Diabetes International Foundation - Different Types of Diabetes Type 1Type 1 is an autoimmune disease, and people require insulin at diagnosis. Usually the diagnosis is in childhood, adolescence or early adulthood, but not always (people can be diagnosed with type 1 at any age). People with type 1 diabetes, previously called insulin-dependent diabetes mellitus or juvenile-onset diabetes, are unable to produce insulin properly, if at all. Type 1 diabetes develops when the body's immune system destroys pancreatic beta cells, the only cells in the body that make the hormone insulin that regulates blood glucose. To survive, people with type 1 diabetes must have insulin delivered by injection or an insulin pump. There is no known way to prevent type 1 diabetes. Several clinical trials of methods to prevent type 1 diabetes are currently in progress. Type 2Type 2 isn’t autoimmune, and it may take years before a person requires insulin, if at all. People with type 2 diabetes, previously called non-insulin-dependent diabetes mellitus or adult-onset diabetes, can produce insulin, but their cells don't respond to it properly. As the need for insulin rises, the pancreas gradually loses its ability to produce it. Type 2 diabetes is associated with older age, obesity, lack of physical activity, family history of diabetes, and history of gestational diabetes. Gestational DiabetesGestational diabetes develops during pregnancy. Like other types of diabetes, gestational diabetes affects how your cells use sugar (glucose) - your body's main fuel. Gestational diabetes causes high blood sugar that can affect your pregnancy and your baby's health. In gestational diabetes, blood sugar usually returns to normal soon after delivery. But if you've had gestational diabetes, you are at risk for future type 2 diabetes. It is recommended that you continue working with your health care provider to monitor and manage your blood sugar. Latent Autoimmune Diabetes (LADA)LADA is a slowly progressing version of type 1 with some of the characteristics of type 2. Some people call it type 1.5. People with LADA have antibodies to the disease like those with type 1 but they don’t need insulin right away. Often times their blood glucose can be controlled on lifestyle or oral agents for months or even years. Type 1, type 2, gestational diabetes and LADA are polygenic. This means that it takes the involvement of many genes to cause the disease. But there are other, much rarer forms of diabetes that are monogenic, meaning a change in only one gene is responsible for the condition. There are two types: Maturity Onset Diabetes of the Young (MODY) and Neonatal Diabetes Mellitus (NDM). Maturity Onset Diabetes of the Young(MODY)Between 1 and 5% of people diagnosed with diabetes are thought to have MODY.MODY is a monogenic form of diabetes that is often confused with type 1 or type 2 diabetes. MODY decreases the amount of insulin a person's body makes, which in turn limits the body's ability to control the amount of sugar (glucose) in the blood. Too much sugar in the body's blood can damage body tissue, particularly the eyes, kidneys, nerves, and blood vessels. MODY usually presents in childhood or adolescence but because its symptoms are often mild, many are not diagnosed until much later. Unlike those with type 2, people with MODY are usually of normal weight and don’t have high blood pressure or high cholesterol levels. This means that patients who really have MODY may not know it and may not be getting the right type of treatment. Genetic testing is often recommended if there is a history of diabetes in successive generations in the family—grandparent, parent and child. Most often people with MODY can be treated with lifestyle changes or oral agents and give up carb counting, insulin injections and/or insulin pump therapy. See below for "Frequently Asked Questions About MODY". Neonatal Diabetes Mellitus (NDM)Type 1 diabetes is usually diagnosed after the first 6 months of age. But there is a rare condition called neonatal diabetes mellitus that can occur from birth to 6 months. Unlike other forms of diabetes, about half of the cases of NDM are temporary. This type of diabetes will disappear in infancy, although it may come back in adulthood. The other half of the cases will continue to have diabetes throughout their lives. See below for "Frequently Asked Questions About Neonatal Diabetes". The following information has been provided by The Kovler Diabetes Center at the University of Chicago Medical Center. FREQUENTLY ASKED QUESTIONS ABOUT "MODY" What is MODY?Maturity-onset diabetes of the young, or MODY, is a form of monogenic diabetes that is caused by mutations in a number of different genes. Each different mutated gene causes a slightly different type of diabetes.MODY is typically diagnosed in late childhood, adolescence, or early adulthood. However, it has been known to develop in adults as late as their 50s. Many people with MODY are misdiagnosed as having type 1 or type 2 diabetes. However, a diagnosis of MODY could change the course of treatment and could help to identify other family members with MODY. How many people have MODY?It is believed that up to 2 percent of all diabetes cases are due to MODY. Who should be tested for MODY? A diabetes patient who is part of a family with three or more consecutive generations affected by diabetesA diabetes patient with stable, mildly elevated blood sugars, often found incidentally during a routine check-upA “type 1″ diabetes patient who has negative blood testing for autoantibodies, typically done at the time of diabetes diagnosis (antibodies typically tested include one or more of the following: GAD65, islet cell or ICA, IA-2, insulin, ZnT8)A “type 1″ diabetes patient who generates a significant amount of insulin years beyond diagnosis (detectable blood levels of c-peptide, proinsulin, and/ or insulin)A “type 2″ diabetes patient who is normal weight or not significantly overweight and shows no signs of insulin resistanceDiabetes paired with pancreatic insufficiency (the digestive role of the pancreas is impaired with symptoms such as diarrhea and gas)Individual or family history of diabetes paired with developmental kidney disease or abnormalities of the kidney (especially cysts). The urinary system and reproductive organs may also be abnormally formed. Will treatment change if I have MODY?That depends on the type of MODY. MODY caused by mutations in the HNF1A or HNF4A genes often, though not always, responds well to low doses of sulfonylureas. MODY due to mutations in GCK typically requires no treatment at all. The best