Being too heavy gets the bulk of the blame for triggering type 2 diabetes. According to the National Institutes of Health, about 85 percent of people with type 2 diabetes are overweight or obese. But consider that the remaining 15 percent are not. Consider, too, that roughly two-thirds of overweight people and a third of those who are obese will never develop diabetes. In other words, normal-weight and thin people also develop type 2, while heavy people won't necessarily. Clearly, there is more to the connection between lifestyle and type 2 diabetes than just body size.
Jump up ^ Feinman, RD; Pogozelski, WK; Astrup, A; Bernstein, RK; Fine, EJ; Westman, EC; Accurso, A; Frassetto, L; Gower, BA; McFarlane, SI; Nielsen, JV; Krarup, T; Saslow, L; Roth, KS; Vernon, MC; Volek, JS; Wilshire, GB; Dahlqvist, A; Sundberg, R; Childers, A; Morrison, K; Manninen, AH; Dashti, HM; Wood, RJ; Wortman, J; Worm, N (January 2015). "Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base". Nutrition. Burbank, Los Angeles County, Calif. 31 (1): 1–13. doi:10.1016/j.nut.2014.06.011. PMID 25287761.
Type 2 diabetes usually begins with insulin resistance, a condition in which muscle, liver, and fat cells do not use insulin well. As a result, your body needs more insulin to help glucose enter cells. At first, the pancreas makes more insulin to keep up with the added demand. Over time, the pancreas can’t make enough insulin, and blood glucose levels rise.
The classic oral glucose tolerance test measures blood glucose levels five times over a period of three hours. Some physicians simply get a baseline blood sample followed by a sample two hours after drinking the glucose solution. In a person without diabetes, the glucose levels rise and then fall quickly. In someone with diabetes, glucose levels rise higher than normal and fail to come back down as fast.
Patients with type 2 diabetes can still make insulin, but not enough to control their glucose levels. Type 2 diabetes is therefore initially treated with a combination of lifestyle changes (diet and exercise) which reduce the need for insulin and therefore lower glucose levels. If this is insufficient to achieve good glucose control, a range of tablets are available. These include metformin and pioglitazone, which, like diet and exercise, reduce insulin requirements; sulphonylureas (e.g. gliclazide), which stimulate insulin secretion; DPP4 inhibitors (e.g sitagliptin) and GLP-1 agonists (e.g. liraglutide), which stimulate insulin production and reduce appetite; and SGLT2 inhibitors (e.g. dapagliflozin), which lower blood sugar levels by causing sugar to pass out of the body in the urine. In many patients, particularly after several years of treatment, insulin production is so low or so insufficient compared with the patient's needs that patients with type 2 diabetes have to be treated with insulin injections, either alone or in combination with tablets.
Diabetes mellitus results mainly from a deficiency or diminished effectiveness of insulin that is normally produced by the beta cells of the pancreas. It is characterised by high blood sugar, altered sugar and glucose metabolism and this affects blood vessels and causes several organ damage. Causes of diabetes can be classified according to the types of diabetes.
People usually develop type 2 diabetes after the age of 40 years, although people of South Asian origin are at an increased risk of the condition and may develop diabetes from the age of 25 onwards. The condition is also becoming increasingly common among children and adolescents across all populations. Type 2 diabetes often develops as a result of overweight, obesity and lack of physical activity and diabetes prevalence is on the rise worldwide as these problems become more widespread.
Diabetes mellitus (DM) is best defined as a syndrome characterized by inappropriate fasting or postprandial hyperglycemia, caused by absolute or relative insulin deficiency and its metabolic consequences, which include disturbed metabolism of protein and fat. This syndrome results from a combination of deficiency of insulin secretion and its action. Diabetes mellitus occurs when the normal constant of the product of insulin secretion times insulin sensitivity, a parabolic function termed the “disposition index” (Figure 19-1), is inadequate to prevent hyperglycemia and its clinical consequences of polyuria, polydipsia, and weight loss. At high degrees of insulin sensitivity, small declines in the ability to secrete insulin cause only mild, clinically imperceptible defects in glucose metabolism. However, irrespective of insulin sensitivity, a minimum amount of insulin is necessary for normal metabolism. Thus, near absolute deficiency of insulin must result in severe metabolic disturbance as occurs in type 1 diabetes mellitus (T1DM). By contrast, with decreasing sensitivity to its action, higher amounts of insulin secretion are required for a normal disposition index. At a critical point in the disposition index curve (see Figure 19-1), a further small decrement in insulin sensitivity requires a large increase in insulin secretion; those who can mount these higher rates of insulin secretion retain normal glucose metabolism, whereas those who cannot increase their insulin secretion because of genetic or acquired defects now manifest clinical diabetes as occurs in type 2 diabetes (T2DM).
