Diabetes (otherwise known as diabetes mellitus, DM) is described as a metabolic disorder in which the body cannot properly store and use the energy found in food.
More specifically, diabetes is a condition that affects the body's ability to use glucose (a type of sugar) as fuel. Glucose is a form of carbohydrate that comes from foods such as breads, cereals, pasta, rice, potatoes, fruits and some vegetables. Glucose is also synthesized in the liver and is carried in the blood to the rest of the body to fuel cellular processes.
To use glucose as fuel, insulin is required to get the glucose into cells. Insulin is a hormone (a type of chemical messenger) made by specialized cells in the pancreas. Insulin regulates blood glucose by stimulating the removal of glucose from the blood and its uptake into muscle, liver and fat cells where it can be stored for energy.
Sometimes the body does not make enough insulin or the cells do not respond properly to insulin. Blood glucose levels can then become elevated while the cells are deprived of fuel. When blood glucose levels get too high (hyperglycemia) this can cause damage to the tiny blood vessels in the eyes, kidneys, heart and nervous system, which is why diabetes is associated with an increased risk of cardiovascular disease, kidney disease, loss of vision and neurological conditions.
Persistently elevated blood glucose may lead to a diagnosis of prediabetes or diabetes. Prediabetes describes the condition where blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes.
There are three types of diabetes:
Type 1 diabetes used to be known as insulin-dependent diabetes (IDDM), or juvenile-onset diabetes as it often begins in childhood. Type 1 diabetes is an autoimmune condition where the immune system wrongly identifies and subsequently attacks the pancreatic cells that produce insulin, leading to little or no insulin production.
Type 2 diabetes used to be known as non-insulin dependent diabetes (NIDDM) and adult onset diabetes, but it is increasingly common in children, largely due to children being more likely to be obese or overweight. In this condition, the body usually still produces some insulin, but this is not enough to meet demand and the body's cells do not properly respond to the insulin. The latter effect is called insulin resistance, where persistently elevated blood glucose has caused cells to be overexposed to insulin, making them less responsive or unresponsive to the hormonal messenger.
Gestational diabetes occurs in pregnancy and typically resolves after childbirth. People who have experienced gestational diabetes do, however, have an increased risk of developing type 2 diabetes after pregnancy.
Contents of this article:
You will also see introductions at the end of some sections to any recent developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Fast facts on diabetes
- 29.1 million children and adults in the United States - 9.3% of the population - have diabetes (21 million diagnosed, and an estimated 8.1 million undiagnosed).12
- 1.7 million new cases of diabetes were diagnosed in people aged 20 years and older in 2012.
- 15.5 million, or 13.6% of all men aged 20 years or older have diabetes.
- 13.4 million, or 11.2% of all women aged 20 years or older have diabetes.
- 37% of Americans aged 20 years or older have prediabetes.
- Diabetes is present in 15.9% of American Indians/Alaska Natives, 13.2% of non-Hispanic blacks, 12.8% of Hispanics, 9% of Asian Americans, and 7.6% of non-Hispanic whites.
- Diabetes contributed to 231,404 deaths in the US in 2007.2
- $245 billion: Total costs of diagnosed diabetes in the United States in 2012.2
- Only 5% of people with diabetes have type 1 diabetes, which is an autoimmune disease involving caused by genetic, environmental, and other factors.2
- Type 2 diabetes accounts for 95% of diabetes cases and is usually associated with older age, obesity and physical inactivity, family history of type 2 diabetes, or a personal history of gestational diabetes.2
- There is no known way to prevent diabetes type 1. Effective treatment requires the use of replacement insulin.
- Type 2 diabetes can be prevented through healthy food choices, physical activity, and weight management. It can also be managed through lifestyle and diet, although insulin or oral medication may be necessary for some people.
The difference between diabetes type 1 and type 2
There are two main types of diabetes, type 1 diabetes and type 2 diabetes. These two diabetes types have several key differences, for instance the differences in cause, symptoms, characteristics, management, incidence, who it affects and what effects the disease has on the body.