treatment for other MODY types is unclear and varies from one person to the next. If I have MODY, can I pass it on to my children?MODY is an autosomal dominant disease. That means that each child will have a 50% chance of inheriting the gene mutation that can cause MODY. It also means that if you have MODY and your siblings or parent have diabetes, they are very likely to have MODY too. FREQUENTLY ASKED QUESTIONS ABOUT "NEONATAL DIABETES" What is neonatal diabetes?Neonatal diabetes can be permanent (permanent neonatal diabetes mellitus, PNDM) or transient (transient neonatal diabetes mellitus, TNDM). In PNDM, the diabetes requires treatment for the person’s entire life. In TNDM, the diabetes may go away and no longer require treatment after the first few months of life. However, the diabetes will often return later in life. It is very important to have genetic testing done to help guide treatment, prognosis and monitoring for diabetes recurrence. How many people have neonatal diabetes?Neonatal diabetes is very rare. About 1 in 100,000 babies born have neonatal diabetes. Who should be tested for neonatal diabetes?Anyone diagnosed with diabetes at 12 months of age or younger should be tested for monogenic neonatal diabetes. Can genetic forms of diabetes diagnosed at or under 12 months of age be distinguished from type 1 diabetes without genetic testing? A diagnosis of diabetes before 6 months of age makes monogenic neonatal diabetes much more likely than type 1 diabetes. However, it can be hard to tell them apart: in both types, elevated levels of glucose (sugar) in the blood can cause symptoms of frequent urination, severe thirst and dehydration. In extreme cases, the baby may experience ketoacidosis, a condition in which acid levels in the body rise to very dangerous or even life-threatening levels. The only definitive way to diagnose monogenic neonatal diabetes is with genetic testing. If my child has neonatal diabetes, can he/she be treated with pills?There is a possibility that your child can transition from insulin injections to pills (sulfonylureas). However, this change is only possible with certain types of neonatal diabetes (such as those caused by mutations in the KCNJ11 or ABCC8 genes). Any treatment changes and the best treatment for your child should be decided by his or her physician. Important Information Regarding Diabetes The following information has been provided by Dr. Louis Philipson, Director, Kovler Diabetes Center at the University of Chicago Medical Center. At The Kovler Diabetes Center, we know there are in fact many kinds of diabetes and at least some of them can be seen at any age. Type 1 diabetes use to be thought of as occurring primarily in children, but this was always a misconception. While the peak ages for type 1 diabetes occur in the childhood to adolescent age group, I have had adult patients as old as 80 years of age receive a new diagnosis Type 1. The first thing (but not the only thing!) to consider is the BMI (body mass index). Lean patients are much more likely to have type 1 diabetes or some other form of insulin-deficient diabetes (like monogenic, see below). If the blood sugar is over 250 mg/dl it is very important to consider getting ketone levels. A positive test for acetone or other ketones is not definitive for type 1 but it should raise suspicions when the blood sugar is high. Adults with type 1 often have a much slower time of progression of their disease, which can also be confusing. Children can appear to develop diabetes practically overnight requiring insulin right away, whereas adults with type 1 might take several years of progressive failure of one oral agent after another until insulin is finally started. This is also known as LADA – latent adult onset diabetes with autoimmunity. The autoimmunity part is really critical. Most but not all patients with type 1 will be positive for auto-antibodies against proteins of the beta cell. Typically we test for anti-GAD65, anti-IA2, anti-insulin, anti-ICA, and/or antiZnT8 antibodies. A positive test in any one of these is consistent with autoimmune type 1 diabetes, and insulin is the only appropriate therapy, although combinations that include insulin can often be helpful. The family history can also provide important insights. Patients with type 2 diabetes actually have a positive family history of type 2 diabetes much more often than patients with type 1 diabetes. Finally in some cases measuring the insulin levels can be helpful if they are high or very low. This is usually done by measuring the c-peptide level, a by-product of insulin secretion that was discovered at the University of Chicago. There are many caveats to this test so by itself it might be misleading in a non-research setting. I should point out that there are other important forms of diabetes. Most primary care providers would be familiar with steroid-induced diabetes and gestational diabetes. While steroid-induced is a form of Type 2, gestational could be either type 1 or type 2 or monogenic and should be investigated further. Diabetes can also be associated with acromegaly, thyroid disease, and cystic fibrosis, for example. Our team studies rare forms of diabetes that are strongly inherited – the monogenic forms. These are described on our website www.kovlerdiabetescenter.org and several of them were also discovered here at the University of Chicago. These also have the hallmarks of young onset, are antibody negative, and usually positive for tests of insulin production such as the c-peptide test. They are important because they can have specific outcomes, specific treatments, and specific associated factors. They also tell us about genes that are important for normal metabolism. They occur in about 2% of everyone with diabetes, meaning about 3-500,000 people in the United States alone have one of these forms – a significant number that is largely missed. The bottom line here is that Type 1 diabetes is increasing in many populations, although perhaps not as dramatically as Type 2 diabetes associated with obesity. Missing type 1 diabetes can be a disaster, or at best a multiyear confusion. What I teach is that it is always important to ask oneself why a given patient has diabetes and what kind they have. Do not assume. If you have doubts, get another opinion, or get a referral to a see a specialist. Persistence can be life-saving. Dr. Louis Philipson, DirectorKovler Diabetes Center at the University of Chicago Medical Center To find detailed information and symptoms of Different Types of Diabetes, please visit the following website: www.kovlerdiabetescenter.org

