pathological degeneration of mitochondria in these cells may compromise their normal functions and contribute to abnormalities in the control of blood glucose by the hypothalamus. diagnosis who diabetes diagnostic criteria condition 2-hour glucose fasting glucose hba1c unit mmol/lmg/dl mmol/lmg/dl mmol/moldcct % normal< 7.8< 140< 6.1< 110< 42< 6.0 impaired fasting glycaemia< 7.8< 1406.1–7.0110–12542–466.0–6.4 impaired glucose tolerance≥ 7.8≥ 140< 7.0< 12642–466.0–6.4 diabetes mellitus≥ 11.1≥ 200≥ 7.0≥ 126≥ 48≥ 6.5 the world health organization definition 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: fasting plasma glucose ≥ 7.0 mmol/l (126 mg/dl) or with 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 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). ada diabetes diagnostic criteria in 2015 diabetes mellitus prediabetes hba1c ≥6.5% 5.7-6.4% fasting glucose ≥126 mg/dl 100-125 mg/dl 2h glucose ≥200 mg/dl 140-199 mg/dl random glucose with classic symptoms ≥200 mg/dl not available 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. screening universal screening for diabetes in people without risk factors or symptoms is not recommended. screening is recommended by the world health organization, the united states preventive services task force (uspstf), and the american diabetes association for high-risk adults. risk factors considered by the uspstf include adults over 35 years old who are overweight or have obesity and 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. the american diabetes society recommends screening for adults with a body mass index (bmi) over 25. for people of asian descent, screening is recommended if they have a bmi over 23. other high risk groups include people with a first degree relative with diabetes; some ethnic groups, including hispanics, african-americans, and native-americans; a history of gestational diabetes; polycystic ovary syndrome; excess weight; and conditions associated with metabolic syndrome. there is no evidence that screening changes the risk of death and any benefit of screening on adverse effects, incidence of type 2 diabetes, hba1c or socioeconomic effects are not clear. in the uk, nice guidelines suggest taking action to prevent diabetes for people with a body mass index (bmi) of 30 or more. for people of black african, african-caribbean, south asian and chinese descent the recommendation to start prevention starts at the bmi of 27,5. a study based on a large sample of people in england suggest even lower bmis for certain ethnic groups for the start of prevention, for example 24 in south asian and 21 in bangladeshi populations. prevention main article: prevention of type 2 diabetes onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise. 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, a 2019 systematic review found moderate-quality evidence that metformin, when compared to diet and exercise or a placebo intervention, appeared to delay or reduce the risk of developing type 2 diabetes. this same review found moderate-quality evidence that when compared to intensive diet and exercise, metformin did not reduce risk of developing type 2 diabetes, as well as very low-quality evidence that combining metformin with intensive diet and exercise does not appear to have any effect on risk of developing type 2 diabetes when compared to intensive diet and exercise alone. this systematic review only found one suitable trial comparing metformin with sulphonylurea in reducing risk of type 2 diabetes but it did not report any patient-relevant outcomes. a cochrane systematic review assessed the effect of alpha-glucosidase inhibitors in people with impaired glucose tolerance, impaired fasting blood glucose, elevated glycated hemoglobin a1c (hba1c).it was found that acarbose appeared to reduce incidence of diabetes mellitus type 2 when compared to placebo, however there was no conclusive evidence that acarbose compare to diet and exercise, metformin, placebo, no intervention improved all-cause mortality, reduced or increased risk of cardiovascular mortality, serious or non-serious adverse events, non-fatal stroke, congestive heart failure, or non-fatal myocardial infarction.the same review found that there was no conclusive evidence that voglibose compared to diet and exercise or placebo reduced incidence of diabetes mellitus type 2, or any of the other measured outcomes. 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 further information: diabetes management 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 moderate evidence suggesting that treating gum disease by scaling and root planing results in an improvement in blood sugar levels for people with diabetes. exercise a proper diet and regular exercise are foundations of diabetic care, with one review indicating that a greater amount of exercise improved outcomes. regular exercise may improve blood sugar control, decrease body fat content, and decrease blood lipid levels. diet a diabetic diet which includes calorie restriction to promote weight loss is generally recommended. other recommendations include emphasizing intake of fruits, vegetables, reduced saturated fat and low-fat dairy products, and with a macronutrient intake tailored to the individual, to distribute calories and carbohydrates throughout the day. several diets may be effective such as the dietary approaches to stop hypertension (dash), mediterranean diet, low-fat diet, or monitored carbohydrate diets such as a low carbohydrate diet. viscous fiber supplements may be useful in those with diabetes. 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. a 2021 review showed that consumption of tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose in diabetic people. culturally appropriate education may help people with type 2 diabetes control their blood sugar levels for up to 24 months. there is not enough evidence to determine if lifestyle interventions affect mortality in those who already have type 2 diabetes. as of 2015, there is insufficient data to recommend nonnutritive sweeteners, which may help reduce caloric intake. an elevated intake of microbiota-accessible carbohydrates can help reducing the effects of t2d. a 2022 umbrella review concluded that, red and white meat consumption is associated with an increased risk contrary to dairy products which have a diminished risk. stress management although psychological stress is recognized as a risk factor for type 2 diabetes, the effect of stress management interventions on disease progression are not established. a cochrane review is under way to assess the effects of mindfulness‐based interventions for adults with type 2 diabetes. medications metformin 500 mg tablets blood sugar control