The American Diabetes Association sponsored an international panel in 1995 to review the literature and recommend updates of the classification of diabetes mellitus. The definitions and descriptions that follow are drawn from the Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. The report was first approved in 1997 and modified in 1999. Although other terms are found in older literature and remain in use, their use in current clinical practice is inappropriate. Epidemiologic and research studies are facilitated by use of a common language.
As of 2016, 422 million people have diabetes worldwide, up from an estimated 382 million people in 2013 and from 108 million in 1980. Accounting for the shifting age structure of the global population, the prevalence of diabetes is 8.5% among adults, nearly double the rate of 4.7% in 1980. Type 2 makes up about 90% of the cases. Some data indicate rates are roughly equal in women and men, but male excess in diabetes has been found in many populations with higher type 2 incidence, possibly due to sex-related differences in insulin sensitivity, consequences of obesity and regional body fat deposition, and other contributing factors such as high blood pressure, tobacco smoking, and alcohol intake.
The prognosis of diabetes is related to the extent to which the condition is kept under control to prevent the development of the complications described in the preceding sections. Some of the more serious complications of diabetes such as kidney failure and cardiovascular disease, can be life-threatening. Acute complications such as diabetic ketoacidosis can also be life-threatening. As mentioned above, aggressive control of blood sugar levels can prevent or delay the onset of complications, and many people with diabetes lead long and full lives.
Although age of onset and length of the disease process are related to the frequency with which vascular, renal, and neurologic complications develop, there are some patients who remain relatively free of sequelae even into the later years of their lives. Because diabetes mellitus is not a single disease but rather a complex constellation of syndromes, each patient has a unique response to the disease process.
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Endocrinology A chronic condition which affects ±10% of the general population, characterized by ↑ serum glucose and a relative or absolute ↓ in pancreatic insulin production, or ↓ tissue responsiveness to insulin; if not properly controlled, the excess glucose damages blood vessels of the eyes, kidneys, nerves, heart Types Insulin dependent–type I and non-insulin dependent–type II diabetes Symptoms type 1 DM is associated with ↑ urine output, thirst, fatigue, and weight loss (despite an ↑ appetite), N&V; type 2 DM is associated with, in addition, non-healing ulcers, oral and bladder infections, blurred vision, paresthesias in the hands and feet, and itching Cardiovascular MI, stoke Eyes Retinal damage, blindness Legs/feet Nonhealing ulcers, cuts leading to gangrene and amputation Kidneys HTN, renal failure Neurology Paresthesias, neuropathy Diagnosis Serum glucose above cut-off points after meals or when fasting; once therapy is begun, serum levels of glycosylated Hb are measured periodically to assess adequacy of glucose control Management Therapy reflects type of DM; metformin and triglitazone have equal and additive effects on glycemic control Prognosis A function of stringency of glucose control and presence of complications. See ABCD Trial, Brittle diabetes, Bronze diabetes, Chemical diabetes, Gestational diabetes, Insulin-dependent diabetes, Metformin, MODY diabetes, Nephrogenic diabetes insipidus, Non-insulin-dependent diabetes mellitus, Pseudodiabetes, Secondary diabetes, Starvation diabetes, Troglitazone.
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.
To understand why insulin is important, it helps to know more about how the body uses food for energy. Your body is made up of millions of cells. To make energy, these cells need food in a very simple form. When you eat or drink, much of the food is broken down into a simple sugar called "glucose." Then, glucose is transported through the bloodstream to these cells where it can be used to provide the energy the body needs for daily activities.
People with diabetes either don't make insulin or their body's cells no longer are able to use the insulin, leading to high blood sugars. By definition, diabetes is having a blood glucose level of greater than or equal to126 milligrams per deciliter (mg/dL) after an 8-hour fast (not eating anything), or by having a non-fasting glucose level greater than or equal to 200 mg/dL along with symptoms of diabetes, or a glucose level of greater than or equal to 200 mg/dL on a 2-hour glucose tolerance test, or an A1C greater than or equal to 6.5%. Unless the person is having obvious symptoms of diabetes or is in a diabetic crisis, the diagnosis must be confirmed with a repeat test.
