Overall, these studies suggest that tight glycemic control (HbA1c < 7% or lower) is valuable for microvascular and macrovascular disease risk reduction in patients with recent-onset disease, no known cardiovascular diseases, and a longer life expectancy. In patients with known cardiovascular disease, a longer duration of diabetes (15 or more years), and a shorter life expectancy, however, tighter glycemic control is not as beneficial, particularly with regard to cardiovascular disease risk. Episodes of severe hypoglycemia may be particularly harmful in older individuals with poorer glycemic control and existing cardiovascular disease.
Agency for Healthcare Research and Quality. Comparative Effectiveness, Safety, and Indications of Insulin Analogues in Premixed Formulations for Adults With Type 2 Diabetes. AHRQ: Agency for Healthcare Research and Quality. Available at http://www.effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?productid=108&pageaction=displayproduct.. Accessed: March 7, 2012.
Learning about the disease and actively participating in the treatment is important, since complications are far less common and less severe in people who have well-managed blood sugar levels.[79][80] The goal of treatment is an HbA1C level of 6.5%, but should not be lower than that, and may be set higher.[81] Attention is also paid to other health problems that may accelerate the negative effects of diabetes. These include smoking, elevated cholesterol levels, obesity, high blood pressure, and lack of regular exercise.[81] Specialized footwear is widely used to reduce the risk of ulceration, or re-ulceration, in at-risk diabetic feet. Evidence for the efficacy of this remains equivocal, however.[82]
^ Zheng SL, Roddick AJ, Aghar-Jaffar R, Shun-Shin MJ, Francis D, Oliver N, Meeran K (April 2018). "Association Between Use of Sodium-Glucose Cotransporter 2 Inhibitors, Glucagon-like Peptide 1 Agonists, and Dipeptidyl Peptidase 4 Inhibitors With All-Cause Mortality in Patients With Type 2 Diabetes: A Systematic Review and Meta-analysis". JAMA. 319 (15): 1580–1591. doi:10.1001/jama.2018.3024. PMC 5933330. PMID 29677303.

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
There are a number of medications and other health problems that can predispose to diabetes.[41] Some of the medications include: glucocorticoids, thiazides, beta blockers, atypical antipsychotics,[42] and statins.[43] Those who have previously had gestational diabetes are at a higher risk of developing type 2 diabetes.[23] Other health problems that are associated include: acromegaly, Cushing's syndrome, hyperthyroidism, pheochromocytoma, and certain cancers such as glucagonomas.[41] Testosterone deficiency is also associated with type 2 diabetes.[44][45]
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.[114] 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.[114] 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.[114] This was followed by the development of the long acting NPH insulin in the 1940s.[114]
Diabetes mellitus is a chronic disease that requires long-term medical attention to limit the development of its devastating complications and to manage them when they do occur. It is a disproportionately expensive disease; in the United States in 2012, the direct and indirect costs of diagnosed diabetes were estimated to be $245 billion; people with diagnosed diabetes had average medical expenditures 2.3 times those of people without diabetes. [10, 11]
According to the National Institutes of Health, the reported rate of gestational diabetes is between 2% to 10% of pregnancies. Gestational diabetes usually resolves itself after pregnancy. Having gestational diabetes does, however, put mothers at risk for developing type 2 diabetes later in life. Up to 10% of women with gestational diabetes develop type 2 diabetes. It can occur anywhere from a few weeks after delivery to months or years later.

Amino acid metabolism may play a key role early in the development of type 2 diabetes. Wang et al reported that the risk of future diabetes was at least 4-fold higher in normoglycemic individuals with high fasting plasma concentrations of 3 amino acids (isoleucine, phenylalanine, and tyrosine). Concentrations of these amino acids were elevated up to 12 years prior to the onset of diabetes. [25] In this study, amino acids, amines, and other polar metabolites were profiled using liquid chromatography tandem mass spectrometry.
Prevention and treatment involve maintaining a healthy diet, regular physical exercise, a normal body weight, and avoiding use of tobacco.[2] Control of blood pressure and maintaining proper foot care are important for people with the disease.[2] Type 1 diabetes must be managed with insulin injections.[2] Type 2 diabetes may be treated with medications with or without insulin.[13] Insulin and some oral medications can cause low blood sugar.[14] Weight loss surgery in those with obesity is sometimes an effective measure in those with type 2 diabetes.[15] Gestational diabetes usually resolves after the birth of the baby.[16]
Erectile dysfunction is the difficulty achieving or maintaining an erection. If you have diabetes, you are 2 – 3 times more likely to have erectile dysfunction compared to men who are well; or experience the problem 10 – 15 years earlier. There is also research that suggests that erectile dysfunction may be an early marker of diabetes, particularly in younger men.
Low blood sugar, or hypoglycemia, is a syndrome in which a person's blood sugar is dangerously low. People with type 1 and type 2 diabetes are at risk for this condition. There are other diseases that can cause a person's blood sugar levels to go too low, for example, pancreatitis, Cushing's syndrome, and pancreatic cancer. Symptoms and signs that your blood sugar levels are too low include:

