Diabetes mellitus type 2 (formerly noninsulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes) is a metabolic disorderthat is characterized by high blooglucose in the context of insulin resistance and relative insulin deficiency.[2] This is in contrast todiabetes mellitus type 1, in which there is an absolute insulin deficiency due to destruction of islet cells in t he pancreas.[3] The classic symptoms are excess thirst, frequent urination, and constant hunger. T ype 2 diabetes makes up about 90% of cases of diabetes with the other 10% due primarily to diabe tes mellitus type 1 and gestational diabetes. Obesity is thought to be the primary cause of type 2 di abetes in people who are genetically predisposed to the disease.Type 2 diabetes is initially managed by increasing exercise and dietary modification. If blood glu cose levels are not adequately lowered by these measures, medications suchas metformin or insulin may be needed. In those on insulin, there is typically the requirement to ro utinely check blood sugar levels.Rates of type 2 diabetes have increased markedly over the last 50 years in parallel with obesity: As of 2010 there are approximately 285 million people with the disease compared to around 30 milli on in 1985.[4][5]Long-term complications from high blood sugar can include heart disease,strokes, diabetic retinopathy where eyesight is affected, kidney failurewhich may require d ialysis, and poor circulation of limbs leading toamputations. The acute complication of ketoacidosi s, a feature of type 1 diabetes, is uncommon.[6] However, nonketotic hyperosmolar coma may occ ur.Signs and symptomsOverview of the most significant symptoms of diabetes.The classic symptoms of diabetes are polyuria (frequent urination), polydipsia (increased thirst), p olyphagia (increased hunger), and weight loss.[7] Other symptoms that are commonly present at d iagnosis include: a history of blurred vision,itchiness, peripheral neuropathy,recurrent vaginal infections, and fatigue. Many people, however, have no symptoms during the firs t few years and are diagnosed on routine testing. People with type 2 diabetes mellitus may rarely p resent with nonketotic hyperosmolar coma (a condition of very high blood sugar associated with a decreased level of consciousness and low blood pressure).10 References11 External linksSigns and symptomsOverview of the most significant symptoms of diabetes.The classic symptoms of diabetes are polyuria (frequentComplicationsMain article: Complications of diabetes mellitusType 2 diabetes is typically a chronic disease associated with a ten-year-shorter life expectancy.[4] This is partly due to a number of complications with which it is associated, includi ng: two to four times the risk of cardiovascular disease, includingischemic heart disease and stroke ; a 20-fold increase in lower limb amputations, and increased rates of hospitalizations.[4] In the de veloped world, and increasingly elsewhere, type 2 diabetes is the largest cause of nontraumatic blindnessand kidney failure.[8] It has also been associated with an increased risk of cognitive dysfunction and dementiathrough disease processes such as Alzheimer'disease and vascu lar dementia.[9] Other complications include:acanthosis nigricans, sexual dysfunction, and freque nt infections.[7]causeThe development of type 2 diabetes is caused by a combination of lifestyle and genetic factors.[8][ 10] While some are under personal control, such as diet and obesity, others, such as increasing age , female gender, and genetics, are not.[4] A lack of sleep has been linked to type 2 diabetes.[11] Th is is believed to act through its effect on metabolism.[11] The nutritional status of a mother during fetal development may also play a role, with one proposed mechanism being that of altered DNA methylationgeneticThere are a number of rare cases of diabetes that arise due to an abnormality in a single gen e (known asmonogenic forms of diabetes or "other specific types of diabetes").[3][4] These in clude maturity onset diabetes of the young (MODY), Donohue syndrome,and Rabson-Mendenhall syndrome, among others.[4] Maturity onset diabetes of the young c onstitute 1–5% of all cases of diabetes in young people.[18]Medical conditionsThere are a number of medications and other health problems that can predispose to diabetes.[19] Some of the medications include: glucocorticoids, thiazides, beta blockers, atyp ical antipsychotics,[20] andstatins.[21]Those who have previously had gestational diabetes ar e at a higher risk of developing type 2 diabetes.[7] Other health problems that are associated include: acromegaly, Cushing's syndrome, hyperthyroidism,pheochromocytoma, and certain cancers such as glucagonomas.[19] Testosterone deficiency is also associated with typ e 2 diabetes.[22][23]PathophysiologyType 2 diabetes is due to insufficient insulin production from beta cells in the setting of insuli n resistance.[3] Insulin resistance, which is the inability of cells to respond adequately to nor mal levels of insulin, occurs primarily within the muscles, liver, and fat tissue.[24] In the liver , insulin normally suppresses glucose release. However, in the setting of insulin resistance, th e liver inappropriately releases glucose into the blood.[4] 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.[3] Other potentially important mechanisms associ ated with type 2 diabetes and insulin resistance include: increased breakdown of lipids withi n fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased rete ntion of salt and water by the kidneys, and inappropriate regulation of metabolism by thecen tral nervous system.[4] However, not all people with insulin resistance develop diabetes, sinc e an impairment of insulin secretion by pancreatic beta cells is also required.[3] DiagnosisThe World Health Organizationdefinition of diabetes (both type 1 and type 2) is for a single raised glucose reading with symptoms, otherwise raised values on two occasions, of either:[2 7]fasting plasma glucose ≥ 7.0 mmol/l (126 mg/dl) orwith a glucose tolerance test, two hours after the oral dose a plasma glucose ≥ 11.1 mmol/ l(200 mg/dl)A random blood sugar of greater than 11.1 mmol/l (200 mg/dL) in association with typical sy mptoms[7] or aglycated hemoglobin (HbA1c) of greater than 6.5% is another method of diag nosing diabetes.[4] In 2009 an International Expert Committee that included representatives of the American Diabetes Association (ADA), the International Diabetes Federation (IDF), a nd the European Association for the Study of Diabetes (EASD) recommended that a threshold of ≥6.5% HbA1c should be used to diagnose diabetes. This recommendation was adopted by the American Diabetes Association in 2010.[28] Positive tests should be repeated unless the perso n presents with typical symptoms and blood sugars >11.1 mmol/l (>200 mg/dl).[29] Threshold for diagnosis of diabetes is based on the relationship between results of glucose tol erance tests, fasting glucose or HbA1c and complications such as retinal problems.[4] A fasti ng or random blood sugar is preferred over the glucose tolerance test, as they are more conv enient for people.[4] HbA1c has the advantages that fasting is not required and results are m ore stable but has the disadvantage that the test is more costly than measurement of blood gl ucose.[30] It is estimated that 20% of people with diabetes in the United States do not realize that they have the disease.[4]Diabetes mellitus type 2 is characterized by high blood glucose in the context of insulin resist ance and relative insulin deficiency.[2] This is in contrast to diabetes mellitus type 1 in which there is an absolute insulin deficiency due to destruction of islet cells inthe pancreas and gestational diabetes mellitus that is a new onset of high blood sugars in ass ociated with pregnancy.[3] Type 1 and type 2 diabetes can typically be distinguished based o n the presenting circumstances.[29] 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,[31] with C-peptide levels normal or high in type 2 diabetes, but low in type 1 diabet es.ScreeningNo major organization recommends universal screening for diabetes as there is no evidence t hat such a program would improve outcomes.[32] Screening is recommended by the United States Preventive Services Task Force in adults without symptoms whose blood pressure is gr eater than 135/80 mmHg.[33] For those whose blood pressure is less, the evidence is insuffici ent to recommend for or against screening.[33] The World Health Organizationrecommends only testing those groups at high risk.[32] High-risk groups in the United States include: those over 45 years old; those with a first degree relative with diabetes ; some ethnic groups, including Hispanics, African-Americans, and Native-Americans; a hist oryof gestational diabetes; polycystic ovary syndrome; excess weight; and conditions associated with metabolic syndrome.[7]PreventionMain article: Prevention of diabetes mellitus type 2Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular e xercise.[34][35]Intensive lifestyle measures may reduce the risk by over half.[8] The benefit o f exercise occurs regardless of the person's initial weight or subsequent weight loss.[36] Evid ence for the benefit of dietary changes alone, however, is limited,[37] with some evidence for a diet high in green leafy vegetables[38] and some for limiting the intake of sugary drinks.[13 ] In those with impaired glucose tolerance, diet and exercise either alone or in combination w ith metformin or acarbose may decrease the risk of developing diabetes.[8][39] Lifestyle inte rventions are more effective than metformin.[8]entionMain article: Prevention of diabetes mellitus type 2Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise .[34][35]Intensive lifestyle measures may reduce the risk by over half.[8] The benefit of exercise o ccurs regardless of the person's initial weight or subsequent weight loss.[36] Evidence for the bene fit of dietary changes alone, however, is limited,[37] with some evidence for a diet high in green le afy vegetables[38] and some for limiting the intake of sugary drinks.[13] In those with impaired gl ucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes.[8][39] Lifestyle interventions are more effective than met formin.[8]ManagementFurther information: Diabetes managementManagement of type 2 diabetes focuses on lifestyle interventions, lowering other cardiovascularrisk factors, and maintaining blood glucose levels in the normalrange.[8] Self-monitoring of blood glucose for people with newly diagnosed type 2 diabetes was r ecommended by the British National Health Service in 2008,[40] however the benefit of self moni toring in those not using multi-dose insulin is questionable.[8][41] Managing other cardiovascular risk factors, such as hypertension, high cholesterol, and microalbuminuria, improves a person's lif e expectancy.[8] Intensive blood pressure management (less than 130/80 mmHg) as opposed to sta ndard blood pressure management (less than140–160/85–100 mmHg) results in a slight decrease in stroke risk but no effect on overall risk of death.[42] Intensive blood sugar lowering (HbA1c<6%) as opposed to standard blood sugar lowering (HbA1c of 7–7.9%) does not appear to change mortality.[43][44] The goal of treatment is typically an HbA1c of less than 7% or a fasting glucose of less than 6.7 mmol/L (120 mg/dL) however these goals may b e changed after professional clinical consultation, taking into account particular risks of hypoglyce mia and life expectancy.[7] It is recommended that all people with type 2 diabetes get regular opht halmology examination.[3]LifestyleA proper diet and exercise are the foundations of diabetic care,[7] with a greater amount of e xercise yielding better results.[45] Aerobic exercise leads to a decrease in HbA1c and improv ed insulin sensitivity.[45]Resistance training is also useful and the combination of both types ofexercise may be most effective.[45] Adiabetic diet that promotes weight loss is important.[46] While the best diet type to achieve this is controversial[46] a low glycemic index diet has been found to improve blood sugar control.[47] Culturally appropriate education may help people with type 2 diabetes control their blood sugar levels, for up to six months at least.[48] If ch anges in lifestyle in those with mild diabetes has not resulted in improved blood sugars within six weeks, medications should then be considered.[7]MedicationsMetformin 500mg tabletsThere are several classes of anti-diabetic medications available. Metforminis generally recommen ded as a first line treatment as there is some evidence that it decreases mortality.[8] A second oral agent of another class may be used if metformin is not sufficient.[49] Other classes of medications include: sulfonylureas, nonsulfonylurea secretagogues, alpha glucosidase inhibitors, thiazolidined iones, glucagon-like peptide-1 analog, anddipeptidyl peptidase-4 inhibitors.[8][50] Metformin sho uld not be used in those with severe kidney or liver problems.[7] Injections of insulin may either be added to oral medication or used alone.[8]Most people do not initially need insulin.[3] When it is used, a long-acting formulation is typically added at night, with oral medications being continued.[7][8] Doses are then increased to effect (bl ood sugar levels being well controlled).[8] When nightly insulin is insufficient twice daily insulin may achieve better control.[7] The long acting insulins, glargine and detemir, do not appear much better than neutral protamine Hagedorn (NPH) insulin but have a significantly greater cost making them, as of 2010, not cost effective.[51] In those who are pregnant insulin is generally the treatme nt of choice.[7]SurgeryWeight loss surgery in those who are obese is an effective measure to treat diabetes.[52] Many are able to maintain normal blood sugar levels with little or no medications followingsurgery[53] and long term mortality is decreased.[54] There however is some short term mortality risk of less than 1% from the surgery.[55] The body mass index cutoffs for when surgery is approp riate are not yet clear.[54] It however is recommended that this option be considered in those who are unable to get both their weight and blood sugar under control.[56]Prevalence of diabetes worldwide in 2000 (per 1000 inhabitants). World average was 2.8%. Globally as of 2010 it was estimated that there were 285 million people with type 2 diabetes maki ng up about 90% of diabetes cases.[4] This is equivalent to about 6% of the world's adult populati on.[57] Diabetes is common both in the developed and the developing world.[4] It remains uncom mon, however, in the underdeveloped world.[3]Women seem to be at a greater risk as do certain ethnic groups,[4][58] such as South Asians, Pacif ic Islanders, Latinos, and Native Americans.[7] This may be due to enhanced sensitivity to a Weste rn lifestyle in certain ethnic groups.[59] Traditionally considered a disease of adults, type 2 diabete s is increasingly diagnosed in children in parallel withrising obesity rates.[4]Type 2 diabetes is now diagnosed as frequently as type 1 diabetes in teenage rs in the United States.