Type 1 is an autoimmune disease, and people require insulin at diagnosis. Usually the diagnosis is in childhood, adolescence or early adulthood, but not always (people can be diagnosed with type 1 at any age). People with type 1 diabetes, previously called insulin-dependent diabetes mellitus or juvenile-onset diabetes, are unable to produce insulin properly, if at all. Type 1 diabetes develops when the body's immune system destroys pancreatic beta cells, the only cells in the body that make the hormone insulin that regulates blood glucose. To survive, people with type 1 diabetes must have insulin delivered by injection or an insulin pump. There is no known way to prevent type 1 diabetes. Several clinical trials of methods to prevent type 1 diabetes are currently in progress.

Type 2

Type 2 isn’t autoimmune, and it may take years before a person requires insulin, if at all. People with type 2 diabetes, previously called non-insulin-dependent diabetes mellitus or adult-onset diabetes, can produce insulin, but their cells don't respond to it properly. As the need for insulin rises, the pancreas gradually loses its ability to produce it. Type 2 diabetes is associated with older age, obesity, lack of physical activity, family history of diabetes, and history of gestational diabetes.

Gestational Diabetes

Gestational diabetes develops during pregnancy. Like other types of diabetes, gestational diabetes affects how your cells use sugar (glucose) - your body's main fuel. Gestational diabetes causes high blood sugar that can affect your pregnancy and your baby's health. In gestational diabetes, blood sugar usually returns to normal soon after delivery. But if you've had gestational diabetes, you are at risk for future type 2 diabetes. It is recommended that you continue working with your health care provider to monitor and manage your blood sugar.

Latent Autoimmune Diabetes (LADA)

LADA is a slowly progressing version of type 1 with some of the characteristics of type 2. Some people call it type 1.5. People with LADA have antibodies to the disease like those with type 1 but they don’t need insulin right away. Often times their blood glucose can be controlled on lifestyle or oral agents for months or even years.