Diabetes is a metabolic disorder that occurs when your blood sugar (glucose), is too high (hyperglycemia). Glucose is what the body uses for energy, and the pancreas produces a hormone called insulin that helps convert the glucose from the food you eat into energy. When the body either does not produce enough insulin, does not produce any at all, or your body becomes resistant to the insulin, the glucose does not reach your cells to be used for energy. This results in the health condition termed diabetes.
Treatment for diabetes requires keeping close watch over your blood sugar levels (and keeping them at a goal set by your doctor) with a combination of medications, exercise, and diet. By paying close attention to what and when you eat, you can minimize or avoid the "seesaw effect" of rapidly changing blood sugar levels, which can require quick changes in medication dosages, especially insulin.
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.[10] A fasting or random blood sugar is preferred over the glucose tolerance test, as they are more convenient for people.[10] 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.[52] It is estimated that 20% of people with diabetes in the United States do not realize that they have the disease.[10]
The body obtains glucose from three main sources: the intestinal absorption of food; the breakdown of glycogen (glycogenolysis), the storage form of glucose found in the liver; and gluconeogenesis, the generation of glucose from non-carbohydrate substrates in the body.[62] Insulin plays a critical role in balancing glucose levels in the body. Insulin can inhibit the breakdown of glycogen or the process of gluconeogenesis, it can stimulate the transport of glucose into fat and muscle cells, and it can stimulate the storage of glucose in the form of glycogen.[62]
There is no known preventive measure for type 1 diabetes.[2] Type 2 diabetes—which accounts for 85–90% of all cases worldwide—can often be prevented or delayed by maintaining a normal body weight, engaging in physical activity, and eating a healthy diet.[2] Higher levels of physical activity (more than 90 minutes per day) reduce the risk of diabetes by 28%.[74] Dietary changes known to be effective in helping to prevent diabetes include maintaining a diet rich in whole grains and fiber, and choosing good fats, such as the polyunsaturated fats found in nuts, vegetable oils, and fish.[75] Limiting sugary beverages and eating less red meat and other sources of saturated fat can also help prevent diabetes.[75] Tobacco smoking is also associated with an increased risk of diabetes and its complications, so smoking cessation can be an important preventive measure as well.[76]

Genome-wide association studies of single-nucleotide polymorphisms (SNPs) have identified a number of genetic variants that are associated with beta-cell function and insulin resistance. Some of these SNPs appear to increase the risk for type 2 diabetes. Over 40 independent loci demonstrating an association with an increased risk for type 2 diabetes have been shown. [16] A subset of the most potent are shared below [17] :

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Patients using less frequent insulin injections or noninsulin therapies – Use SMBG results to adjust to food intake, activity, or medications to reach specific treatment goals; clinicians must not only educate these individuals on how to interpret their SMBG data, but they should also reevaluate the ongoing need for and frequency of SMBG at each routine visit.
Prevention and treatment involve maintaining a healthy diet, regular physical exercise, a normal body weight, and avoiding use of tobacco.[2] Control of blood pressure and maintaining proper foot care are important for people with the disease.[2] Type 1 diabetes must be managed with insulin injections.[2] Type 2 diabetes may be treated with medications with or without insulin.[13] Insulin and some oral medications can cause low blood sugar.[14] Weight loss surgery in those with obesity is sometimes an effective measure in those with type 2 diabetes.[15] Gestational diabetes usually resolves after the birth of the baby.[16]
A study by Zheng et al indicated that HbA1c levels in persons with diabetes are longitudinally associated with long-term cognitive decline, as found using a mean 4.9 cognitive assessments of diabetes patients over a mean 8.1-year follow-up period. The investigators saw a significant link between each 1 mmol/mol rise in HbA1c and an increased rate of decline in z scores for global cognition, memory, and executive function. Patients in the study had a mean age of 65.6 years. The report cited a need for research into whether optimal glucose control in people with diabetes can affect their cognitive decline rate. [77, 78]
Patients using less frequent insulin injections or noninsulin therapies – Use SMBG results to adjust to food intake, activity, or medications to reach specific treatment goals; clinicians must not only educate these individuals on how to interpret their SMBG data, but they should also reevaluate the ongoing need for and frequency of SMBG at each routine visit.
Inhalable insulin has been developed.[128] The original products were withdrawn due to side effects.[128] Afrezza, under development by the pharmaceuticals company MannKind Corporation, was approved by the United States Food and Drug Administration (FDA) for general sale in June 2014.[129] An advantage to inhaled insulin is that it may be more convenient and easy to use.[130]
Insulin is released into the blood by beta cells (β-cells), found in the islets of Langerhans in the pancreas, in response to rising levels of blood glucose, typically after eating. Insulin is used by about two-thirds of the body's cells to absorb glucose from the blood for use as fuel, for conversion to other needed molecules, or for storage. Lower glucose levels result in decreased insulin release from the beta cells and in the breakdown of glycogen to glucose. This process is mainly controlled by the hormone glucagon, which acts in the opposite manner to insulin.[63]

Patients with diabetes have a lifelong challenge to achieve and maintain blood glucose levels as close to the reference range as possible. With appropriate glycemic control, the risk of microvascular and neuropathic complications is decreased markedly. In addition, if hypertension and hyperlipidemia are treated aggressively, the risk of macrovascular complications decreases as well.
Regensteiner, J. G., Golden, S., Huebschmann, A. G., Barrett-Connor, E., Chang, A. Y., Chyun, D., … and Anton, B. (2015, December 7). Sex differences in the cardiovascular consequences of diabetes mellitus: A scientific statement from the American Heart Association. Circulation, 132, 2424-2447. Retrieved from https://www.ahajournals.org/doi/pdf/10.1161/cir.0000000000000343
^ Jump up to: a b c Vos T, Flaxman AD, Naghavi M, Lozano R, Michaud C, Ezzati M, et al. (December 2012). "Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010". Lancet. 380 (9859): 2163–96. doi:10.1016/S0140-6736(12)61729-2. PMC 6350784. PMID 23245607.
Dietary factors also influence the risk of developing type 2 diabetes. Consumption of sugar-sweetened drinks in excess is associated with an increased risk.[34][35] The type of fats in the diet are important, with saturated fats and trans fatty acids increasing the risk, and polyunsaturated and monounsaturated fat decreasing the risk.[27] Eating a lot of white rice appears to play a role in increasing risk.[36] A lack of exercise is believed to cause 7% of cases.[37] Persistent organic pollutants may play a role.[38]
The word mellitus (/məˈlaɪtəs/ or /ˈmɛlɪtəs/) comes from the classical Latin word mellītus, meaning "mellite"[117] (i.e. sweetened with honey;[117] honey-sweet[118]). The Latin word comes from mell-, which comes from mel, meaning "honey";[117][118] sweetness;[118] pleasant thing,[118] and the suffix -ītus,[117] whose meaning is the same as that of the English suffix "-ite".[119] It was Thomas Willis who in 1675 added "mellitus" to the word "diabetes" as a designation for the disease, when he noticed the urine of a diabetic had a sweet taste (glycosuria). This sweet taste had been noticed in urine by the ancient Greeks, Chinese, Egyptians, Indians, and Persians.
Insulin is released into the blood by beta cells (β-cells), found in the islets of Langerhans in the pancreas, in response to rising levels of blood glucose, typically after eating. Insulin is used by about two-thirds of the body's cells to absorb glucose from the blood for use as fuel, for conversion to other needed molecules, or for storage. Lower glucose levels result in decreased insulin release from the beta cells and in the breakdown of glycogen to glucose. This process is mainly controlled by the hormone glucagon, which acts in the opposite manner to insulin.[63]
In people with insulin resistance, the pancreas "sees" the blood glucose level rising. The pancreas responds by making extra insulin to maintain a normal blood sugar. Over time, the body's insulin resistance gets worse. In response the pancreas makes more and more insulin. Finally, the pancreas gets "exhausted". It cannot keep up with the demand for more and more insulin. It poops out. As a result, blood glucose levels start to rise.
^ 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. PMID 16034881. (Retracted, see doi:10.1002/14651858.cd002966.pub4. If this is an intentional citation to a retracted paper, please replace {{Retracted}} with {{Retracted|intentional=yes}}.)
Zinman B, DeVries JH, Bode B, Russell-Jones D, Leiter LA, Moses A, et al. Efficacy and safety of insulin degludec three times a week versus insulin glargine once a day in insulin-naive patients with type 2 diabetes: results of two phase 3, 26 week, randomised, open-label, treat-to-target, non-inferiority trials. Lancet Diabetes Endocrinol. 2013 Oct. 1 (2):123-31. [Medline].