[3]Rates of diabetes in 1985 were estimated at 30 million, increasing to 135 million in 1995 and 217 million in 2005.[5] This increase is believed to be primarily due to the global population aging, a d ecrease in exercise, and increasing rates of obesity.[5] 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 St ates 17.7 million, Indonesia 8.4 million, and Japan 6.8 million.[60] It is recognized as a global epi demic by the World Health Organization.[61]后面的这个比较简单大白话，-----What is DiabetesIf you have found your way to this page it is probably because you are searching for everything th ere is to know about diabetes. Knowledge is power. You have questions and you need answers to h ave power over this chronic disease.The diseases which are listed under Diabetes Mellitus are many with the most common being Typ e-1 diabetes and Type-2 diabetes. These are diseases of the metabolic system and involve the body 's ability in metabolizing sugar using the hormone insulin. Insulin helps the cells use the simple su gar glucose which is needed for repair, growth and energy.In Type-1 diabetes, the body produces little or no insulin so those with this type of diabetes need t o be on insulin therapy for their entire lives. Before 1924 Type-1 diabetes usually ended with dead after a couple of years but with the advent of insulin those who have this disease are now able to manage this chronic condition. Type-1 diabetes is also known as juvenile diabetes because those w ho have this type of diabetes are usually diagnosed with it between the ages of 9 and 15 years of a ge.With Type-2 diabetes, the body produces plenty of insulin but cells are unable to use it. This type of diabetes is the most common form of diabetes and although it used to normally develop in olde r adults, Type 2 diabetes is now developing at all ages. Major risk factors for Type-2 diabetes are u nhealthy diets, little or no exercise and being overweight or obese. There is currently a world wide epidemic of Type-2 diabetes which researchers believe is being driven in many areas because of s edentary life styles revolving around computers, video games, television and fast foods. Fast food restaurants are now in every corner of ourworld.Diabetes in the USCurrently in the United States 7.8% of the population or around 23.6 million people have diabetes with 5.7 million being undiagnosed. Most of those diagnosed have Type-2 diabetes and are usually 45 years of age or older. But this snapshot is changing as more children and adolescents are increa singly being diagnosed with this type of diabetes.Studies show that the most common complication of Type-2 diabetes is cardiovascular and it is als o the most costly complication at a cost of approximately $7 billion of the $44 billion annual direct medical costs for diabetes. This figure is from 1997 and many estimate that these figures could h ave doubled by now.Diabetes in IndiaAs of 2000 it was estimated that 171 million people globally suffered from diabetes or 2.8% of the population. Type-2 diabetes is the most common type worldwide.Figures for the year 2007 show that the 5 countries with the largest amount of people diagnosed w ith diabetes were India (40.9 million), China (38.9 million), US (19.2 million), Russia (9.6 million ), and Germany (7.4 million).Currently, India is the diabetes capital of the world. It is estimated that over 40 million of those wit h diabetes are currently in India and that by 2025 that number will grow to 70 million. In other wo rds, 1 in every 5 diabetics in the world will live in India. Diabetes is the number one cause of kidn ey failure, is responsible for 5% of blindness in adults and 1 million limb amputations. Because of the chronic nature of diabetes, the relentlessness of its complications and the means re quired to control both diabetes and its complications; this disease is very costly, not only for affect ed individuals and families but also for the healthcare systems. Studies done in India estimate that for a low income family with an adult having diabetes, as much as 25% of the family's income ma y need to be devoted to diabetes care.Stress also seems to be a greater risk factor in India for diabetes. It is important to de-stress accord ing to each one's disposition - for example spending quality time with friends and family, Yoga, br eathing exercises, walking, meditation, aerobics and other fitness regimen can ward off diabetes.Preliminary findings of a recent study in India among school children in the higher socio-economi c group in Chennai showed child obesity is growing higher and girlswere found to be disproportionately "heavier" than boys.Stopping the EpidemicIt is really fairly simple - medical professionals believe that turning off the TV and computer and g oing outside to walk or exercise will go a long way to stopping this epidemic. Other suggestions in clude cutting calories in diets, snacking on whole grain and high-fiber foods, avoiding smoking an d alcohol, exercising regularly and getting stress levels under control are pro-active ways to keep t his diabetic epidemic from continuing to grow.。
