studies show that genetic predisposition to diabetes is not enough to become diabetic. Only half of identical twins with a diabetic twin sibling will also become type 1 diabetic. However, the likelihood of an identical twin developing type 2 diabetes when a twin sibling has type 2 is much greater with a 75% chance of type 2 onset.
Type 1 Diabetes
Even with a genetic predisposition for developing diabetes most people still do not get it. This is why researchers focus on what environmental triggers contribute to the onset of diabetes in people. More people are diagnosed with type 1 diabetes during winter months as well as in colder climates in general, so cold weather is a suspected environmental trigger. Another trigger seems to be a virus, and diabetes is less common in breast-fed infants than those who started solid food at an early age.
People with diabetes often test positive (even years before onset) for a certain kind of autoantibody. Antibodies are normally good; a protein that attack and destroy bacteria and viruses that invade the body. But in diabetes autoantibodies (“auto” meaning self) mistake healthy cells for bad ones and these autoantibodies attack and destroy the insulin producing beta cells in the pancreas.
People with type 1 diabetes may often also have autoantibodies for Hashimoto’s thyroiditis. In this case, the thyroid gland is attacked and destroyed and a person may end up with hypothyroid (low thyroid) and require medication. Women with diabetes (type 1 or 2) may also have another autoimmune problem called polycystic ovarian syndrome (PCOS).
Type 2 Diabetes
Type 2 diabetes has a more significant genetic basis than type 1, but it too also depends more on environmental factors than genes. A familial history of type 2 is a strong risk factor indicator for other family members but this seems to only really matter to Americans and Europeans. Lifestyle, the biggest environmental trigger for type 2, plays a large role in which genetically predispositioned individuals will eventually become diabetic. Those most affected in the United States are African Americans, Mexican Americans, and Pima Indians. A sedentary lifestyle, coupled with a diet high in fat, processed carbohydrates, and low in fiber are a recipe for developing type 2 diabetes. Obesity is also a risk factor for developing type 2 and insulin resistance often seen in obese persons can be a pre-cursor to developing type 2. The younger an obese person is (i.e., children), and the length of time a person has been obese increase the risk factor for developing type 2. Persons in other cultures, who have not adopted a “Westernized” lifestyle, do not seem to develop type 2 diabetes even when a genetic predisposition to diabetes is present.
Women who have a family history of diabetes, especially on the maternal side are more likely to develop gestational diabetes than other women. As with type 1 and type 2, gestational diabetes is also greatly affected by non-genetic factors such as age (older women are more likely to develop gestational diabetes than young women) and being overweight.
Every woman who has had gestational diabetes should have an annual blood test to check for hyperglycemia (high levels of blood glucose). Since 20 to 50 percent of women with GD will develop diabetes later in life, it is important to be aware of the symptoms of type 2 diabetes. Women with GD during one pregnancy have a 50% chance of developing GD with subsequent pregnancies.
See "Genetic Transmission of Type 2 Diabetes," below, for how having gestational diabetes may affect your child's risk of developing type 2 diabetes later in life.
Note: Babies are not born with type 1 or type 2 diabetes simply as a result of being born to a mother with gestational diabetes but they are at increased risk for birth defect and complications during delivery.
Genetic Transmission Rates for Diabetes
Genetic Transmission of Type 1 Diabetes:
An exception to transmission data above is for those who have a condition called type 2 polyglandular autoimmune syndrome. About 1 in every 7 type 1 diabetics have this syndrome. Those with this syndrome not only have diabetes but a thyroid disease and inadequately function adrenal gland, and some even have more immune system disorders such as polycystic ovarian syndrome (women). For those who have type 2 polyglandular autoimmune syndrome, children will develop this syndrome and type 1 diabetes 50% of the time.
There are genetic tests that can be conducted to help predict your child’s odds of developing type 1. Most Caucasians with type 1 have either HLA-DR3 or HLA-DR4 genes. If you and your child are Caucasian and share these genes, your child has greater risk of developing type 1.
Parents who have a rare form of diabetes called maturity-onset diabetes of the young (MODY), their child has almost a 1-in-2 chance of getting it, too.
Glucose tolerance tests can be performed with children, as well as test to measure antibodies to insulin, especially if there are siblings with type 1. This test measures antibodies to insulin, to islet cells in the pancreas, or to an enzyme called glutamic acid decarboxylase. High levels can indicate that a child has a higher risk of developing type 1 diabetes.Oral Glucose Tolerance Test Ranges (non-pregnant)
Oral Glucose Tolerance Test (pregnancy)
Genetic Transmission of Type 2:
(2) It is suspected that maternal transmission is more likely than paternal transmission. However, if both parents are type 2 their child has a 50/50 chance of becoming type 2 diabetic as well.
(3) Every woman who has had gestational diabetes should have an annual blood test to check for hyperglycemia (high levels of blood glucose). Since 20 to 50 percent of women with GD will develop diabetes later in life, it is important to be aware of the symptoms of type 2 diabetes. Women with GD during one pregnancy have a 50% chance of developing GD with subsequent pregnancies
Page Updated 08/16/2006