Vascular diseases that prevent blood flow to the small blood vessels are common if you have diabetes. Nerve damage may also occur with longstanding diabetes. Since restricted blood flow and nerve damage can affect the feet in particular, you should make regular visits to a podiatrist. With diabetes, you may also have a reduced ability to heal blisters and cuts, even minor ones. A podiatrist can monitor your feet for any serious infections that could lead to gangrene and amputation. These visits do not take the place of daily foot checks you do yourself.
Hemoglobin A1c or HbA1c is a protein on the surface of red blood cells. The HbA1c test is used to monitor blood sugar levels in people with type 1 and type 2 diabetes over time. Normal HbA1c levels are 6% or less. HbA1c levels can be affected by insulin use, fasting, glucose intake (oral or IV), or a combination of these and other factors. High hemoglobin A1c levels in the blood increases the risk of microvascular complications, for example, diabetic neuropathy, eye, and kidney disease.

Severe autoimmune diabetes (SAID) - Essentially corresponding with type 1 diabetes and latent autoimmune diabetes in adults (LADA), this form is characterized by onset at a young age and patients with a relatively low body mass index (BMI), poor metabolic control, and impaired insulin production; in addition, this cluster is positive for glutamic acid decarboxylase antibodies (GADA)
^ Boussageon R, Bejan-Angoulvant T, Saadatian-Elahi M, Lafont S, Bergeonneau C, Kassaï B, Erpeldinger S, Wright JM, Gueyffier F, Cornu C (July 2011). "Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials". BMJ. 343: d4169. doi:10.1136/bmj.d4169. PMC 3144314. PMID 21791495.
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.[24][72] Lifestyle interventions are more effective than metformin.[24] A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal.[73] 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.[74]
These benefits are weighed against the risk of hypoglycemia and the short-term costs of providing high-quality preventive care. Studies have shown cost savings due to a reduction in acute diabetes-related complications within 1-3 years after starting effective preventive care. Some studies suggest that broad-based focus on treatment (eg, glycemia, nutrition, exercise, lipids, hypertension, smoking cessation) is much more likely to reduce the burden of excess microvascular and macrovascular events.
Metformin is generally recommended as a first line treatment for type 2 diabetes, as there is good evidence that it decreases mortality.[7] It works by decreasing the liver's production of glucose.[90] Several other groups of drugs, mostly given by mouth, may also decrease blood sugar in type II DM. These include agents that increase insulin release, agents that decrease absorption of sugar from the intestines, agents that make the body more sensitive to insulin, and agents that increase the excretion of glucose in the urine.[90] When insulin is used in type 2 diabetes, a long-acting formulation is usually added initially, while continuing oral medications.[7] Doses of insulin are then increased to effect.[7][91]
Skyler JS, Bergenstal R, Bonow RO, Buse J, Deedwania P, Gale EA, et al. Intensive glycemic control and the prevention of cardiovascular events: implications of the ACCORD, ADVANCE, and VA Diabetes Trials: a position statement of the American Diabetes Association and a Scientific Statement of the American College of Cardiology Foundation and the American Heart Association. J Am Coll Cardiol. 2009 Jan 20. 53(3):298-304. [Medline].
Type 2 diabetes occurs when the body does not produce enough insulin, or when the cells are unable to use insulin properly, which is called insulin resistance. Type 2 diabetes is commonly called “adult-onset diabetes” since it is diagnosed later in life, generally after the age of 45. It accounts for 90-95 percent of people with diabetes. In recent years, Type 2 diabetes has been diagnosed in younger people, including children, more frequently than in the past.
Here’s what you need to know about type 1 diabetes. 1.25 million Americans have it and 40,000 people will be diagnosed with it this year. Type 1 diabetes occurs at every age, in people of every race, and of every shape and size. There is no shame in having it, and you have a community of people ready to support you. Learning as much as you can about it and working closely with your diabetes care team can give you everything you need to thrive.
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