Type 1, type 2, gestational diabetes and LADA are polygenic. This means that it takes the involvement of many genes to cause the disease. But there are other, much rarer forms of diabetes that are monogenic, meaning a change in only one gene is responsible for the condition. There are two types: Maturity Onset Diabetes of the Young (MODY) and Neonatal Diabetes Mellitus (NDM).

Maturity Onset Diabetes of the Young(MODY)

MODY is a monogenic form of diabetes that is often confused with type 1 or type 2 diabetes. MODY decreases the amount of insulin a person's body makes, which in turn limits the body's ability to control the amount of sugar (glucose) in the blood. Too much sugar in the body's blood can damage body tissue, particularly the eyes, kidneys, nerves, and blood vessels. MODY usually presents in childhood or adolescence but because its symptoms are often mild, many are not diagnosed until much later. Unlike those with type 2, people with MODY are usually of normal weight and don’t have high blood pressure or high cholesterol levels. This means that patients who really have MODY may not know it and may not be getting the right type of treatment.

Genetic testing is often recommended if there is a history of diabetes in successive generations in the family—grandparent, parent and child. Most often people with MODY can be treated with lifestyle changes or oral agents and give up carb counting, insulin injections and/or insulin pump therapy.

Neonatal Diabetes Mellitus (NDM)

Type 1 diabetes is usually diagnosed after the first 6 months of age. But there is a rare condition called neonatal diabetes mellitus that can occur from birth to 6 months. Unlike other forms of diabetes, about half of the cases of NDM are temporary. This type of diabetes will disappear in infancy, although it may come back in adulthood. The other half of the cases will continue to have diabetes throughout their lives.

The following information has been provided by The Kovler Diabetes Center at the University of Chicago Medical Center.

Maturity-onset diabetes of the young, or MODY, is a form of monogenic diabetes that is caused by mutations in a number of different genes. Each different mutated gene causes a slightly different type of diabetes.

MODY is typically diagnosed in late childhood, adolescence, or early adulthood. However, it has been known to develop in adults as late as their 50s. Many people with MODY are misdiagnosed as having type 1 or type 2 diabetes. However, a diagnosis of MODY could change the course of treatment and could help to identify other family members with MODY.

How many people have MODY?

It is believed that up to 2 percent of all diabetes cases are due to MODY.

Who should be tested for MODY?

A diabetes patient who is part of a family with three or more consecutive generations affected by diabetes
A diabetes patient with stable, mildly elevated blood sugars, often found incidentally during a routine check-up
A “type 1″ diabetes patient who has negative blood testing for autoantibodies, typically done at the time of diabetes diagnosis (antibodies typically tested include one or more of the following: GAD65, islet cell or ICA, IA-2, insulin, ZnT8)
A “type 1″ diabetes patient who generates a significant amount of insulin years beyond diagnosis (detectable blood levels of c-peptide, proinsulin, and/ or insulin)
A “type 2″ diabetes patient who is normal weight or not significantly overweight and shows no signs of insulin resistance
Diabetes paired with pancreatic insufficiency (the digestive role of the pancreas is impaired with symptoms such as diarrhea and gas)
Individual or family history of diabetes paired with developmental kidney disease or abnormalities of the kidney (especially cysts). The urinary system and reproductive organs may also be abnormally formed.

Will treatment change if I have MODY?

That depends on the type of MODY. MODY caused by mutations in the HNF1A or HNF4A genes often, though not always, responds well to low doses of sulfonylureas. MODY due to mutations in GCK typically requires no treatment at all. The best treatment for other MODY types is unclear and varies from one person to the next.

If I have MODY, can I pass it on to my children?

MODY is an autosomal dominant disease. That means that each child will have a 50% chance of inheriting the gene mutation that can cause MODY. It also means that if you have MODY and your siblings or parent have diabetes, they are very likely to have MODY too.

Neonatal diabetes can be permanent (permanent neonatal diabetes mellitus, PNDM) or transient (transient neonatal diabetes mellitus, TNDM). In PNDM, the diabetes requires treatment for the person’s entire life. In TNDM, the diabetes may go away and no longer require treatment after the first few months of life. However, the diabetes will often return later in life. It is very important to have genetic testing done to help guide treatment, prognosis and monitoring for diabetes recurrence.

How many people have neonatal diabetes?

Neonatal diabetes is very rare. About 1 in 100,000 babies born have neonatal diabetes.

Who should be tested for neonatal diabetes?

