Diabetes mellitus type 1

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(Redirected from Insulin-dependent diabetes mellitus)

**Diabetes mellitus type 1**
*Classifications and external resources*
ICD-10	E10
ICD-9	250.x1, 250.x3
OMIM	222100
DiseasesDB	3649
MedlinePlus	000305
eMedicine	med/546

Diabetes mellitus type 1 is a form of diabetes mellitus.

Type 1 diabetes (formerly known as "childhood" or "juvenile" diabetes or "insulin dependent" diabetes) is most commonly diagnosed in children and adolescents. The adult incidence of Type 1 is similar to that for children [1], which is one of the reasons for changing the preferred term. Many adults diagnosed with Type 1 have been misdiagnosed as Type 2 diabetics, which has partly accounted for the misconception of Type 1 as a disease of children.

The most important forms of diabetes are characterized by decreases in, or the complete absence of, the production of insulin (Type 1 diabetes), or decreased sensitivity of body tissues to insulin (type 2 diabetes). The most useful laboratory test to distinguish Type 1 from Type 2 diabetes is the C-peptide assay, which is a measure of endogenous insulin production since external insulin to date has included no C-peptide. Lack of insulin resistance, determined by a glucose tolerance test, would also be suggestive of Type 1. Many Type 2 diabetics still produce some insulin internally, and all have some degree of insulin resistance.

Diabetes mellitus
Types of Diabetes
Diabetes mellitus type 1 Diabetes mellitus type 2 Gestational diabetes Pre-diabetes: Impaired fasting glycaemia Impaired glucose tolerance
Disease Management
Diabetes management: •Diabetic diet •Anti-diabetic drugs •Conventional insulinotherapy •Intensive insulinotherapy
Other Concerns
Cardiovascular disease Diabetic comas: •Diabetic hypoglycemia •Diabetic ketoacidosis •Nonketotic hyperosmolar Diabetic myonecrosis Diabetic nephropathy Diabetic neuropathy Diabetic retinopathy Diabetes and pregnancy
Blood tests
Fructosamine Glucose tolerance test Glycosylated hemoglobin

1 Pathophysiology
2 Treatment
3 Prevalence
4 Curing Type 1 Diabetes
5 Further reading
6 Notes
7 External Links

[edit] Pathophysiology

Type I diabetes is usually an autoimmune disorder, in which the body's own immune system attacks the beta cells in the Islets of Langerhans of the pancreas, destroying them or damaging them sufficiently to reduce or eliminate insulin production. The autoimmune attack may be triggered by reaction to an infection, for example by one of the viruses of the Coxsackie virus family.

Some researchers believe that the autoimmune response is influenced by antibodies against cow's milk proteins. A large retrospective controlled study published in 2006 strongly suggests that infants who were never breast fed had twice the risk for developing Type 1 diabetes as infants who were breast fed for at least 3 months. The mechanism, if any, is not understood. [2] Research has not been able to establish a connection between autoantibodies, antibodies to cow's milk proteins, and Type 1 diabetes. [3] [4] [5]

A subtype of type 1 (identifiable by the presence of antibodies against beta cells) typically develops slowly and so is often confused with Type 2. In addition, a small proportion of Type 1 cases have the hereditary condition maturity onset diabetes of the young (MODY) which can also be confused with Type 2.

Vitamin D in doses of 2000 IU per day given during the first year of a child's life has been connected in one study in Northern Finland (where intrinsic production of Vitamin D is low due to low natural light levels) with a reduction in the risk of getting type I diabetes later in life (by 80%) [6]. Some suggest that vitamin D3 may be an important pathogenic factor in type 1 diabetes independent of geographical latitude [7].

