Type 2 Diabetes Quick Overview
- Type 2 diabetes is a chronic medical
condition that results from an inability of the body to properly use insulin.
- Type 2 diabetes is different from
1 diabetes, in which the body is unable to produce sufficient levels of insulin.
- Symptoms of type 2 diabetes include
- Risk factors for getting
type 2 diabetes include
- genetics (family history),
- fatty waistline (apple shape),
- inactivity, and
- older age.
- A fasting blood sugar level of 126
mg/dl or greater on two different days establishes the diagnosis of diabetes.
- A number of both oral and injectable
medications have been developed fo
- A hemoglobin A1c (HBA1c) level of 6.5%
or greater indicates diabetes.
- Managing type 2 diabetes includes following a healthy eating plan and exercise, as well as medications in many cases.
- r the treatment of type 2 diabetes.
- A healthy eating plan and regular
physical activity are important components of a type 2 diabetes treatment plan.
- There is no one recommended "diabetes
diet" for all people with type 2 diabetes.
- Regular physical activity and modest
weight loss can help reduce or prevent type 2 diabetes.
- Common complications of diabetes
include cardiovascular disease, kidney disease,
eye problems, and
- Good control of blood sugar levels can
prevent complications of type 2 diabetes.
What Is Type 2 Diabetes?
Type 2 diabetes is the most common form of diabetes mellitus. In type 2 diabetes, there is an elevated level of sugar (glucose) in the bloodstream due to the body's inability to properly respond to insulin. Insulin is a hormone that allows the body to utilize glucose for energy. Insulin is produced by specialized cells in the pancreas. An elevated level of blood glucose is known as hyperglycemia. The excessive levels of glucose in the blood spill over into the urine, leading to the presence of glucose in the urine (glucosuria).
Type 2 diabetes is an enormous public health problem. It is estimated that about 29.1 million Americans (9.1% of all Americans) have type 2 diabetes. The US Centers for Disease Control and Prevention reported that around 40% of adults in the US will develop diabetes, primarily type 2, in their lifetime. Among ethnic minorities, over half will develop diabetes in their lifetime. Increasing rates of obesity is thought to be responsible for the increasing incidence of diabetes. Almost 28% of people living with diabetes are thought to be unware of their condition.
Type 2 diabetes is a chronic condition that arises slowly over time and persists throughout an individual's lifetime. Over time, people with diabetes can develop complications of the disease that lead to damage to multiple organs. Complications of diabetes include
Good control of the disease can minimize the risk of complications.
Can eating too much sugar cause diabetes?
It's a myth that simply eating too much sugar causes diabetes. Type 1 diabetes is genetic, and it is unknown what triggers the disease, while type 2 diabetes is a combination of genetics and lifestyle.
Where sugar enters the equation is that being overweight is a risk factor for developing type 2 diabetes, and a diet high in calories and sugar can contribute to weight gain.
What Are the Symptoms of Type 2 Diabetes?
Symptoms and signs of type 1 and type 2 diabetes can be similar. Symptoms and signs of poorly controlled diabetes (or undiagnosed diabetes) can include:
Other symptoms, while characteristic of the complications that arise from long-term untreated or poorly-treated diabetes, may be the initial symptoms in some people who do not know they have diabetes. These symptoms include
What Causes, and What Are the Risk Factors for Type 2 Diabetes?
Type 2 diabetes is the result of the body not being able to effectively use insulin, and is referred to as insulin resistance. Because patients with type 2 diabetes can still produce insulin even though the body does not respond properly, blood levels of insulin can become elevated in some people with the condition. In some, the pancreas may not be able to properly release insulin that is produced.
Risk factors for type 2 diabetes
- Genetics is a strong risk factor for the development of type 2 diabetes. Those who have relatives with the condition are at greater risk.
- Obesity is another major risk factor. There is a direct relationship between the severity of obesity and the likelihood of getting type 2 diabetes. This is also true for children and teens.
- Distribution of body fat: Storing excess body fat around the waist is linked to a higher risk than storing fat in the hips and thighs.
- Age is a risk factor for type 2 diabetes. The incidence increases with advancing age. There is an increase in type 2 diabetes with each decade over the age of 40, independent of weight.
- Ethnicity: Certain racial and ethnic groups are more likely than others to develop type 2 diabetes. In particular, type 2 diabetes is most likely to occur in Native Americans (affecting 20%-50% of the population). It is also more common in African Americans, Hispanics/Latinos, and Asian Americans than in Caucasian Americans.
