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Type 2 Diabetes
(Diabetes Mellitus Type 2; Insulin-Resistant Diabetes; Diabetes, Type 2)
Glucose is a type of sugar. It comes from food, and is also created in the liver. Glucose travels through the body in the blood. It moves from the blood to cells with the help of a hormone called insulin. Once glucose is in those cells, it can be used for energy.
Diabetes is a condition that makes it difficult for the body to use glucose. This causes a buildup of glucose in the blood. It also means the body is not getting enough energy. Type 2 diabetes is one type of diabetes, and it is the most common.
Medication, lifestyle changes, and monitoring can help control blood glucose levels.
Type 2 diabetes is often caused by a combination of factors. One factor is that your body begins to make less insulin. A second factor is that your body becomes resistant to insulin. This means there is insulin in your body, but your body cannot use it effectively. Insulin resistance is often related to excess body fat.
Type 2 diabetes is more common in people who are aged 45 years and older. It is also common in younger people who are obese and belong to at-risk ethnic groups. Other factors that increase your chance for type 2 diabetes include:
- Prediabetes—impaired glucose tolerance and impaired fasting glucose
- Metabolic syndrome—a condition marked by elevated cholesterol, blood glucose, blood pressure, and central obesity
- Excess weight or obesity, especially central obesity
- Lack of exercise
- Poor diet—high intake of processed meats, fats, sugar-sweetened foods and beverages, and calories
- Family history of type 2 diabetes
- High blood pressure
- History of cardiovascular disease
- History of gestational diabetes, or having a baby that weighs over 9 pounds at birth
- Endocrine disorders, such as Cushing’s syndrome, hyperthyroidism, acromegaly, polycystic ovary syndrome, pheochromocytoma, or glucagonoma
- Conditions associated with insulin resistance, such as acanthosis nigricans
- Certain medications, such as glucocorticoids or thiazides
- Certain ethnic groups, such as African American, Hispanic, Native American, Hispanic American, Asian American, or Pacific Islander
You may have diabetes for years before you have symptoms. Symptoms caused by high blood sugar or include:
- Increased urination
- Extreme thirst
- Blurry vision
- Frequent or recurring infections
- Poor wound healing
- Numbness or tingling in the hands or feet
- Problems with gums
- Problems having an erection
The doctor will ask about your symptoms and medical history. You will also be asked about your family history. A physical exam will be done.
Diagnosis is based on the results of blood testing. American Diabetes Association (ADA) recommends diagnosis be made if you have one of the following:
- Symptoms of diabetes and a random blood test with a blood sugar level greater than or equal to 200 mg/dL (11.1 mmol/L)
- Fasting blood sugar test is done after you have not eaten for 8 or more hours—showing blood sugar levels greater than or equal to 126 mg/dL (7 mmol/L) on two different days
- Glucose tolerance test measures blood sugar 2 hours after you eat glucose—showing glucose levels greater than or equal to 200 mg/dL (11.1 mmol/L)
- HbA1c level of 6.5% or higher—indicates poor blood sugar control over the past 2-4 months
mg/dL = milligrams per deciliter of blood; mmol/L = millimole per liter of blood
Treatment aims to:
- Maintain blood sugar at levels as close to normal as possible
- Prevent or delay complications
- Control other conditions that you may have, like high blood pressure and high cholesterol
Food and drinks have a direct effect on your blood glucose level. Eating healthy meals can help you control your blood glucose. It will also help your overall health. Some basic tips include:
- Follow a balanced meal plan. It should include carbohydrates, proteins, and fats.
- Be aware of appropriate serving size. Measure your food to help understand ideal serving size.
- Do not skip meals. Plan your meals and snacks through the day. Having meals throughout the day can help avoid major changes in glucose levels.
- Eat plenty of vegetables and fiber.
- Limit the amount of fat (especially saturated and trans fats) in your foods.
- Eat moderate amounts of protein and low-fat dairy products.