Anyone diagnosed with diabetes at 12 months of age or younger should be tested for monogenic neonatal diabetes.

Can genetic forms of diabetes diagnosed at or under 12 months of age be distinguished from type 1 diabetes without genetic testing?

A diagnosis of diabetes before 6 months of age makes monogenic neonatal diabetes much more likely than type 1 diabetes. However, it can be hard to tell them apart: in both types, elevated levels of glucose (sugar) in the blood can cause symptoms of frequent urination, severe thirst and dehydration. In extreme cases, the baby may experience ketoacidosis, a condition in which acid levels in the body rise to very dangerous or even life-threatening levels. The only definitive way to diagnose monogenic neonatal diabetes is with genetic testing.

If my child has neonatal diabetes, can he/she be treated with pills?

There is a possibility that your child can transition from insulin injections to pills (sulfonylureas). However, this change is only possible with certain types of neonatal diabetes (such as those caused by mutations in the KCNJ11 or ABCC8 genes). Any treatment changes and the best treatment for your child should be decided by his or her physician.

Important Information Regarding Diabetes

The following information has been provided by Dr. Louis Philipson, Director, Kovler Diabetes Center at the University of Chicago Medical Center.

At The Kovler Diabetes Center, we know there are in fact many kinds of diabetes and at least some of them can be seen at any age. Type 1 diabetes use to be thought of as occurring primarily in children, but this was always a misconception. While the peak ages for type 1 diabetes occur in the childhood to adolescent age group, I have had adult patients as old as 80 years of age receive a new diagnosis Type 1.

The first thing (but not the only thing!) to consider is the BMI (body mass index). Lean patients are much more likely to have type 1 diabetes or some other form of insulin-deficient diabetes (like monogenic, see below). If the blood sugar is over 250 mg/dl it is very important to consider getting ketone levels. A positive test for acetone or other ketones is not definitive for type 1 but it should raise suspicions when the blood sugar is high. Adults with type 1 often have a much slower time of progression of their disease, which can also be confusing. Children can appear to develop diabetes practically overnight requiring insulin right away, whereas adults with type 1 might take several years of progressive failure of one oral agent after another until insulin is finally started. This is also known as LADA – latent adult onset diabetes with autoimmunity. The autoimmunity part is really critical. Most but not all patients with type 1 will be positive for auto-antibodies against proteins of the beta cell. Typically we test for anti-GAD65, anti-IA2, anti-insulin, anti-ICA, and/or antiZnT8 antibodies. A positive test in any one of these is consistent with autoimmune type 1 diabetes, and insulin is the only appropriate therapy, although combinations that include insulin can often be helpful. The family history can also provide important insights. Patients with type 2 diabetes actually have a positive family history of type 2 diabetes much more often than patients with type 1 diabetes. Finally in some cases measuring the insulin levels can be helpful if they are high or very low. This is usually done by measuring the c-peptide level, a by-product of insulin secretion that was discovered at the University of Chicago. There are many caveats to this test so by itself it might be misleading in a non-research setting.

I should point out that there are other important forms of diabetes. Most primary care providers would be familiar with steroid-induced diabetes and gestational diabetes. While steroid-induced is a form of Type 2, gestational could be either type 1 or type 2 or monogenic and should be investigated further. Diabetes can also be associated with acromegaly, thyroid disease, and cystic fibrosis, for example.

Our team studies rare forms of diabetes that are strongly inherited – the monogenic forms. These are described on our website www.kovlerdiabetescenter.org and several of them were also discovered here at the University of Chicago. These also have the hallmarks of young onset, are antibody negative, and usually positive for tests of insulin production such as the c-peptide test. They are important because they can have specific outcomes, specific treatments, and specific associated factors. They also tell us about genes that are important for normal metabolism. They occur in about 2% of everyone with diabetes, meaning about 3-500,000 people in the United States alone have one of these forms – a significant number that is largely missed.

The bottom line here is that Type 1 diabetes is increasing in many populations, although perhaps not as dramatically as Type 2 diabetes associated with obesity. Missing type 1 diabetes can be a disaster, or at best a multiyear confusion. What I teach is that it is always important to ask oneself why a given patient has diabetes and what kind they have. Do not assume. If you have doubts, get another opinion, or get a referral to a see a specialist. Persistence can be life-saving.

To find detailed information and symptoms of Different Types of Diabetes, please visit the following website: