Get Diabetes Mellitus Type 2 essential facts below. View Videos or join the Diabetes Mellitus Type 2 discussion. Add Diabetes Mellitus Type 2 to your PopFlock.com topic list for future reference or share this resource on social media.
Diabetes Mellitus Type 2
Type of diabetes mellitus with high blood sugar and insulin resistance
Type 2 diabetes
Diabetes mellitus type 2; adult-onset diabetes; noninsulin-dependent diabetes mellitus (NIDDM)
Type 2 diabetes is largely preventable by staying a normal weight, exercising regularly, and eating properly. Treatment involves exercise and dietary changes. If blood sugar levels are not adequately lowered, the medication metformin is typically recommended. Many people may eventually also require insulin injections. In those on insulin, routinely checking blood sugar levels is advised; however, this may not be needed in those taking pills.Bariatric surgery often improves diabetes in those who are obese.
Rates of type 2 diabetes have increased markedly since 1960 in parallel with obesity. As of 2015 there were approximately 392 million people diagnosed with the disease compared to around 30 million in 1985. Typically it begins in middle or older age, although rates of type 2 diabetes are increasing in young people. Type 2 diabetes is associated with a ten-year-shorter life expectancy. Diabetes was one of the first diseases described. The importance of insulin in the disease was determined in the 1920s.
Signs and symptoms
Overview of the most significant symptoms of diabetes.
The development of type 2 diabetes is caused by a combination of lifestyle and genetic factors. While some of these factors are under personal control, such as diet and obesity, other factors are not, such as increasing age, female gender, and genetics. Obesity is more common in women than men in many parts of Africa. A lack of sleep has been linked to type 2 diabetes. This is believed to act through its effect on metabolism. The nutritional status of a mother during fetal development may also play a role, with one proposed mechanism being that of DNA methylation. The intestinal bacteria Prevotella copri and Bacteroides vulgatus have been connected with type 2 diabetes.
Lifestyle factors are important to the development of type 2 diabetes, including obesity and being overweight (defined by a body mass index of greater than 25), lack of physical activity, poor diet, stress, and urbanization. Excess body fat is associated with 30% of cases in those of Chinese and Japanese descent, 60-80% of cases in those of European and African descent, and 100% of cases in Pima Indians and Pacific Islanders. Among those who are not obese, a high waist-hip ratio is often present. Smoking appears to increase the risk of type 2 diabetes.
Most cases of diabetes involve many genes, with each being a small contributor to an increased probability of becoming a type 2 diabetic. The proportion of diabetes that is inherited is estimated at 72%. More than 36 genes and 80 single nucleotide polymorphisms (SNPs) had been found that contribute to the risk of type 2 diabetes. All of these genes together still only account for 10% of the total heritable component of the disease. The TCF7L2allele, for example, increases the risk of developing diabetes by 1.5 times and is the greatest risk of the common genetic variants. Most of the genes linked to diabetes are involved in pancreatic beta cell functions.
Type 2 diabetes is due to insufficient insulin production from beta cells in the setting of insulin resistance. Insulin resistance, which is the inability of cells to respond adequately to normal levels of insulin, occurs primarily within the muscles, liver, and fat tissue. In the liver, insulin normally suppresses glucose release. However, in the setting of insulin resistance, the liver inappropriately releases glucose into the blood. The proportion of insulin resistance versus beta cell dysfunction differs among individuals, with some having primarily insulin resistance and only a minor defect in insulin secretion and others with slight insulin resistance and primarily a lack of insulin secretion.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system. However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required.
A random blood sugar of greater than 11.1 mmol/l (200 mg/dl) in association with typical symptoms or a glycated hemoglobin (HbA1c) of >= 48 mmol/mol (>= 6.5 DCCT %) is another method of diagnosing diabetes. In 2009 an International Expert Committee that included representatives of the American Diabetes Association (ADA), the International Diabetes Federation (IDF), and the European Association for the Study of Diabetes (EASD) recommended that a threshold of >= 48 mmol/mol (>= 6.5 DCCT %) should be used to diagnose diabetes. This recommendation was adopted by the American Diabetes Association in 2010. Positive tests should be repeated unless the person presents with typical symptoms and blood sugars >11.1 mmol/l (>200 mg/dl).
