Diabetes mellitus type 2

Type 2 diabetes, once called non-insulin-dependent diabetes, is the most common form of diabetes, affecting 90% to 95% of the 26 million Americans with diabetes.

This is also called "adult onset" diabetes, since it typically develops after age 35. However, a growing number of younger people are now developing type 2 diabetes.

People with type 2 are able to produce some of their own insulin. Often, it's not enough. And sometimes, the insulin will try to serve as the "key" to open the body's cells, to allow the glucose to enter. But the key won't work. The cells won't open. This is called insulin resistance.

Often, type 2 is tied to people who are overweight, with a sedentary lifestyle.

Essential update: FDA approves once-daily two-drug combination for type 2 diabetes The FDA has approved a once-daily combination tablet of the sodium glucose cotransporter - 2 inhibitor dapagliflozin and extended-release metformin for the treatment of adults with type 2 diabetes. The combination pill is available in several different doses and is indicated for use as an adjunct to diet and exercise in adults. The pill should be taken in the morning with food and the dosage increased gradually. Approval was based on four phase III studies that demonstrated efficacy and safety of each medicine individually in treatment-na?ve patients and those inadequately controlled on metformin alone.

Treatment focuses on diet and exercise. If blood sugar levels are still high, oral medications are used to help the body use its own insulin more efficiently. In some cases, insulin injections are necessary.

What Is Type 2 Diabetes?

Unlike people with type 1 diabetes, the bodies of people with type 2 diabetes make insulin. But either their pancreas does not make enough insulin or the body cannot use the insulin well enough. This is called insulin resistance. When there isn't enough insulin or the insulin is not used as it should be, glucose (sugar) can't get into the body's cells. When glucose builds up in the blood instead of going into cells, the body's cells are not able to function properly. Other problems associated with the buildup of glucose in the blood include:

  • Damage to the body. Over time, the high glucose levels in the blood can damage the nerves and small blood vessels of the eyes, kidneys, and heart and lead to atherosclerosis, or hardening of the arteries that can cause heart attack and stroke.
  • Dehydration. The buildup of sugar in the blood can cause an increase in urination, causing dehydration.
  • Diabetic coma (hyperosmolar nonketotic diabetic coma). When a person with type 2 diabetes becomes very ill or severely dehydrated and is not able to drink enough fluids to make up for the fluid losses, they may develop this life-threatening complication.


Diagnostic criteria by the American Diabetes Association (ADA) include the following[2] :

  • A fasting plasma glucose (FPG) level of 126 mg/dL (7.0 mmol/L) or higher, or
  • A 2-hour plasma glucose level of 200 mg/dL (11.1 mmol/L) or higher during a 75-g oral glucose tolerance test (OGTT), or
  • A random plasma glucose of 200 mg/dL (11.1 mmol/L) or higher in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis


Diabetes has been affecting lives for thousands of years. An ailment suspected to be diabetes was recognized by the Egyptians in manuscripts dating to 1550 BCE. According to The National Medical Journal of India, ancient Indians (circa 600 BCE) were well aware of the condition. They tested for diabetes-which they called "sweet urine disease"-by determining if ants were attracted to a person's urine.

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    In Greek, "diabetes" means "to pass through." Greek physicians named the disorder for its top symptom: the excessive passing of urine through the body's system.

    Historical documents show that Greek, Indian, Persian, Chinese, Japanese, and Korean doctors were aware of the condition, but none could determine its cause. In earlier times, a diagnosis of diabetes was likely a death sentence.

    Causes of Type 2 Diabetes

    Diabetes is a number of diseases that involve problems with the hormone insulin. While not everyone with type 2 diabetes is overweight, obesity and lack of physical activity are two of the most common causes of this form of diabetes. It is also responsible for nearly 95% of diabetes cases in the United States, according to the CDC.

    This article will give you a better understanding of the causes of type 2 diabetes, what happens in the body when type 2 diabetes occurs, and specific health problems that increase the risk of type 2 diabetes. Each section links to more in-depth information on that topic.

    In a healthy person, the pancreas (an organ behind the stomach) releases insulin to help the body store and use the sugar from the food you eat. Diabetes happens when one of the following occurs:

    • When the pancreas does not produce any insulin.
    • When the pancreas produces very little insulin.
    • When the body does not respond appropriately to insulin, a condition called "insulin resistance."

    Unlike people with type 1 diabetes, people with type 2 diabetes produce insulin; however, the insulin their pancreas secretes is either not enough or the body is unable to recognize the insulin and use it properly (insulin resistance). When there isn't enough insulin or the insulin is not used as it should be, glucose (sugar) can't get into the body's cells and builds up in the bloodstream instead. When glucose builds up in the blood instead of going into cells, it causes damage in multiple areas of the body. Also, since cells aren't getting the glucose they need, they can't function properly.

