Unlike Type 1 diabetes, there is little tendency toward ketoacidosis in Type 2 diabetes, though it is not unknown. One effect that can occur is nonketonic hyperglycemia which also is quite dangerous, though it must be treated very differently. Complex and multifactorial metabolic changes very often lead to damage and function impairment of many organs, most importantly the cardiovascular system in both types. This leads to substantially increased morbidity and mortality in both Type 1 and Type 2 patients, but the two have quite different origins and treatments despite the similarity in complications.
Other important contributing factors:
This is a more complex problem than Type 1, but is sometimes easier to treat, especially in the early years when insulin is often still being produced internally. Type 2 may go unnoticed for years before diagnosis, since symptoms are typically milder (eg, no ketoacidosis, coma, etc) and can be sporadic. However, severe complications can result from improperly managed Type 2 diabetes, including renal failure, blindness, slow healing wounds (including surgical incisions), and arterial disease, including coronary artery disease. The onset of Type 2 has been most common in middle age and later life, although it is being more frequently seen in adolescents and young adults due to an increasing rate of obesity in these groups. A type of Type 2 diabetes called MODY is occasionally also seen in adolescents.
Diabetes mellitus type 2 is presently of unknown etiology (i.e., origin). Diabetes mellitus with a known etiology, such as secondary to other diseases, known gene defects, trauma or surgery, or the effects of drugs, is more appropriately called secondary diabetes mellitus. Examples include diabetes mellitus caused by hemochromatosis, pancreatic insufficiencies, or certain types of medications (e.g. long-term steroid use).
According to CDC about 23.6 million people in the United States, or 8% of the population, who have diabetes. The total prevalence of diabetes increased 13.5% from 2005-2007. Only 24% of diabetes is undiagnosed, down from 30% in 2005 and from 50% ten years ago.
About 90–95% of all North American cases of diabetes are type 2, and about 20% of the population over the age of 65 has diabetes mellitus Type 2. The fraction of Type 2 diabetics in other parts of the world varies substantially, almost certainly for environmental and lifestyle reasons, though these are not known in detail. Diabetes affects over 150 million people worldwide and this number is expected to double by 2025. There is also a strong inheritable genetic connection in Type 2 diabetes: having relatives (especially first degree) with Type 2 increases risks of developing Type 2 diabetes very substantially. In addition, there is also a mutation to the Islet Amyloid Polypeptide gene that results in an earlier onset, more severe, form of diabetes. About 55 percent of type 2 are obese —chronic obesity leads to increased insulin resistance that can develop into diabetes, most likely because adipose tissue (especially that in the abdomen around internal organs) is a (recently identified) source of several chemical signals to other tissues (hormones and cytokines). Other research shows that Type 2 diabetes causes obesity as an effect of the changes in metabolism and other deranged cell behavior attendant on insulin resistance.
Diabetes mellitus Type 2 is often associated with obesity, hypertension, elevated cholesterol (combined hyperlipidemia), and with the condition often termed Metabolic syndrome (it is also known as Syndrome X, Reavan's syndrome, or CHAOS). It is also associated with acromegaly, Cushing's syndrome and a number of other endocrinological disorders. Additional factors found to increase risk of type 2 diabetes include aging, high-fat diets and a less active lifestyle..
A common initial symptom of type 2 is a faint smell of fruit or vegetable odor on the breath. This is caused by ketosis induced by lack of response to insulin, leading to lack of glucose internal to cells. It commonly accompanies high blood glucose levels, which are also a result of decreased sensitivity to insulin.
Interest has arisen in preventing diabetes due to research on the benefits of treating patients before overt diabetes. Although the U.S. Preventive Services Task Force concluded that "the evidence is insufficient to recommend for or against routinely screening asymptomatic adults for type 2 diabetes, impaired glucose tolerance, or impaired fasting glucose," this was a grade I recommendation when published in 2003. However, the USPSTF does recommend screening for diabetics in adults with hypertension or hyperlipidemia (grade B recommendation).
In 2005, an evidence report by the Agency for Healthcare Research and Quality concluded that "there is evidence that combined diet and exercise, as well as drug therapy (metformin, acarbose), may be effective at preventing progression to DM in IGT subjects".
A random capillary blood glucose > 6.7 mmol/L (120 mg/dL) diagnoses current diabetes with:
Glycosylated hemoglobin values that are elevated (over 5%), but not in the diabetic range (not over 7.0%) are predictive of subsequent clinical diabetes in US female health professionals. In this study, 177 of 1061 patients with glycosylated hemoglobin value less than 6% became diabetic within 5 years compared to 282 of 26281 patients with a glycosylated hemoglobin value of 6.0% or more. This equates to a glycosylated hemoglobin value of 6.0% or more having:
The first goal can be achieved through close glycemic control (i.e., to near 'normal' blood glucose levels); the reduction in severity of diabetic side effects has been very well demonstrated in several large clinical trials and is established beyond controversy. The second goal is often addressed (in developed countries) by support and care from teams of diabetic health workers (usually physician, PA, nurse, dietitian or a certified diabetic educator). Endocrinologists, family practitioners, and general internists are the physician specialties most likely to treat people with diabetes. Knowledgeable patient participation is vital to clinical success, and so patient education is a crucial aspect of this effort.
Type 2 is initially treated by adjustments in diet and exercise, and by weight loss, most especially in obese patients. The amount of weight loss which improves the clinical picture is sometimes modest (2-5 kg or 4.4-11 lb); this is almost certainly due to currently poorly understood aspects of fat tissue activity, for instance chemical signaling (especially in visceral fat tissue in and around abdominal organs). In many cases, such initial efforts can substantially restore insulin sensitivity. In some cases strict diet can adequetly control the glycemic levels.