Threshold for diagnosis of diabetes is based on the relationship between results of glucose tolerance tests, fasting glucose or HbA1c and complications such as retinal problems. A fasting or random blood sugar is preferred over the glucose tolerance test, as they are more convenient for people. HbA1c has the advantages that fasting is not required and results are more stable but has the disadvantage that the test is more costly than measurement of blood glucose. It is estimated that 20% of people with diabetes in the United States do not realize that they have the disease.
Type 2 diabetes is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. This is in contrast to type 1 diabetes in which there is an absolute insulin deficiency due to destruction of islet cells in the pancreas and gestational diabetes that is a new onset of high blood sugars associated with pregnancy. Type 1 and type 2 diabetes can typically be distinguished based on the presenting circumstances. If the diagnosis is in doubt antibody testing may be useful to confirm type 1 diabetes and C-peptide levels may be useful to confirm type 2 diabetes, with C-peptide levels normal or high in type 2 diabetes, but low in type 1 diabetes.
No major organization recommends universal screening for diabetes as there is no evidence that such a program improve outcomes. Screening is recommended by the United States Preventive Services Task Force (USPSTF) in adults without symptoms whose blood pressure is greater than 135/80 mmHg. For those whose blood pressure is less, the evidence is insufficient to recommend for or against screening. There is no evidence that it changes the risk of death in this group of people. They also recommend screening among those who are overweight and between the ages of 40 and 70.
Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise.[needs update] Intensive lifestyle measures may reduce the risk by over half. The benefit of exercise occurs regardless of the person's initial weight or subsequent weight loss. High levels of physical activity reduce the risk of diabetes by about 28%. Evidence for the benefit of dietary changes alone, however, is limited, with some evidence for a diet high in green leafy vegetables and some for limiting the intake of sugary drinks. There is an association between higher intake of sugar-sweetened fruit juice and diabetes, but no evidence of an association with 100% fruit juice. A 2019 review found evidence of benefit from dietary fiber.
In those with impaired glucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes. Lifestyle interventions are more effective than metformin. A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal. While low vitamin D levels are associated with an increased risk of diabetes, correcting the levels by supplementing vitamin D3 does not improve that risk.
Management of type 2 diabetes focuses on lifestyle interventions, lowering other cardiovascular risk factors, and maintaining blood glucose levels in the normal range. Self-monitoring of blood glucose for people with newly diagnosed type 2 diabetes may be used in combination with education, although the benefit of self-monitoring in those not using multi-dose insulin is questionable. In those who do not want to measure blood levels, measuring urine levels may be done. Managing other cardiovascular risk factors, such as hypertension, high cholesterol, and microalbuminuria, improves a person's life expectancy. Decreasing the systolic blood pressure to less than 140 mmHg is associated with a lower risk of death and better outcomes. Intensive blood pressure management (less than 130/80 mmHg) as opposed to standard blood pressure management (less than 140-160 mmHg systolic to 85-100 mmHg diastolic) results in a slight decrease in stroke risk but no effect on overall risk of death.
Intensive blood sugar lowering (HbA1c<6%) as opposed to standard blood sugar lowering (HbA1c of 7-7.9%) does not appear to change mortality. The goal of treatment is typically an HbA1c of 7 to 8% or a fasting glucose of less than 7.2 mmol/L (130 mg/dl); however these goals may be changed after professional clinical consultation, taking into account particular risks of hypoglycemia and life expectancy. Hypoglycemia is associated with adverse outcomes in older people with type 2 diabetes. Despite guidelines recommending that intensive blood sugar control be based on balancing immediate harms with long-term benefits, many people - for example people with a life expectancy of less than nine years who will not benefit, are over-treated.