Some chemicals and drugs specifically destroy pancreatic cells. Vacor (N-3-pyridylmethyl-N'-p-nitrophenyl urea), a rodenticide introduced in the United States in 1975, selectively destroys pancreatic beta cells, resulting in Type 1 diabetes after accidental or intentional ingestion. [8] Vacor was withdrawn from the U.S. market in 1979. Zanosar is the trade name for streptozotocin, an antibiotic and antineoplastic agent used in chemotherapy for pancreatic cancer, that kills beta cells, resulting in loss of insulin production. [9]

Other pancreatic problems, including trauma, pancreatitis, or tumors (either malignant or benign), can also lead to loss of insulin production.

[edit] Treatment

Main article: Diabetes Management

Currently, type 1 is treated with insulin replacement therapy, carbohydrate counting and careful monitoring of blood glucose levels using Glucose meters. Insulin delivery is also possible via an insulin pump, which allows continuous infusion of basal insulin for prolonged periods at preset levels, and the capability to program 'push doses' (i.e. boluses) of insulin as needed at meal times.

Insulin treatment must be continued indefinitely. Continuous glucose monitors are also available to alert the presence of dangerously high or low blood sugar levels. Experimental replacement of beta cells (by transplant) is being investigated in several research programs and may become clinically available in the future. Thus far, beta cell replacement has only been performed on persons over the age of 18.

[edit] Prevalence

About 5-10% of North American diabetics have type 1. The fraction of type 1 in other parts of the world differs; this is likely due to both differences in the rate of type 1 and differences in the rate of other types, most prominently type 2. Most of this difference is not currently understood. Variable criteria for categorizing diabetes types may play a part.

[edit] Curing Type 1 Diabetes

Although type 1 diabetes is not currently curable, there are several approaches being researched:

[edit] Pancreas transplantation

Main article: Pancreas transplantation

Pancreas transplants are not generally recommended because introducing a new, functioning pancreas to a patient with diabetes can have negative effects on the patient's normally functioning kidney. For patients with kidney failure, however, a pancreas transplant is a viable option.

[edit] Islet cell transplantation

Main article: Islet cell transplantation

Less invasive than a pancreas transplant, Islet cell transplantation is considered a very promising approach to curing type 1 diabetes. In one variant of this procedure, Islet cells are injected into the patient's liver, where they take up residence and begin to produce insulin. The liver is expected to be the most reasonable choice because it is more accessible than the pancreas and the Islet cells seem to produce insulin well in that environment. The patient's body, however, will treat the new cells just as it would any other introduction of foreign tissue: the immune system will attack the cells as it would a viral infection. Thus, the patient also needs to undergo treatment involving immunosuppressants, which reduce immune system activity. Recent studies have shown that Islet cell transplants have progressed to the point that 58% of the patients in one study were insulin independent one year after the operation.<ref>Mayo Clinic: "Islet cell transplant: Emerging treatment for type 1 diabetes", 2005.</ref>

[edit] Islet cell regeneration

Research undertaken at the Massachussetts General Hospital in Boston Masschussetts from 2001 and 2003 demonstrated a protocol to reverse type 1 diabetes in mice.<ref>Mass General Hospital: "Regeneration of insulin-producing islets may lead to diabetes cure", November 13, 2003.</ref> Three other institutions confirmed the protocol, and their results were published in the March 24, 2006 issue of Science (journal). A fourth study by the National Institutes of Health further confirmed the protocol's efficacy, and also sheds light on the biological mechanisms involved.<ref>Science: "Comment on Papers by Chong et al., Nishio et al., and Suri et al. on Diabetes Reversal in NOD Mice" November 24, 2006.</ref>

[edit] Artificial Pancreas

Main article: Artificial pancreas

[edit] Genetic engineering

Fat or muscle cells that do not normally make insulin might possibly have a human insulin gene inserted by genetic engineering. These "pseudo" islet cells are then transplanted into people with type 1 diabetes.

[edit] Immune modification

Shutting down the autoreactive T cells that attack beta islet cells, allowing the islet cells to regenerate. Denise Faustman is investigating this hypothesis at Mass General Hospital, in Boston.

[edit] Stem cells

Research is being done at several locations in which islet cells are grown from stem cells. As of now they have been transplanted into mice and rats with some success.