    The Role of Insulin in the Cause of Type 2 Diabetes

    To understand why insulin is important, it helps to know more about how the body uses food for energy. Your body is made up of millions of cells. To make energy, these cells need food in a very simple form. When you eat or drink, much of the food is broken down into a simple sugar called "glucose." Then, glucose is transported through the bloodstream to these cells where it can be used to provide the energy the body needs for daily activities.

    Whether a hemoglobin A1c (HbA1c) level of 6.5% or higher should be a primary diagnostic criterion or an optional criterion remains a point of controversy.

    Indications for diabetes screening in asymptomatic adults includes the following[3, 4] :

    • Sustained blood pressure >135/80 mm Hg
    • Overweight and 1 or more other risk factors for diabetes (eg, first-degree relative with diabetes, BP >140/90 mm Hg, and HDL < 35 mg/dL and/or triglyceride level >250 mg/dL)
    • ADA recommends screening at age 45 years in the absence of the above criteria

    Exams and Tests

    Your doctor may suspect that you have diabetes if your blood sugar level is higher than 200 mg/dL. To confirm the diagnosis, one or more of the following tests must be done.

    Diabetes blood tests:

    • Fasting blood glucose level. Diabetes is diagnosed if it is higher than 126 mg/dL two different times.
    • Hemoglobin A1c (A1C) test. Diabetes is diagnosed if the test result is 6.5% or higher.
    • Oral glucose tolerance test. Diabetes is diagnosed if the glucose level is higher than 200 mg/dL 2 hours after drinking a special sugar drink.

    Diabetes screening is recommended for:

    • Overweight children who have other risk factors for diabetes, starting at age 10 and repeated every 2 years
    • Overweight adults (BMI of 25 or higher) who have other risk factors
    • Adults starting at age 45 every 3 years, or at a younger age if the person has risk factors

    If you have been diagnosed with type 2 diabetes, you need to work closely with your doctor. You will likely need to see your doctor every 3 months. At these visits, you can expect your doctor to:

    • Check your blood pressure
    • Check the skin and bones on your feet and legs
    • Check if your feet are becoming numb
    • Examine the back part of the eye with a special lighted instrument

    The following tests will help you and your doctor monitor your diabetes and prevent problems.

    • Check the skin and bones on your feet and legs.
    • Check if your feet are getting numb (diabetic nerve disease).
    • Have your blood pressure checked at least once a year (blood pressure goals should be 140/80 mmHg or lower).
    • Have your A1C test every 6 months if your diabetes is well controlled. Have the test every 3 months if your diabetes is not well controlled.
    • Have your cholesterol and triglyceride levels checked yearly.
    • Get tests once a year to make sure your kidneys are working well (microalbuminuria and serum creatinine).
    • Visit your eye doctor at least once a year, or more often if you have signs of diabetic eye disease.
    • See the dentist every 6 months for a thorough dental cleaning and exam. Make sure your dentist and hygienist know that you have diabetes.

    Type 2 Diabetes Diet Tips

    It's no secret that diet is essential to managing type 2 diabetes symptoms. While there is no cure-all diet that is perfect for everyone, dietary choices are important in keeping your blood sugar level in the safe range.

    The Basics of Blood Sugar Control

    Type 2 diabetes is a condition in which the body doesn't make enough insulin. This can cause high blood sugar and symptoms such as:

    • fatigue
    • blurred vision
    • increased appetite
    • excessive thirst
    • excessive urination

    The normal blood sugar range for diabetics, as determined by the American Diabetes Association, is between 70 and 130 mg/dL before meals and less than 180 mg/dL a few hours after you began eating. You can use a blood sugar monitor to check your blood glucose levels and adjust your diet or medication accordingly.

    Low-Sugar Diet

    When someone with diabetes has low blood sugar (hypoglycemia), a spoonful of sugar or honey can help raise glucose levels. However, sugar is often considered the nemesis of diabetes because of how quickly it can spike blood glucose levels.

    If you have diabetes, you should closely monitor your sugar consumption - especially refined sugar and other forms of the simple carbohydrates. In addition to low-sugar foods, you should also eat low-fat foods and a well-balanced diet.

    Low-Fat Diet

    Foods that are high in sodium, saturated fats, cholesterol, and trans fat can elevate your risk for heart disease and stroke. However, that doesn't mean that you have to avoid all fats. Foods rich in good fats-monounsaturated and polyunsaturated fat - can help lower cholesterol levels, according to the Harvard School of Public Health.