Complications of diabetes are responsible for considerable morbidity and mortality. The acute complications of diabetes are hypo- and hyperglycemic coma and infections. The chronic complications include microvascular complications such as retinopathy and nephropathy, and the macrovascular complications of heart disease and stroke. Diabetes mellitus is the commonest cause of blindness and renal failure in the UK and the USA. Other common complications include autonomic and peripheral neuropathy. A combination of vascular and neuropathic disturbances results in a high prevalence of impotence in men with diabetes. Peripheral neuropathy causes lack of sensation in the feet which can cause minor injuries to go unnoticed, become infected and, with circulatory problems obstructing healing, ulceration and gangrene are serious risks and amputation is not uncommon. Evidence from meta-analysis of studies of the relationship between glycemic control and microvascular complications (Wang, Lau, & Chalmers, 1993), and from the longitudinal multicenter Diabetes Control and Complications Trial (DCCT) in the USA (DCCT Research Group, 1993), have established a clear relationship between improved blood glucose control and reduction of risk of retinopathy and other microvascular complications in insulin-dependent diabetes mellitus (IDDM). It is likely that there would be similar findings for noninsulin-dependent diabetes mellitus (NIDDM) though the studies did not include NIDDM patients. However, the DCCT included highly selected, well-motivated, well-educated and well-supported patients, cared for by well-staffed diabetes care teams involving educators and psychologists as well as diabetologists and diabetes specialist nurses.
While many experts believe that most type 1 genes have been identified, the situation with type 2 diabetes is much different. A recent study found that the known genetic links to type 2 probably account for only about 6 percent of the genetic predisposition for that form of diabetes. This could mean either that some of the genes discovered have a bigger effect than is currently believed or that "we are still missing 94 percent of the genes," says Atul Butte, MD, PhD, an assistant professor of pediatrics at Stanford University.
Aspirin should be used as secondary prophylaxis in all diabetic people with evidence of macrovascular disease, and it should be strongly considered as primary prevention in diabetic subjects with other risk factors for macrovascular disease, such as hypertension, cigarette smoking, dyslipidemia, obesity, and albuminuria (macro or micro).228 Because of the platelet defects associated with diabetes, it is recommended that the dose of aspirin should be 300 mg per day,228–230 although the American Diabetes Association’s position statement (http://www.diabetes.org/DiabetesCare/supplement198/s45.htm) advocates a dose of 81 to 325 mg enteric-coated aspirin per day. If the patient cannot tolerate aspirin, then clopidogrel231 can be used.
According to the Mayo Clinic, your risk of developing type 2 diabetes increases as you age. Your risk goes up after age 45 in particular. However, the incidence of type 2 diabetes is increasing dramatically among children, adolescents, and younger adults. Likely factors include reduced exercise, decreased muscle mass, and weight gain as you age. Type 1 diabetes is usually diagnosed by the age of 30.
Diabetes mellitus is a chronic disease for which there is treatment but no known cure. Treatment is aimed at keeping blood glucose levels as close to normal as possible. This is achieved with a combination of diet, exercise and insulin or oral medication. People with type 1 diabetes need to be hospitalized right after they are diagnosed to get their glucose levels down to an acceptable level.
In type 2 diabetes, there also is a steady decline of beta cells that adds to the process of elevated blood sugars. Essentially, if someone is resistant to insulin, the body can, to some degree, increase production of insulin and overcome the level of resistance. After time, if production decreases and insulin cannot be released as vigorously, hyperglycemia develops.
Maturity onset diabetes of the young (MODY) is a rare autosomal dominant inherited form of diabetes, due to one of several single-gene mutations causing defects in insulin production. It is significantly less common than the three main types. The name of this disease refers to early hypotheses as to its nature. Being due to a defective gene, this disease varies in age at presentation and in severity according to the specific gene defect; thus there are at least 13 subtypes of MODY. People with MODY often can control it without using insulin.
Type 2 diabetes usually has a slower onset and can often go undiagnosed. But many people do have symptoms like extreme thirst and frequent urination. Other signs include sores that won't heal, frequent infections (including vaginal infections in some women), and changes in vision. Some patients actually go to the doctor with symptoms resulting from the complications of diabetes, like tingling in the feet (neuropathy) or vision loss (retinopathy), without knowing they have the disease. This is why screening people at risk for diabetes is so important. The best way to avoid complications is to get blood glucose under control before
Viral infections may be the most important environmental factor in the development of type 1 diabetes mellitus,  probably by initiating or modifying an autoimmune process. Instances have been reported of a direct toxic effect of infection in congenital rubella. One survey suggests enteroviral infection during pregnancy carries an increased risk of type 1 diabetes mellitus in the offspring. Paradoxically, type 1 diabetes mellitus incidence is higher in areas where the overall burden of infectious disease is lower.