- Carefully limit foods containing high concentrated sugar.
- Keep a record of your food intake. Share the record with your dietitian or doctor. This will help to create an effective meal plan.
If you are overweight, weight loss will help your body use insulin better. Talk to your doctor about a healthy weight goal. You and your doctor or dietitian can make a safe meal plan for you.
These options may help you lose weight:
- Use a portion control plate
- Use a prepared meal plan
- Eat a Mediterranean-style diet
Physical activity can:
- Make the body more sensitive to insulin
- Help you reach and maintain a healthy weight
- Lower the levels of fat in your blood
Aerobic exercise is any activity that increases your heart rate. Resistance training helps build muscle strength. Both types of exercise help to improve long-term glucose control. Regular exercise can also help reduce your risk of heart disease.
Talk to your doctor about an activity plan. Ask about any precautions you may need to take.
Certain medications will help to manage blood glucose levels.
Medication taken by mouth may include:
- Biguanides reduce the amount of glucose made by the body
- Sulfonylureas encourage the pancreas to make more insulin
- Insulin sensitizers to help the body use insulin better
- Starch blockers to decrease the amount of glucose absorbed into the blood
- Sodium-glucose co-transporter 2 (SGLT-2) inhibitors to increase glucose excretion in urine
- Bile acid binders
Some medications needs to be given by injection, such as:
- Incretin-mimetics stimulate the pancreas to produce insulin and decrease appetite, which can assist with weight loss
- Amylin analogs replace a protein of the pancreas that is low in people with type 2 diabetes
Insulin may be needed if:
- The body does not make enough of its own insulin
- Blood glucose levels cannot be controlled with lifestyle changes and medications
Insulin is given through injections. There is one short-acting inhaled insulin which may be available for select persons.
Blood Glucose Testing
You can check the level of glucose in your blood with a blood glucose meter. Checking your blood glucose levels during the day can help you stay on track. It will also help your doctor determine if your treatment is working. Keeping track of blood sugar levels is especially important if you take insulin.
Regular testing may not be needed if your diabetes is under control and you don't take insulin. Talk with your doctor before stopping blood sugar monitoring.
An HbA1c test may also be done at your doctor's office. This is a measure of blood glucose control over a long period of time. Doctors advise that most people keep their HbA1c levels below 7%. Your exact goal may be different. Keeping HbA1c in your goal range can help lower the chance of complications.
Depression can undermine your recovery and put you at risk for other complications. Feelings of sadness, hopelessness, and loss of interest in your favorite activities that stay with you for at least 2 weeks should prompt you to call your doctor. Depression is treatable. Your doctor may refer you to counseling to help you better manage your depression and diabetes.
Decreasing Risk of Complications
Over a long period of time, high blood glucose levels can damage vital organs. The kidneys, eyes, and nerves are most affected. Diabetes can also increase your risk of heart disease.
Maintaining goal blood glucose levels is the first step to lowering your risk of these complications. Other steps:
- Take good care of your feet. Be on the lookout for any sores or irritated areas. Keep your feet dry and clean.
- Have your eyes checked once a year.
- Don't smoke. If you do, look for programs or products that can help you quit.
- Keep track of your moods and be alert for persistent depressive symptoms.
- Plan medical visits as recommended.
To help reduce your chance of type 2 diabetes:
- Participate in regular physical activity
- Maintain a healthy weight
- Drink alcohol only in moderation (2 drinks per day for a man, and 1 drink per day for a woman)
Eat a well-balanced diet:
- Get enough fiber
- Avoid fatty foods
- Limit sugar intake
- Eat more green, leafy vegetables
- Eat whole fruits, especially apples, grapes, and blueberries
American Diabetes Association
National Diabetes Information Clearinghouse
Canadian Diabetes Association
Public Health Agency of Canada
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- Reviewer: Kim Carmichael, MD
- Review Date: 09/2015
- Update Date: 09/03/2015