It is recommended that all people with type 2 diabetes get regular eye examinations. There is weak evidence suggesting that treating gum disease by scaling and root planing may result in a small short-term improvement in blood sugar levels for people with diabetes. There is no evidence to suggest that this improvement in blood sugar levels is maintained longer than 4 months. There is also not enough evidence to determine if medications to treat gum disease are effective at lowering blood sugar levels.
A proper diet and exercise are the foundations of diabetic care, with a greater amount of exercise yielding better results. Exercise improves blood sugar control, decreases body fat content and decreases blood lipid levels, and these effects are evident even without weight loss.Aerobic exercise leads to a decrease in HbA1c and improved insulin sensitivity.Resistance training is also useful and the combination of both types of exercise may be most effective.
Vegetarian diets in general have been related to lower diabetes risk, but do not offer advantages compared with diets which allow moderate amounts of animal products. There is not enough evidence to suggest that cinnamon improves blood sugar levels in people with type 2 diabetes.
Culturally appropriate education may help people with type 2 diabetes control their blood sugar levels, for up to 24 months. If changes in lifestyle in those with mild diabetes has not resulted in improved blood sugars within six weeks, medications should then be considered. There is not enough evidence to determine if lifestyle interventions affect mortality in those who already have DM2.
As of 2015[update], there is insufficient data to recommend nonnutritive sweeteners, but note they may help reduce caloric intake.
Metformin 500mg tablets.
There are several classes of anti-diabetic medications available. Metformin is generally recommended as a first line treatment as there is some evidence that it decreases mortality; however, this conclusion is questioned. Metformin should not be used in those with severe kidney or liver problems.
Injections of insulin may either be added to oral medication or used alone. Most people do not initially need insulin. When it is used, a long-acting formulation is typically added at night, with oral medications being continued. Doses are then increased to effect (blood sugar levels being well controlled). When nightly insulin is insufficient, twice daily insulin may achieve better control. The long acting insulins glargine and detemir are equally safe and effective, and do not appear much better than neutral protamine Hagedorn (NPH) insulin, but as they are significantly more expensive, they are not cost effective as of 2010. In those who are pregnant, insulin is generally the treatment of choice.
Vitamin D supplementation to people with type 2 diabetes may improve markers of insulin resistance and HbA1c.
Weight loss surgery in those who are obese is an effective measure to treat diabetes. Many are able to maintain normal blood sugar levels with little or no medication following surgery and long-term mortality is decreased. There however is some short-term mortality risk of less than 1% from the surgery. The body mass index cutoffs for when surgery is appropriate are not yet clear. It is recommended that this option be considered in those who are unable to get both their weight and blood sugar under control.
Regional rates of diabetes using data from 195 countries in 2014
Rates of diabetes in 1985 were estimated at 30 million, increasing to 135 million in 1995 and 217 million in 2005. This increase is believed to be primarily due to the global population aging, a decrease in exercise, and increasing rates of obesity. The five countries with the greatest number of people with diabetes as of 2000 are India having 31.7 million, China 20.8 million, the United States 17.7 million, Indonesia 8.4 million, and Japan 6.8 million. It is recognized as a global epidemic by the World Health Organization.
Diabetes is one of the first diseases described with an Egyptian manuscript from c. 1500 BCE mentioning "too great emptying of the urine." The first described cases are believed to be of type 1 diabetes. Indian physicians around the same time identified the disease and classified it as madhumeha or honey urine noting that the urine would attract ants. The term "diabetes" or "to pass through" was first used in 230 BCE by the Greek Apollonius Of Memphis. The disease was rare during the time of the Roman empire with Galen commenting that he had only seen two cases during his career.
Type 1 and type 2 diabetes were identified as separate conditions for the first time by the Indian physicians Sushruta and Charaka in 400-500 AD with type 1 associated with youth and type 2 with being overweight. The term "mellitus" or "from honey" was added by the Briton John Rolle in the late 1700s to separate the condition from diabetes insipidus which is also associated with frequent urination. Effective treatment was not developed until the early part of the 20th century when the Canadians Frederick Banting and Charles Best discovered insulin in 1921 and 1922. This was followed by the development of the long acting NPH insulin in the 1940s.
In 1916, Elliot Joslin proposed that in people with diabetes, periods of fasting are helpful. Subsequent research has supported this, and weight loss is a first line treatment in type 2 diabetes.
^ abcMaruthur NM, Tseng E, Hutfless S, Wilson LM, Suarez-Cuervo C, Berger Z, Chu Y, Iyoha E, Segal JB, Bolen S (June 2016). "Diabetes Medications as Monotherapy or Metformin-Based Combination Therapy for Type 2 Diabetes: A Systematic Review and Meta-analysis". Annals of Internal Medicine. 164 (11): 740-51. doi:10.7326/M15-2650. PMID27088241.
^ abcdefghijklmnopqrsMelmed, Shlomo; Polonsky, Kenneth S.; Larsen, P. Reed; Kronenberg, Henry M., eds. (2011). Williams textbook of endocrinology (12th ed.). Philadelphia: Elsevier/Saunders. pp. 1371-1435. ISBN978-1-4377-0324-5.
^Saenz A, Fernandez-Esteban I, Mataix A, Ausejo M, Roque M, Moher D (July 2005). "Metformin monotherapy for type 2 diabetes mellitus". The Cochrane Database of Systematic Reviews (3): CD002966. doi:10.1002/14651858.CD002966.pub3. PMID16034881. (Retracted)
^Moscou, Susan (2013). "Getting the word out: advocacy, social marketing, and policy development and enforcement". In Truglio-Londrigan, Marie; Lewenson, Sandra B. (eds.). Public health nursing: practicing population-based care (2nd ed.). Burlington, MA: Jones & Bartlett Learning. p. 317. ISBN978-1-4496-4660-8. OCLC758391750.
^Akinpelu, Olubunmi V.; Mujica-Mota, Mario; Daniel, Sam J. (March 2014). "Is type 2 diabetes mellitus associated with alterations in hearing? A systematic review and meta-analysis". The Laryngoscope. 124 (3): 767-776. doi:10.1002/lary.24354. ISSN1531-4995. PMID23945844.
^Christian P, Stewart CP (March 2010). "Maternal micronutrient deficiency, fetal development, and the risk of chronic disease". The Journal of Nutrition. 140 (3): 437-45. doi:10.3945/jn.109.116327. PMID20071652.
^Abdullah A, Peeters A, de Courten M, Stoelwinder J (September 2010). "The magnitude of association between overweight and obesity and the risk of diabetes: a meta-analysis of prospective cohort studies". Diabetes Research and Clinical Practice. 89 (3): 309-19. doi:10.1016/j.diabres.2010.04.012. PMID20493574.
^Willemsen, Gonneke; Ward, Kirsten J.; Bell, Christopher G.; Christensen, Kaare; Bowden, Jocelyn; Dalgård, Christine; Harris, Jennifer R.; Kaprio, Jaakko; Lyle, Robert; Magnusson, Patrik K. E.; Mather, Karen A. (December 2015). "The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers: The Discordant Twin (DISCOTWIN) Consortium". Twin Research and Human Genetics: The Official Journal of the International Society for Twin Studies. 18 (6): 762-771. doi:10.1017/thg.2015.83. ISSN1832-4274. PMID26678054.
^Saad F, Gooren L (March 2009). "The role of testosterone in the metabolic syndrome: a review". The Journal of Steroid Biochemistry and Molecular Biology. 114 (1-2): 40-3. doi:10.1016/j.jsbmb.2008.12.022. PMID19444934.
^Nieto-Martínez, R; González-Rivas, JP; Medina-Inojosa, JR; Florez, H (22 November 2017). "Are Eating Disorders Risk Factors for Type 2 Diabetes? A Systematic Review and Meta-analysis". Current Diabetes Reports (Systematic review and meta-analysis). 17 (12): 138. doi:10.1007/s11892-017-0949-1. ISSN1539-0829. PMID29168047.
^Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Cotran, Ramzi S.; Robbins, Stanley L. (2005). Robbins and Cotran Pathologic Basis of Disease (7th ed.). Philadelphia, Pa.: Saunders. pp. 1194-95. ISBN978-0-7216-0187-8.
^ abSelph S, Dana T, Blazina I, Bougatsos C, Patel H, Chou R (June 2015). "Screening for type 2 diabetes mellitus: a systematic review for the U.S. Preventive Services Task Force". Annals of Internal Medicine. 162 (11): 765-76. doi:10.7326/M14-2221. PMID25867111.
^Siu AL (December 2015). "Screening for Abnormal Blood Glucose and Type 2 Diabetes Mellitus: U.S. Preventive Services Task Force Recommendation Statement". Annals of Internal Medicine. 163 (11): 861-8. doi:10.7326/M15-2345. PMID26501513.
^ abSchellenberg ES, Dryden DM, Vandermeer B, Ha C, Korownyk C (October 2013). "Lifestyle interventions for patients with and at risk for type 2 diabetes: a systematic review and meta-analysis". Annals of Internal Medicine. 159 (8): 543-51. doi:10.7326/0003-4819-159-8-201310150-00007. PMID24126648.
^Emdin CA, Rahimi K, Neal B, Callender T, Perkovic V, Patel A (February 2015). "Blood pressure lowering in type 2 diabetes: a systematic review and meta-analysis". JAMA. 313 (6): 603-15. doi:10.1001/jama.2014.18574. PMID25668264.
^McBrien K, Rabi DM, Campbell N, Barnieh L, Clement F, Hemmelgarn BR, Tonelli M, Leiter LA, Klarenbach SW, Manns BJ (September 2012). "Intensive and Standard Blood Pressure Targets in Patients With Type 2 Diabetes Mellitus: Systematic Review and Meta-analysis". Archives of Internal Medicine. 172 (17): 1296-303. doi:10.1001/archinternmed.2012.3147. PMID22868819.
^ abcdInzucchi SE, Bergenstal RM, Buse JB, Diamant M, Ferrannini E, Nauck M, Peters AL, Tsapas A, Wender R, Matthews DR (March 2015). "Management of hyperglycaemia in type 2 diabetes, 2015: a patient-centred approach. Update to a position statement of the American Diabetes Association and the European Association for the Study of Diabetes". Diabetologia. 58 (3): 429-42. doi:10.1007/s00125-014-3460-0. PMID25583541.
^Qaseem A, Wilt TJ, Kansagara D, Horwitch C, Barry MJ, Forciea MA (April 2018). "Hemoglobin A1c Targets for Glycemic Control With Pharmacologic Therapy for Nonpregnant Adults With Type 2 Diabetes Mellitus: A Guidance Statement Update From the American College of Physicians". Annals of Internal Medicine. 168 (8): 569-576. doi:10.7326/M17-0939. PMID29507945.
^Davis N, Forbes B, Wylie-Rosett J (June 2009). "Nutritional strategies in type 2 diabetes mellitus". The Mount Sinai Journal of Medicine, New York. 76 (3): 257-68. doi:10.1002/msj.20118. PMID19421969.
^Evert, A. B.; Boucher, J. L.; Cypress, M.; Dunbar, S. A.; Franz, M. J.; Mayer-Davis, E. J.; Neumiller, J. J.; Nwankwo, R.; Verdi, C. L.; Urbanski, P.; Yancy, W. S. (19 December 2013). "Nutrition Therapy Recommendations for the Management of Adults With Diabetes". Diabetes Care (Professional society guidelines). 37 (Supplement_1): S120-S143. doi:10.2337/dc14-S120. PMID24357208.
^Attridge M, Creamer J, Ramsden M, Cannings-John R, Hawthorne K (September 2014). "Culturally appropriate health education for people in ethnic minority groups with type 2 diabetes mellitus". The Cochrane Database of Systematic Reviews (9): CD006424. doi:10.1002/14651858.CD006424.pub3. PMID25188210.