The easiest way to find out the differences, as well as similarities between the two, is through comparing the type 1 with type 2 diabetes. Comparisons will be made across the various sections in this page.
Recommended target blood glucose level ranges for non-diabetic and diabetes type 1 and type 2
For the majority of healthy individuals, normal blood glucose level in humans is about 4 mmol/L or 72 mg/dL.3-5
|Target glucose levels
2 hours after meals
|Non-diabetic||4.0 to 5.9 mmol/L||Under 7.8 mmol/L|
|Diabetes type 2||4 to 7 mmol/L||Under 8.5 mmol/L|
|Diabetes type 1||4 to 7 mmol/L||Under 9 mmol/L|
|Children with diabetes type 1||4 to 8 mmol/L||Under 10 mmol/L|
What causes diabetes type 1 and type 2?
Type 1 diabetes occurs when the body's immune system erroneously attacks the pancreatic beta cells, which produce insulin, destroying these cells and reducing the body's ability to produce sufficient insulin to regulate blood glucose levels.
Type 2 diabetes is a condition where the body does not produce sufficient insulin and the body's cells become resistant to the effects of insulin. This results in the build-up of glucose in the blood while cells are starved of energy. This condition is often a result of persistently high glucose levels as well as obesity and overweight, lifestyle and dietary factors, medications and other issues.
Insulin use not only prevents hyperglycemic emergencies, but is a safeguard that helps to prevent long-term complications of diabetes by correcting fasting and postprandial (after meal) hyperglycemia.
Both of the major types of diabetes typically include different stages of disease, beginning with a state where supplemental insulin is not required to a state that does require exogenous insulin for blood glucose control and survival.
|Diabetes type 16,7||Diabetes type 26,7|
|Cause||Beta cells in pancreas are attacked by the body's own immune system, therefore reducing insulin production, leading to elevated blood glucose. Insulin is not produced or is produced in insufficient amounts.||Persistently high intakes of dietary sugars leads to excess demands on insulin production, which leads to insulin resistance over time. Receptor cells that have become less sensitive (resistant) to insulin are unable to remove glucose from the blood, leading to higher blood glucose and greater demands on insulin production.|
|Genetic basis||Possibly. In most cases of type 1 diabetes, the patient would need to inherit risk factors from both parents.||Type 2 diabetes has a stronger link to family history and lineage than type 1.|
|Bodily effects||Thought to be triggered by autoimmune destruction of the beta cells. Autoimmune attack may occur following a viral infection such as mumps, rubella cytomegalovirus.||Appears to be related to aging, inactive lifestyle, diet, genetic influence and obesity.|
|Climate||One trigger might be related to cold weather. Type 1 diabetes develops more often in winter than summer and is more common in places with cold climates.||Type 2 diabetes is more common in people with low levels of vitamin D, which is synthesized from sunlight. Vitamin D supports immune function and insulin sensitivity, meaning that those living at a more northerly latitude may face a higher risk of diabetes.13|
|Diet||Early diet may also play a role. Type 1 diabetes is less common in people who were breastfed and in those who first ate solid foods at later ages.||Obesity tends to run in families, and families tend to have similar eating and exercise habits. Diets high in simple sugars and low in fibre and vital nutrients are more likely to lead to diabetes.|
Recent developments on diabetes type 1 and type 2 causes from MNT news
Researchers from Imperial College London in the UK have found that babies born by cesarean section are more likely to be overweight or obese in adulthood than those born by vaginal delivery. These babies are more likely to develop asthma or type 1 diabetes during childhood.
Scientists have discovered a genetic deficiency in males that could prompt the development of the most common type of liver cancer and type 2 diabetes.
On the next page we look at the signs and symptoms of type 1 and type 2 diabetes as well as tests and diagnosis and the treatments for each diabetes type.