- Gestational diabetes: Women who had diabetes during pregnancy (gestational diabetes) are at increased risk for subsequently developing type 2 diabetes.
- Sleep disorders: Untreated sleep disorders, particularly sleep apnea, are associated with an increased risk for type 2 diabetes.
- Inactivity: Being physically active decreases the chance of getting type 2 diabetes.
- Polycystic ovary syndrome (PCOS): Women with this condition have an increased likelihood of developing type 2 diabetes.
What Is the Difference Between Type 1 and Type 2 Diabetes?
Elevated blood sugar (hyperglycemia) is the hallmark of both type 1 and type 2 diabetes. Type 1 diabetes results from an autoimmune reaction of the body against the cells of the pancreas that produce insulin. The pancreas is then unable to produce sufficient insulin. In contrast, patients with type 2 diabetes are able to produce insulin, but the body is unable to respond properly to the insulin (known as insulin resistance).
- Type 1 diabetes more commonly affects young people (under 30), and it was formerly referred to as juvenile diabetes and insulin-dependent diabetes, because patients with this condition must be treated with insulin.
- Type 2 diabetes was formerly known as adult-onset diabetes or non-insulin-dependent diabetes.
- About 10% of people with diabetes have type 1 diabetes while the remainder have type 2 diabetes.
- While type 1 diabetes typically begins in younger people, some adults experience a late onset of type 1 diabetes (latent autoimmune diabetes in adults, or LADA), and it is possible for children and adolescents to develop type 2 diabetes.
What Type of Doctor Treats Type 2 Diabetes?
Endocrinologists are the medical specialists that manage problems with hormones and glands. In many cases endocrinologists manage patients with diabetes. In other cases, primary care providers (including internists and family practice specialists), treat type 2 diabetes.
How Is Type 2 Diabetes Diagnosed?
A fasting blood glucose measurement (fasting blood sugar test) is the preferred way to diagnose diabetes.
- A sample of blood is analyzed after a period of at least 8 hours of fasting. Typically these measurements are taken in the morning prior to breakfast. Normal values for fasting glucose are less than 100 mg/dl.
- Having fasting blood glucose levels of 126 mg/dl or greater on two or more tests on different days confirms the presence of diabetes.
- A random (non-fasting) blood glucose test can also be used to diagnose diabetes. A non-fasting blood glucose level of 200 mg/dl or higher indicates diabetes.
Other tests may also be performed such as:
- The oral glucose tolerance test (OGTT) involves a series of blood glucose measurements taken at intervals after consumption of a sugary solution. This test is no longer commonly used to diagnose type 2 diabetes, but it is often used to establish a diagnosis of gestational diabetes.
- The hemoglobin A1c (HbA1c, glycated hemoglobin) test is a blood test that measures hemoglobin that is bound to blood sugar. This test is indicative of the level of blood glucose over the past 3 months and is often measured in people with diabetes to determine the extent of disease control. An HbA1c level of 6.5% or higher is indicative of diabetes.
What Is the Treatment for Type 2 Diabetes?
The goal (and essential parts) of a treatment plan for type 2 diabetes is to
- maintain blood glucose levels under control to prevent complications of the disease,
- maintain a healthy weight, and
- get regular physical activity.
In some people, weight loss combined with physical activity is sufficient to control blood sugar levels. Other people will require medications for optimum control of their diabetes. The next sections of this article will discuss medications available to treat type 2 diabetes and a well-balanced diabetes diet.
Is There a Type 2 Diabetes Diet?
A healthy eating plan is an essential part of any diabetes treatment plan, but there is no one recommended "diabetic diet" for everyone. An individual nutrition plan will depend on many things, including underlying health and level of physical activity, the types of medication(s) being taken, and personal preference. Most people with type 2 diabetes find that having a fairly regular schedule for meals and snacks is helpful. Eating a variety of foods and watching portion sizes is also recommended.
Examples of meal planning tools that some people with type 2 diabetes like to use include
- the plate method,
- carbohydrate counting, or the
- glycemic index.
The Plate Method Diet Tool for Type 2 Diabetes
The plate method for meal planning assumes that half of one's plate will be filled with non-starchy vegetables like
- carrots, or
The remaining half of the plate is divided into three sections.
1. One of these three smaller sections should contain protein, such as
- lean pork or beef,
- tofu, or
2. Another small section is devoted to grains and/or starchy foods like
- cooked cereal, or
- whole-grain breads.
3. A serving or fruit or dairy can occupy the remaining small section.
Carbohydrate Counting and the Glycemic Method for Type 2 Diabetes
Carbohydrate counting is a meal planning technique is based on an allowed maximum carbohydrate count for each meal, and choosing your foods to fit within this limit. The amount of carbohydrates a person can consume with each meal and have good control of blood sugar will vary among individuals, depending on what medications taken and activity level.
The glycemic index method for type 2 diabetes
The glycemic index method balances food intake according to the particular glycemic index of the carbohydrate foods you eat. The glycemic index of a food reflects the glycemic response, or conversion to glucose, in the body. Glycemic Index uses a scale of 0 to 100, with higher values corresponding to foods that cause the most rapid rise in blood sugar. Pure glucose, for example, is the reference point and is given a Glycemic Index (GI) of 100. This method of meal planning involves choosing foods that have a low- or medium glycemic index instead of foods with a high glycemic index.
Carbohydrates with a high glycemic index that raise blood sugar levels quickly are
- white bread,
- russet potatoes, and
- corn flakes.
Low glycemic index carbohydrates include
- sweet potatoes,
- 100% stone-ground whole wheat bread,
- pasta, and
Will Exercise Help Control My Diabetes?
Regular physical activity can help control type diabetes and lower blood sugar levels. It also helps with weight control and weight loss. Exercise has other health benefits including
- decreasing the risk of cardiovascular disease,
- improving energy level, and
- helping to manage stress and control mood swings.
You should talk with your diabetes care team to help you determine the appropriate level and extent of physical activity, particularly if you have not been leading an active lifestyle.
What Medications Treat Type 2 Diabetes?
There are many different types of medications that treat type 2 diabetes. These drugs have different mechanisms of action, with the common goal of reducing and controlling blood sugar levels. In particular, diabetes medications may increase insulin output by the pancreas, increase sensitivity of cells to insulin, decrease the amount of glucose released from the liver, decrease the absorption of carbohydrates from the intestine, inhibit the absorption of glucose by the kidneys, or slow emptying of the stomach, thereby delaying absorption of nutrients in the small intestine.
Medications to treat type 2 diabetes are often used in combination and are only one part of a diabetes management program. Healthy eating and regular exercise are other basic components of the ideal diabetes management plan.
Types of medications for type 2 diabetes include:
- Alpha-glucosidase inhibitors
- Amylin mimetics
- Biguanides (metformin [Glucophage])
- DPP IV inhibitors
- GLP-1 analogs
- SGL T2 inhibitors
Each of these groups will be briefly described, along with some common examples of drugs in the particular class. All are taken orally except for certain injectable medications (insulin, amylin mimetics, GLP-1 analogs).
Amylin mimetics, thiazolidinediones, biguanides, and DDP IV inhibitors
Amylin mimetics, thiazolidinediones
Amylin mimetics include the medication pramlintide (Symlin). This drug is a
synthetic analog of human amylin, a hormone synthesized by the pancreas that
helps control glucose after meals. Like insulin, amylin is absent or deficient
people with diabetes. Pramlintide is given by injection prior to meals in people
who are taking insulin for type 1 or type 2 diabetes.
Thiazolidinediones work to lower blood sugar levels by increasing sensitivity
of muscle and fat cells to insulin. Drugs of this class tend to
improve cholesterol patterns in people with type 2 diabetes. Examples of
generation of this drug class, troglitazone (Regulin), was discontinued due to
its association with liver damage. Rosiglitazone (Avandia) has been associated
with an increased risk of heart attack and stroke, and the US FDA has imposed restrictions on its use. These drugs
should not be used in people with heart failure or liver disease.
Biguanides are a class of drugs that have been used for many years. Metformin
(Glucophage) belongs to this class of drugs and works by decreasing glucose
production by the liver. Earlier biguanide drugs could have serious side
effects, but metformin has been used safely since 1994 for the treatment of type
2 diabetes. Metformin can benefit overweight patients in that it often
DPP IV inhibitors
DPP-4 inhibitors are inhibitors of the enzyme dipeptidyl peptidase 4, which
breaks down GLP-1 (see below). This means that naturally-occurring GLP-1 has a
greater effect, leading to decreased stomach emptying and decreased production
of glucose by the liver. Examples of DPP-4 inhibitors are
GLP-1 analogs, meglitinides, and alpha-glucosidase inhibitors
GLP-1 analogs are also known as glucagon-like peptide-1 agonists or incretin
mimetics. They work by slowing stomach emptying and slowing the release of
glucose from the liver. Examples are
- exenatide extended
- dulaglutide (Trulicity), and
- albiglutide (Tanzeum).
