Diabete di tipo 1
Type 1 diabetes (T1D) accounts for about 10% of all diabetes cases, formerly known as juvenile diabetes, and it is an autoimmune disease that originates when cells producing insulin (beta cells) are destroyed by the immune system.
T1D usually arises at a young age and can typically be distinguished from type 2 by testing for the presence of specific autoantibodies.
Pancreatic beta cells destruction generates a progressive lack of insulin, a hormone regulating glucose levels in the blood, which causes very high blood sugar (hyperglycemia), with polyuria (increased urination), polydipsia (increased thirst), and weight loss. Consequently, the only effective therapy of T1D is exogenous insulin.
The diagnosis of diabetes is based on fasting blood glucose above 126 mg/dl at least twice (normal blood glucose levels after 8 hours of fasting are below 100 mg/dl) or blood glucose above 200 mg/dl after an oral load of 75 grams of glucose.
Type 1 diabetes begins suddenly, and the typical symptoms are:
- need to drink frequently
- need to urinate more frequently than usual, especially at night
- feeling of tiredness
- weight loss and muscle mass
Symptoms of type 1 diabetes usually develop very quickly in young people (within a few days or weeks). In adults, type 1 diabetes is less frequent, and symptoms develop more slowly (a couple of months).
These symptoms occur due to a lack of insulin, causing glucose to not enter the cells and consequently both rise of its levels in the blood and cellular deprivation of such important source of energy. Excess glucose is eliminated in the urine and, hence, the person with diabetes urinates more often and, consequently, drinks more than usual.
T1D is caused by an alteration in the immune system that recognizes pancreatic insulin-producing beta cells (β-cells) as foreign thus producing autoantibodies causing cell death and lack of insulin production. The cause of the altered immune system response is not yet known: numerous studies have investigated possible viral, dietary or environmental factors without, to date, reaching solid conclusions on the causes of the disease. People with type 1 diabetes could have family members with diabetes, which suggests that the autoimmune phenomenon against pancreatic cells may have a genetic basis. A person with a close relative, such as a parent, brother or sister with type 1 diabetes, has an approximately 6% chance of developing the same disease. The risk for people who do not have family members with diabetes is just under 0.5%.
T1D occurs when insulin-producing cells have been destroyed by the immune system. However, even years before clinical manifestations, it is possible to detect certain auto- antibodies directed against beta cells in the blood. These auto-antibodies are: anti- pancreatic insulin (ICA), anti-decarboxylase of glutamic acid (GAD), anti-insulin (IAA), anti- tyrosine phosphatase (IA-2A) and anti-zinc transporter 8 (ZnT8).
Recent studies evidence that there is a first phase of T1D when auto-antibodies are present in the blood even though blood glucose levels still appear normal. The presence of any one of the four autoantibodies suggests that in 20% of cases one may develop T1D within 10 years, while the presence of two or more antibodies is associated with a risk of progression to diabetes more than 80% within 10 years. The absence of these autoantibodies indicates the substantial absence of risk for autoimmune T1D.
The treatment of type 1 diabetes is linked to the use of insulin, which is currently available in numerous formulations and with delivery devices that effectively facilitate the control of blood glucose levels.
Type 1 diabetes can cause major complications both acutely, especially in the onset phase when it has not yet been diagnosed, and chronically, i.e., over years, with damage to the heart, blood vessels, kidneys, eye and nerves.
For these reasons, it is crucial that diabetes is diagnosed as early as possible to quickly start treatment and to refer the person with diabetes to a specialized center for treatment and control of the disease. Read more on ISSalute