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.
Creatinine is a chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Creatinine has been found to be a fairly reliable indicator of kidney function. As the kidneys become impaired the creatinine level in the blood will rise. Normal levels of creatinine in the blood vary from gender and age of the individual.
Insulin is a hormone that is produced by specialized cells (beta cells) of the pancreas. (The pancreas is a deep-seated organ in the abdomen located behind the stomach.) In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases more insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels after a meal. When the blood glucose levels are lowered, the insulin release from the pancreas is turned down. It is important to note that even in the fasting state there is a low steady release of insulin than fluctuates a bit and helps to maintain a steady blood sugar level during fasting. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range. As outlined above, in patients with diabetes, the insulin is either absent, relatively insufficient for the body's needs, or not used properly by the body. All of these factors cause elevated levels of blood glucose (hyperglycemia).
Classic symptoms of DM are polyuria, polydipsia, and weight loss. In addition, patients with hyperglycemia often have blurred vision, increased food consumption (polyphagia), and generalized weakness. When a patient with type 1 DM loses metabolic control (such as during infections or periods of noncompliance with therapy), symptoms of diabetic ketoacidosis occur. These may include nausea, vomiting, dizziness on arising, intoxication, delirium, coma, or death. Chronic complications of hyperglycemia include retinopathy and blindness, peripheral and autonomic neuropathies, glomerulosclerosis of the kidneys (with proteinuria, nephrotic syndrome, or end-stage renal failure), coronary and peripheral vascular disease, and reduced resistance to infections. Patients with DM often also sustain infected ulcerations of the feet, which may result in osteomyelitis and the need for amputation.
It is recommended that all people with type 2 diabetes get regular eye examination. There is weak evidence suggesting that treating gum disease by scaling and root planing may result in a small short-term improvement in blood sugar levels for people with diabetes. There is no evidence to suggest that this improvement in blood sugar levels is maintained longer than 4 months. There is also not enough evidence to determine if medications to treat gum disease are effective at lowering blood sugar levels.
If you recognize any of the symptoms, contact your doctor immediately. A simple in-office test for sugar in the urine is used for diagnosis. If that test is positive, then a drop of blood from the fingertip will confirm diabetes. Every day, thousands of adults and children around the world are diagnosed, but many go undetected. Early diagnosis cannot prevent Type 1, but it can head off potentially devastating, even fatal, health concerns.
Some people who have type 2 diabetes can achieve their target blood sugar levels with diet and exercise alone, but many also need diabetes medications or insulin therapy. The decision about which medications are best depends on many factors, including your blood sugar level and any other health problems you have. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.
Different environmental effects on type 1 diabetes mellitus development complicate the influence of race, but racial differences are evident. Whites have the highest reported incidence, whereas Chinese individuals have the lowest. Type 1 diabetes mellitus is 1.5 times more likely to develop in American whites than in American blacks or Hispanics. Current evidence suggests that when immigrants from an area with low incidence move to an area with higher incidence, their rates of type 1 diabetes mellitus tend to increase toward the higher level.
Type 1 diabetes has some connection to your family genes, but that doesn't mean you'll get it if one of your parents had it. "Since not all identical twins get diabetes, we do think that exposure to an additional environmental factor may trigger an immune response that ultimately causes destruction of the insulin-producing cells of the pancreas," says Dr. Sarah R. Rettinger, an endocrinologist with Providence Saint John's Health Center in Santa Monica, California.
The word mellitus (/məˈlaɪtəs/ or /ˈmɛlɪtəs/) comes from the classical Latin word mellītus, meaning "mellite" (i.e. sweetened with honey; honey-sweet). The Latin word comes from mell-, which comes from mel, meaning "honey"; sweetness; pleasant thing, and the suffix -ītus, whose meaning is the same as that of the English suffix "-ite". 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.