These are given by injection and are used with other
diabetes medications like metformin and the sulfonylureas. GLP-1 analogs
stimulate the release of insulin from the pancreas. These drugs may promote
weight loss and are associated with a low risk of hypoglycemia
(low blood sugar).
Meglitinides also act by stimulating insulin release by the pancreas. Unlike
the sulfonylureas, meglitinides are very short-acting, having peak effects
within an hour. They are often taken up to 3 times a day before meals. Examples
of meglitinide are
Alpha-glucosidase inhibitors act by slowing down the digestion of complex
carbohydrates, reducing the impact of carbohydrate consumption on blood sugar.
Examples of alpha-glucosidase inhibitor drugs are
- carbose (Precose), and
They are taken with the first bite of food at mealtimes.
Sulfonylureas, SGL2 inhibitors, and insulin
Sulfonylureas are a class of drugs designed to increase insulin output by the
pancreas. Older sulfonylurea medications included
(Diabinese) and tolbutamide, which were abandoned due to a higher risk of
cardiovascular events in those taking the drugs. Examples of newer sulfonylurea
One potential risk of these drugs is that they very
rapidly lower blood sugar, potentially leading to abnormally low blood sugar (hypoglycemia).
SGL2 inhibitors are a relatively new class of medications. These are a class
of drugs known as sodium-glucose co-transporter 2 (SGLT2) inhibitors. SGLT2
inhibitors work by blocking the kidneys' reabsorption of glucose. This causes
more glucose to be excreted in the urine. Examples of SGL2 inhibitors include
- empagliflozine (Jardiance), and
These drugs also may promote weight loss.
Insulin is the hallmark of therapy for type 1 diabetes, but it can also be
used for patients with type 2 diabetes. Many different preparations of insulin
are available, with differences in the time required to take effect and the
duration of action. Insulin is often considered for treatment of type 2 diabetes
when the condition cannot be controlled by diet, weight loss, exercise, and oral
Can Type 2 Diabetes be Prevented?
While some risk factors for type 2 diabetes such as genetics and ethnicity cannot be controlled, other risk factors can be minimized with lifestyle modification. For example, it has been shown that in people with prediabetes or people at an increased risk for type 2 diabetes, even modest amounts of weight loss and physical activity can prevent or delay the onset of diabetes. Losing just 5%-7% of total body weight through 30 minutes of physical activity 5 days per week combined with healthier eating showed that it is possible to delay or prevent diabetes. Other studies have shown that reducing consumption of sugary drinks can delay or prevent type 2 diabetes. Drinking 1-2 cans of sugary drinks per day increased the risk of diabetes by 26% compared with people who did not consume sugared beverages. Eating plenty of fiber and whole grains can help maintain stable blood sugar levels and even reduce the risk of getting diabetes.
For some people at very high risk for developing diabetes (who have prediabetes and other risk factors), medications are recommended to delay the development of type 2 diabetes.
What Is the Prognosis for a Person with Type 2 Diabetes?
Type 2 diabetes can be managed with lifestyle modifications and can require medications. Maintaining good control of blood sugar levels can help prevent or delay many of the known complications of diabetes.
Long-term complications of diabetes include:
- Cardiovascular disease, including heart attack, stroke, peripheral vascular disease leading to pain in the lower legs (claudication), poor circulation
- Nerve damage, that often results in pain, numbness, or burning in the extremities (known as diabetic neuropathy)
- Eye problems, including damage to the retina of the eye due to circulatory problems (diabetic retinopathy), that can lead to loss of vision, cataracts, and glaucoma
- Kidney damage that can lead to kidney failure
- Erectile dysfunction in men, due to both nerve damage and circulatory problems
- Skin infections and poor wound healing
- In addition to optimal control of blood glucose levels and following a diabetes management plan, lowering blood pressure can help prevent the development of kidney disease and other complications.
Reviewed on 11/17/2017
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US Centers for Disease Control and Prevention. Preventing Diabetes.
Updated Sep 30, 2015.
National Institute of Diabetes and Digestive and Kidney Diseases.
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Khardori, R. MD. et al. "Type 2 Diabetes Mellitus." Medscape. Updated
Oct 08, 2015