^Palmer SC, Mavridis D, Nicolucci A, Johnson DW, Tonelli M, Craig JC, Maggo J, Gray V, De Berardis G, Ruospo M, Natale P, Saglimbene V, Badve SV, Cho Y, Nadeau-Fredette AC, Burke M, Faruque L, Lloyd A, Ahmad N, Liu Y, Tiv S, Wiebe N, Strippoli GF (July 2016). "Comparison of Clinical Outcomes and Adverse Events Associated With Glucose-Lowering Drugs in Patients With Type 2 Diabetes: A Meta-analysis". JAMA. 316 (3): 313-24. doi:10.1001/jama.2016.9400. PMID27434443.
^Chen X, Yang L, Zhai SD (December 2012). "Risk of cardiovascular disease and all-cause mortality among diabetic patients prescribed rosiglitazone or pioglitazone: a meta-analysis of retrospective cohort studies". Chinese Medical Journal. 125 (23): 4301-6. PMID23217404.
^ abCheng J, Zhang W, Zhang X, Han F, Li X, He X, Li Q, Chen J (May 2014). "Effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on all-cause mortality, cardiovascular deaths, and cardiovascular events in patients with diabetes mellitus: a meta-analysis". JAMA Internal Medicine. 174 (5): 773-85. doi:10.1001/jamainternmed.2014.348. PMID24687000.
^Waugh N, Cummins E, Royle P, Clar C, Marien M, Richter B, Philip S (July 2010). "Newer agents for blood glucose control in type 2 diabetes: systematic review and economic evaluation". Health Technology Assessment. 14 (36): 1-248. doi:10.3310/hta14360. PMID20646668.
^Mirhosseini N, Vatanparast H, Mazidi M, Kimball SM (September 2017). "The Effect of Improved Serum 25-Hydroxyvitamin D Status on Glycemic Control in Diabetic Patients: A Meta-Analysis". The Journal of Clinical Endocrinology and Metabolism. 102 (9): 3097-3110. doi:10.1210/jc.2017-01024. PMID28957454.
^Picot J, Jones J, Colquitt JL, Gospodarevskaya E, Loveman E, Baxter L, Clegg AJ (September 2009). "The clinical effectiveness and cost-effectiveness of bariatric (weight loss) surgery for obesity: a systematic review and economic evaluation". Health Technology Assessment. 13 (41): 1-190, 215-357, iii-iv. doi:10.3310/hta13410. hdl:10536/DRO/DU:30064294. PMID19726018.
^ abSchulman AP, del Genio F, Sinha N, Rubino F (September-October 2009). ""Metabolic" surgery for treatment of type 2 diabetes mellitus". Endocrine Practice. 15 (6): 624-31. doi:10.4158/EP09170.RAR. PMID19625245.
^Rubino F, Nathan DM, Eckel RH, Schauer PR, Alberti KG, Zimmet PZ, Del Prato S, Ji L, Sadikot SM, Herman WH, Amiel SA, Kaplan LM, Taroncher-Oldenburg G, Cummings DE (June 2016). "Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations". Diabetes Care. 39 (6): 861-77. doi:10.2337/dc16-0236. PMID27222544.
^Carulli L, Rondinella S, Lombardini S, Canedi I, Loria P, Carulli N (November 2005). "Review article: diabetes, genetics and ethnicity". Alimentary Pharmacology & Therapeutics. 22 Suppl 2: 16-9. doi:10.1111/j.1365-2036.2005.02588.x. PMID16225465.
^Wild S, Roglic G, Green A, Sicree R, King H (May 2004). "Global prevalence of diabetes: estimates for the year 2000 and projections for 2030". Diabetes Care. 27 (5): 1047-53. doi:10.2337/diacare.27.5.1047. PMID15111519.
^ abKoutroumpakis, E; Jozwik, B; Aguilar, D; Taegtmeyer, H (11 September 2019). "Strategies of Unloading the Failing Heart from Metabolic Stress". The American Journal of Medicine (Review). doi:10.1016/j.amjmed.2019.08.035. PMID31520618.