The more common form of diabetes, Type II, occurs in approximately 3-5% of Americans under 50 years of age, and increases to 10-15% in those over 50. More than 90% of the diabetics in the United States are Type II diabetics. Sometimes called age-onset or adult-onset diabetes, this form of diabetes occurs most often in people who are overweight and who do not exercise. It is also more common in people of Native American, Hispanic, and African-American descent. People who have migrated to Western cultures from East India, Japan, and Australian Aboriginal cultures also are more likely to develop Type II diabetes than those who remain in their original countries.
Some older people cannot control what they eat because someone else is cooking for them—at home or in a nursing home or other institution. When people with diabetes do not do their own cooking, the people who shop and prepare meals for them must also understand the diet that is needed. Older people and their caregivers usually benefit from meeting with a dietitian to develop a healthy, feasible eating plan.
There are a range of different symptoms in people with diabetes. They may feel thirsty, pass a large amount of urine, wake up overnight to pass urine, lose weight and have blurred vision. Patients are vulnerable to infections such as thrush and may present with this. Particularly in type 2 diabetes, patients may not be aware of their diabetes for several years and a diagnosis may only be made when they seek treatment for diabetes-related complications such as foot, eye or kidney problems. Some patients may become severely ill and be taken into hospital with an infection and/or very high blood sugar levels.
The major eye complication of diabetes is called diabetic retinopathy. Diabetic retinopathy occurs in patients who have had diabetes for at least five years. Diseased small blood vessels in the back of the eye cause the leakage of protein and blood in the retina. Disease in these blood vessels also causes the formation of small aneurysms (microaneurysms), and new but brittle blood vessels (neovascularization). Spontaneous bleeding from the new and brittle blood vessels can lead to retinal scarring and retinal detachment, thus impairing vision.
Diabetes also can cause heart disease and stroke, as well as other long-term complications, including eye problems, kidney disease, nerve damage, and gum disease. While these problems don't usually show up in kids or teens who've had type 2 diabetes for only a few years, they can affect them in adulthood, particularly if their diabetes isn't well controlled.
A healthy lifestyle can prevent almost all cases of type 2 diabetes. A large research study called the Diabetes Prevention Program, found that patients who made intensive changes including diet and exercise, reduced their risk of developing diabetes by 58%. Patients who were over 60 years old seemed to experience extra benefit; they reduced their risk by 71%. In comparison, patients who were given the drug metformin for prevention only reduced their risk by 31%.
Apart from these medications, treating diabetes effectively means taking a well-rounded approach: You’ll need to eat well, exercise, and manage stress, because all these factors can affect your blood sugar levels. Staying healthy with diabetes also requires caring for yourself — like protecting your feet, practicing oral hygiene, and tending to your mental health.
Per the WHO, people with fasting glucose levels from 6.1 to 6.9 mmol/l (110 to 125 mg/dl) are considered to have impaired fasting glucose. people with plasma glucose at or above 7.8 mmol/l (140 mg/dl), but not over 11.1 mmol/l (200 mg/dl), two hours after a 75 gram oral glucose load are considered to have impaired glucose tolerance. Of these two prediabetic states, the latter in particular is a major risk factor for progression to full-blown diabetes mellitus, as well as cardiovascular disease. The American Diabetes Association (ADA) since 2003 uses a slightly different range for impaired fasting glucose of 5.6 to 6.9 mmol/l (100 to 125 mg/dl).
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
A 2018 study suggested that three types should be abandoned as too simplistic. It classified diabetes into five subgroups, with what is typically described as type 1 and autoimmune late-onset diabetes categorized as one group, whereas type 2 encompasses four categories. This is hoped to improve diabetes treatment by tailoring it more specifically to the subgroups.
In the sunshine, molecules in the skin are converted to vitamin D. But people stay indoors more these days, which could lead to vitamin D deficiency. Research shows that if mice are deprived of vitamin D, they are more likely to become diabetic. In people, observational studies have also found a correlation between D deficiency and type 1. "If you don't have enough D, then [your immune system] doesn't function like it should," says Chantal Mathieu, MD, PhD, a professor of experimental medicine and endocrinology at Katholieke Universiteit Leuven in Belgium. "Vitamin D is not the cause of type 1 diabetes. [But] if you already have a risk, you don't want to have vitamin D deficiency on board because that's going to be one of the little pushes that pushes you in the wrong direction."
Metformin is generally recommended as a first line treatment for type 2 diabetes, as there is good evidence that it decreases mortality. It works by decreasing the liver's production of glucose. 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, and agents that make the body more sensitive to insulin. When insulin is used in type 2 diabetes, a long-acting formulation is usually added initially, while continuing oral medications. Doses of insulin are then increased to effect.
Blurred vision can result from elevated blood sugar. Similarly, fluid that is pulled from the cells into the bloodstream to dilute the sugar can also be pulled from the lenses of your eyes. When the lens of the eye becomes dry, the eye is unable to focus, resulting in blurry vision. It's important that all people diagnosed with type 2 diabetes have a dilated eye exam shortly after diagnosis. Damage to the eye can even occur before a diagnosis of diabetes exists.
Home blood sugar (glucose) testing is an important part of controlling blood sugar. One important goal of diabetes treatment is to keep the blood glucose levels near the normal range of 70 to 120 mg/dl before meals and under 140 mg/dl at two hours after eating. Blood glucose levels are usually tested before and after meals, and at bedtime. The blood sugar level is typically determined by pricking a fingertip with a lancing device and applying the blood to a glucose meter, which reads the value. There are many meters on the market, for example, Accu-Check Advantage, One Touch Ultra, Sure Step and Freestyle. Each meter has its own advantages and disadvantages (some use less blood, some have a larger digital readout, some take a shorter time to give you results, etc.). The test results are then used to help patients make adjustments in medications, diets, and physical activities.
Recently, battery-operated insulin pumps have been developed that can be programmed to mimic normal insulin secretion more closely. A person wearing an insulin pump still must monitor blood sugar several times a day and adjust the dosage, and not all diabetic patients are motivated or suited to such vigilance. It is hoped that in the future an implantable or external pump system may be perfected, containing a glucose sensor. In response to data from the sensor the pump will automatically deliver insulin according to changing levels of blood glucose.
Healthy lifestyle choices can help you prevent type 2 diabetes. Even if you have diabetes in your family, diet and exercise can help you prevent the disease. If you've already received a diagnosis of diabetes, you can use healthy lifestyle choices to help prevent complications. And if you have prediabetes, lifestyle changes can slow or halt the progression from prediabetes to diabetes.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Longer-term, the goals of treatment are to prolong life, reduce symptoms, and prevent diabetes-related complications such as blindness, kidney failure, and amputation of limbs. These goals are accomplished through education, insulin use, meal planning and weight control, exercise, foot care, and careful self-testing of blood glucose levels. Self-testing of blood glucose is accomplished through regular use of a blood glucose monitor (pictured, right). This machine can quickly and easily measure the level of blood glucose based by analysing the level from a small drop of blood that is usually obtained from the tip of a finger. You will also require regular tests for glycated haemoglobin (HbA1c). This measures your overall control over several months.
For example, the environmental trigger may be a virus or chemical toxin that upsets the normal function of the immune system. This may lead to the body’s immune system attacking itself. The normal beta cells in the pancreas may be attacked and destroyed. When approximately 90% of the beta cells are destroyed, symptoms of diabetes mellitus begin to appear. The exact cause and sequence is not fully understood but investigation and research into the disease continues.
Inhalable insulin has been developed. The original products were withdrawn due to side effects. 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. An advantage to inhaled insulin is that it may be more convenient and easy to use.
At present, the American Diabetes Association does not recommend general screening of the population for type 1 diabetes, though screening of high risk individuals, such as those with a first degree relative (sibling or parent) with type 1 diabetes should be encouraged. Type 1 diabetes tends to occur in young, lean individuals, usually before 30 years of age; however, older patients do present with this form of diabetes on occasion. This subgroup is referred to as latent autoimmune diabetes in adults (LADA). LADA is a slow, progressive form of type 1 diabetes. Of all the people with diabetes, only approximately 10% have type 1 diabetes and the remaining 90% have type 2 diabetes.