Type 2 Diabetes

Non-insulin Dependent Diabetes Mellitus; NIDDM; Adult-Onset Diabetes Mellitus; Diabetes Mellitus Type 2; "Stable" Diabetes; Insulin-Resistant Diabetes; Diabetes, Type 2) 
by Debra Wood, RN

En Español (Spanish Version) More InDepth Information on This Condition

* Definition  

Type 2 diabetes is when the body is resistant to high insulin levels. Insulin is a hormone made by the pancreas. Insulin helps your body convert food into energy. Without insulin, glucose (sugar) from the food you eat cannot enter cells. This causes glucose to build up in the blood. Meanwhile, your body tissues are starved for energy. However, in type 2 diabetes, there is plenty of insulin but the cells are resistant to its action.
Long-term, high blood sugar levels can damage the kidneys, eyes, nerves, and other tissues.

The Pancreas


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* Causes  

Two conditions contribute to type 2 diabetes:

  • Insulin resistance related to excess body fat (The body is unable to use the insulin it makes.)
  • Body's failure to make an adequate amount of insulin
* Risk Factors  

These factors increase your chance of developing type 2 diabetes. Tell your doctor if you have these risk factors:

  • Age: 40 or older
  • Sex: more common in older women than men
  • Obesity or being overweight (especially excess weight in the upper body and abdomen)
  • Lack of physical activity
  • Family members with type 2 diabetes
  • History of gestational diabetes
  • History of impaired glucose tolerance
  • Race: African American, Hispanic, Native American, Asian American, or Pacific Islander
  • Endocrine disorders ( Cushing’s syndrome , hyperthyroidism , acromegaly , polycystic ovary syndrome , pheochromocytoma, glucagonoma)
  • Medications (pentamidine , nicotinic acid, glucocorticoids, thiazide)
  • Genetic factors

A study reported that having a high intake of certain foods (like red meat, low-fiber bread, eggs, and cheese) can put you at risk for diabetes.*11 Talk to your doctor about a diet that is right for you.

* Symptoms  

You may not have symptoms for years if you have type 2 diabetes. Symptoms may be due to either high blood sugar or diabetic complications. These symptoms may include:

  • Weight loss
  • Increased urination
  • Extreme thirst
  • Hunger
  • Fatigue
  • Blurry vision
  • Irritability
  • Frequent or recurring infections
  • Poor wound healing
  • Angina
  • Painful leg cramps when walking
  • Numbness or tingling in the hands or feet
  • In women: frequent vaginal yeast infections
  • Problems with gums
  • Itching
  • Impotence
* Diagnosis  

The doctor will ask about your symptoms and medical and family history, and perform a physical exam.

Diagnosis is based on the results of blood tests and other criteria, including:

  • Symptoms of diabetes and a random blood test revealing a blood sugar level greater than or equal to 200 milligrams per deciliter of blood (mg/dL) [11.1 millimole per liter (mmol/L)]
  • Blood sugar tests after you have not eaten for eight or more hours revealing blood sugar levels greater than or equal to 126 mg/dL (7.0 mmol/L) on two different days
  • A glucose tolerance test measuring blood sugar two hours after you consume glucose with a measurement greater than or equal to 200 mg/dL (11.1 mmol/L)
* Treatment  

Diabetes treatment aims to maintain blood sugar at levels as close to normal as possible. Regular medical care is important for preventing or delaying complications.

Diet   Weight Loss  

If you are overweight, talk to your doctor about a reasonable weight goal and a safe diet program.

Group education may help people recently diagnosed with type 2 diabetes reach their goals in losing weight and quitting smoking. * 8 This is important because losing weight helps your body respond better to insulin. Also, quitting smoking can decrease your chance of getting many diseases, including heart disease, which is common in people with diabetes.


Physical activity helps the body use blood sugar. It will also help you reach and maintain a healthy weight, and lower the levels of fat in your blood. Follow your doctor's advice for activity levels and restrictions. Exercise was found to improve blood sugar control in patients with type 2 diabetes.* 2 Also, patients who received brief counseling during their regular doctor's appointments didn't have a difference in weight loss, but did have an increase in physical activity. * 9 Exercising more can help you improve glucose control and reduce your risk for heart disease.

Oral Medication  

Medications taken by mouth may be used to lower blood sugar:

  • Drugs that prompt the cells in the pancreas to make more insulin (eg, sulfonylureas [ glyburide , tolazamide] )
  • Insulin sensitizers—a class of drugs that help the body better use insulin (eg, rosiglitazone and pioglitazone )
  • Starch blockers—a class of drugs (eg, acarbose and miglitol ) that lessen glucose absorption into the bloodstream
  • Drugs that reduce the production of glucose by the liver (eg, metformin )
  • Amylin analogues (eg, pramlintide )
  • Dipeptidyl peptidase IV (DDPP-4) inhibitor (eg, sitagliptin )
  • Incretin-mimetic (eg, exenatide )

Two studies show the potential of increased harm when using the medications rosiglitazone or gliclazide to reach intensive blood sugar goals (hemoglobin A1C <6.5%). * 3,6,7,10


Insulin by injection supplement the insulin made by the body. Insulin therapy is needed when blood sugar levels are not kept low enough with diet, exercise, and medications.

Blood Sugar Testing  

Checking blood sugar levels during the day helps you keep track of the amount of glucose in your blood. This also determines if the dosage or type of antidiabetic treatment needs to be adjusted. Testing is easy with a blood glucose monitor. Keeping track of blood glucose levels is important if you take insulin.

However, many patients with type 2 diabetes can use another test called glycosylated hemoglobin or hemoglobin A1c (HbA1c). This is done in the doctor's office. Unlike blood sugar levels, HbA1c has the advantage of measuring average blood glucose levels over the previous three-month period. This shows the effectiveness of diabetes management over the long-term. Doctors advise that most diabetics keep their HbA1c levels below 7%.

A study suggests that regular blood sugar testing may not be needed in patients with type 2 diabetes whose condition is under reasonably good control without insulin. * 4 However, talk with your doctor before stopping blood sugar monitoring.

Alternative Therapies  

Researchers studied vitamin E supplementation in a particular group of patients—those with type 2 diabetes mellitus and a certain genotype (called Haptoglobin 2-2). Vitamin E was associated with a decrease in the rates of cardiovascular events. *5

* Prevention  

Regular physical activity and maintaining a healthy weight can reduce your chance of developing type 2 diabetes. In a trial of patients who were overweight and had prediabetes, lifestyle changes reduced the incidence of diabetes for up to seven years. * 1

Lifestyle changes seem to be more effective than medications in those with glucose intolerance. But ask your doctor if taking a drug, such as metformin or rosiglitazone, may reduce your risk of getting type 2 diabetes.

Last reviewed March 2008 by David Juan, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Copyright © 2009 EBSCO Publishing. All rights reserved.

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