The targets are:
In older patients, clinical practice guidelines by the American Geriatrics Society) states "for frail older adults, persons with life expectancy of less than 5 years, and others in whom the risks of intensive glycemic control appear to outweigh the benefits, a less stringent target such as 8% is appropriate".
The National Institute for Health and Clinical Excellence (NICE), UK released updated diabetes recommendations on 30th May 2008. They indicate that self-monitoring of blood glucose levels for people with newly diagnosed type 2 diabetes should be part of a structured self-management education plan. However, a recent study found that a treatment strategy of intensively lowering blood sugar levels (below 6%) in patients with additional cardiovascular disease risk factors poses more harm than benefit, and so there appear to be limits to benefit of intensive blood glucose control in some patients.
Modifying the diet to limit and control glucose (or glucose equivalent, eg starch) intake, and in consequence, blood glucose levels, is known to assist type 2 patients, especially early in the course of the disease's progression. Additionally, weight loss is recommended and is often helpful in persons suffering from Type 2 diabetes for the reasons discussed above.
Several dietary modifications using dietary supplements are sometimes recommended to those with Type 2; there are studies suggesting that there is some beneficial effect for some of these. See the discussion below.
Diabetes self-management education is an integral component of medical care. Among adults with diagnosed diabetes, 12% take both insulin and oral medications,19% take insulin only, 53% take oral medications only, and 15% do not take either insulin or oral medications.
Traditionally, information regarding diabetes would be obtained from a family physician. However, with access to the internet so widely available now, people are able to educate themselves through websites. This information can be beneficial, but care must be taken to ensure the information is medically sound. Several of the external links below provide information about diabetes and its management, including self-management.
Theoretically, exercise does have benefits in that exercise would stimulate the release certain ligands that cause GLUT4 to be released from internal endosomes to the cell membrane. Insulin though, which no longer works effectively in those afflicted with Type II diabetes, causes GLUT1 to be placed into the membrane. Though they have different structures, they both perform the same function of increasing intake of glucose into the cell from the blood serum.
One of the most widely used drugs now used for Type 2 diabetes is the Biguanide metformin; it works primarily by reducing liver release of blood glucose from glycogen stores and secondarily by provoking some increase in cellular uptake of glucose in body tissues. Both historically, and currently, the most commonly used drugs are in the Sulfonylurea group, of which several members (including glibenclamide and gliclazide) are widely used; these increase glucose stimulated insulin secretion by the pancreas and so lower blood glucose even in the face of insulin resistance.
Newer drug classes include:
For patients who also have heart failure, metformin may be the best tolerated drug.
The variety of available agents can be confusing, and the clinical differences among Type 2 diabetics compounds the problem. At present, choice of drugs for Type 2 diabetics is rarely straightforward and in most instances has elements of repeated trial and adjustment.
A systematic review and meta-analysis of randomized controlled trials found that, compared to placebo, GLP-1 analogs such as exenatide lowered A1c values by 0.97% while DPP-4 inhibitors lowered A1c by 0.74%, comparable to other antidiabetic drugs. GLP-1 analogs resulted in weight loss and had more gastrointestinal side effects, while DPP-4 inhibitors were weight neutral and increased risk for infection and headache, but both classes appear to present an alternative to other antidiabetic drugs.
Typical total daily dosage of insulin is 0.6 U/kg. But, of course, best timing and indeed total amounts depend on diet (composition, amount, and timing) as well the degree of insulin resistance. More complicated estimations to guide initial dosage of insulin are:
The initial insulin regimen are often chosen based on the patient's blood glucose profile. Initially, adding nightly insulin to patients failing oral medications may be best. Nightly insulin combines better with metformin than with sulfonylureas. The initial dose of nightly insulin (measured in IU/d) should be equal to the fasting blood glucose level (measured in mmol/L). If the fasting glucose is reported in mg/dl, multiply by 0.05551 to convert to mmol/L.
When nightly insulin is insufficient, choices include:
Neither of these have shown permanent positive effects, nor a complete restoration to pre-diabetes conditions, only improvement. Their clinical importance in humans remains unclear.
Chromium (Chromium Picolinate, CrPic) is has been showed with increasing evidence to have significant positive effect to patients with type 2 diabetes.
Vinegar has been shown to reduce glucose spikes at mealtimes.
The goal blood pressure is 130/80 which is lower than in non-diabetic patients.
A study of 20-years of Greenville gastric bypass patients found that 80% of those with Type 2 diabetes before surgery no longer required insulin or oral agents to maintain normal glucose levels. Weight loss occurred rapidly in many people in the study who had had the surgery. The 20% who did not respond to bypass surgery were, typically, those who were older and had had diabetes for over 20 years.
In January 2008, The Journal of the American Medical Association (JAMA) published the first randomized controlled trial comparing the efficacy of laparoscopic adjustable gastric banding against conventional medical therapy in the obese patient with type 2 diabetes. Laparoscopic Adjustable Gastric Banding results in remission of Type 2 diabetes among affected patients diagnosed within the previous two years according to a randomized controlled trial. The relative risk reduction was 69.0%. For patients at similar risk to those in this study (87.0% had Type 2), this leads to an absolute risk reduction of 60%. 1.7 patients must be treated for one to benefit (number needed to treat = 1.7). Click here to adjust these results for patients at higher or lower risk of Type 2 diabetics.