    Try replacing the meat on your plate with omega-3 fatty acid-rich cold-water fish such as salmon, mackerel, and herring. Olive oil, avocado, and nuts are also good sources of this nutrient.

    Foods to Avoid:

    • red meat
    • bacon
    • processed foods
    • high-fat dairy products like cheese

    Fruits and Vegetables

    Balancing carbohydrates, fats, and sugars is integral to a diabetes-friendly diet. While processed and refined carbs are bad for you, whole grains and dietary fiber (good carbs) are beneficial in many ways. Whole grains are rich in fiber and beneficial vitamins and minerals. Dietary fiber helps with digestive health, and helps you feel more satisfied after eating.

    Type 2 Diabetes Risk Factors

    • Diabetes runs in your family. If you have a parent, brother, or sister with diabetes, your chances of getting it rise. But you can take action - through everyday lifestyle habits, like exercise and healthy eating - to lower your odds of following in their footsteps.
    • You have prediabetes. That means your blood sugar level is above normal but not in the diabetes range. You can stop prediabetes from becoming diabetes by getting more active, losing extra weight, and in some cases, taking the prescription drug metformin.
    • You're not physically active. It's never too late to change that! Check in with your doctor first, so you know what's safe for you to do.
    • You're overweight, especially around your waist. Not everyone with type 2 diabetes is overweight, but extra pounds make it more likely. Belly fat seems to be particularly risky.
    • You've had heart disease.
    • You have high blood pressure.
    • Your "good" cholesterol level is low. It's too low if it's less than 35 mg/dL (milligrams per deciliter).
    • Your triglyceride level is high. It's too high if it's over 250 mg/dL.
    • You've had diabetes during pregnancy before. That condition (called gestational diabetes) or delivering a baby over 9 pounds can make a woman more likely to get type 2 diabetes.
    • You're a woman who has PCOS (polycystic ovary syndrome).
    • You're 45 or older. The chance of getting type 2 diabetes rises with age. But diabetes is not a normal part of aging.
    • You are Hispanic, African-American, Native American, or Asian American. Diabetes is more common among these groups of people.
    • Talk with your doctor to get a better sense of your risk for getting type 2 diabetes - and to make a plan to lower your risk as much as possible.

    When to Eat

    If you have diabetes, you should eat smaller meals throughout the day to avoid unnecessary spikes in your blood glucose level. However, your body requires more sugars and carbohydrates during exercise, so eat before and after a workout.

    Your age, weight, height, level of exercise, and other factors also affect your diet. Monitor and record your blood glucose level in response to food and create your own personal diabetes diet with the help of your doctor or dietitian.

    Type 2 Diabetes in Children

    More and more children are being diagnosed with type 2 diabetes. Find out about type 2 diabetes symptoms in children, the diagnosis, and the treatment of type 2 diabetes in childhood. If your child is at risk for childhood diabetes, it's important to learn specific self-care tips to help prevent diabetes.

    Who Gets Type 2 Diabetes?

    Anyone can get type 2 diabetes. But those at highest risk for the disease are those who:

    • Are over 45
    • Are obese or overweight
    • Have had gestational diabetes
    • Have family members who have type 2 diabetes
    • Have prediabetes
    • Don't exercise
    • Have low HDL cholesterol or high triglycerides
    • Have high blood pressure
    • Are members of certain racial or ethnic groups including:
    • African Americans
    • Latinos
    • Native Americans
    • Asian Americans/Pacific Islanders

    Risk Factors for Type 2 Diabetes in Children

    The following risk factors are associated with an increased risk of type 2 diabetes in children:

    • Being overweight
    • Family history of diabetes
    • Female gender
    • Specific ethnic groups (American Indian, African-American, Asian, or Hispanic/Latino)
    • Other problems with insulin resistance (most people with type 2 diabetes in childhood are diagnosed at the start of puberty, a developmental stage where there's increased resistance)

    The single greatest risk factor for type 2 diabetes in children is excess weight. In the U.S., nearly one out of every five children is considered to be overweight. Once a child is overweight, chances are more than doubled that the child will develop diabetes. One or more of these factors may contribute to excess weight or obesity:

    • Unhealthy eating patterns
    • Lack of physical activity
    • An inherited tendency
    • Rarely, a hormone problem or other medical condition
    • In addition, as with adults, the risk of type 2 diabetes in children appears to be associated with excess abdominal weight. This obesity pattern increases the chance of insulin resistance and the risk of type 2 diabetes.