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Type 2 Diabetes

(Diabetes Mellitus Type 2; Insulin-Resistant Diabetes; Diabetes, Type 2)

Definition

Diabetes happens when the body does not make enough insulin to move glucose from the blood to the cells. This causes glucose to build up in the blood instead of being used by the cells for energy. Type 2 is more common in adults.

Causes

Type 2 happens when the body becomes resistant to insulin or when the pancreas cannot make enough. This may be due to a person's genes and habits.

Risk Factors

Type 2 is more common in people with obesity and those over 45 years of age. People who are American Indian, Alaska natives, Black, and Hispanic are at higher risk. Some other common risks are:

Prediabetes—slightly high glucose levels
Metabolic syndrome—fat around the belly and high cholesterol, glucose, and blood pressure
Polycystic ovary syndrome
Past gestational diabetes or having a baby that weighs over 9 pounds at birth
Poor eating habits
Lack of exercise
Smoking
High blood pressure
Taking certain medicines, such as glucocorticoids or thiazides

Symptoms

Most people do not have problems right away. Others may have:

Urinating more often
Being very thirsty
Hunger
Blurry eyesight
Weight loss
Being very tired
Frequent infections

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done.

Diabetes is diagnosed with blood tests that check for high glucose levels. More than 1 test may be done.

These blood tests will also be done to find out whether it is type 1 or type 2:

Insulin level or C-peptide tests to see how much insulin is being made by the pancreas
Tests that look for antibodies that are working against the pancreas

Treatment

The goal is to keep glucose levels at close to normal levels. This can be done with:

Healthy Habits

Healthy habits can help manage type 2, such as:

Testing blood glucose levels often
Working with a dietitian to make a meal plan that will help keep blood glucose levels normal
Getting enough exercise
Reaching a healthy weight

Medicine

Some people may need medicine to lower insulin resistance. There are many types. Metformin is a common medicine that is given.

People who cannot manage type 2 with healthy habits and medicine may need insulin. It will replace the insulin hormone that their body does not make. It can be given by injection, inhaler, or by a pump that gives it in small amounts during the day.

Prevention

A person may not be able to lower the risk of diabetes. Healthy habits may help, such as exercising, staying at a healthy weight, and eating right.

RESOURCES

American Diabetes Association
http://www.diabetes.org

National Diabetes Information Clearinghouse
http://diabetes.niddk.nih.gov

CANADIAN RESOURCES

Canadian Diabetes Association
http://www.diabetes.ca

Public Health Agency of Canada
http://www.phac-aspc.gc.ca

References

American Association of Clinical Endocrinologists, American College of Endocrinology. Comprehensive Type 2 Diabetes Management Algorithm 2017. Endocr Pract. 2017 Feb;23(2):207-238.

American Diabetes Association Classification and Diagnosis of Diabetes of Diabetes Mellitus. Diabetes Care. 2015 Jan;38 Suppl:S8-S16.

American Diabetes Association. Standards of medical care in diabetes. Diabetes Care. 2019 Jan; 42 (Suppl 1):S1-S193,

Diabetes mellitus type 2 in adults. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/diabetes-mellitus-type-2-in-adults. Updated February 14, 2019. Accessed November 1, 2019.

Diabetes mellitus type 2 in children and adolescents. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/diabetes-mellitus-type-2-in-children-and-adolescents. Updated May 7, 2019. Accessed November 1, 2019.

Dietary considerations for patients with type 2 diabetes. EBSCO DynaMed website. Available at: https://www.dynamed.com/management/dietary-considerations-for-patients-with-type-2-diabetes. Updated March 11, 2019. Accessed November 1, 2019.

Symptoms & Causes of Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/symptoms-causes. Updated December 2016. Accessed November 1, 2019.

9/16/2014 DynaMed Systematic Literature Surveillance https://www.dynamed.com/prevention/diabetes-mellitus-type-2-prevention: Zhou D, Yu H, et al. Nut consumption in relation to cardiovascular disease risk and type 2 diabetes: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr. 2014;100(1):270-277.

12/14/2016 DynaMed Systematic Literature Surveillance https://www.dynamed.com/condition/risk-factors-for-diabetes-mellitus-type-2: Shen HN, Yang CC, et al. Risk of diabetes mellitus after first-attack acute pancreatitis: a national population-based study. Am J Gastroenterol. 2015;110(12):1698-1706.

10/1/2018 DynaMed Systematic Literature Surveillance https://www.dynamed.com/condition/risk-factors-for-diabetes-mellitus-type-2 : Mantovani A, Byrne CD, et al. Nonalcoholic fatty liver disease and risk of incident type 2 diabetes: a meta-analysis. Diabetes Care. 2018;41(2):372-382.

Revision Information

Reviewer: EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Review Date: 09/2019
Update Date: 07/28/2020

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This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

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