Childhood type 1 diabetes is an autoimmune disease. The immune system destroys the β cells in the pancreas, which produce insulin. At the onset of diabetes, antibodies are found in the blood against the β cells of the islets of Langerhans.
In children with type 1 diabetes, and in their families, other autoimmune diseases and antibodies to other organs are found more frequently than in the general population.
DIABETES AND AUTOIMMUNE DISEASES
The most frequent diseases concern:
- The thyroid: thyroiditis (malfunction of the thyroid gland)
- Intestine: gluten intolerance or celiac disease (lack of intestinal absorption linked to gluten intolerance).
More rarely :
- The skin: vitiligo (depigmentation of the skin in white patches)
- Hair: alopecia (loss of hair and other hair)
- The adrenals: adrenal insufficiency (malfunction of the adrenal gland)
- The stomach: Biermer’s anemia (vitamin B12 deficiency anemia, secondary to a lack of absorption)
Frequency of associations
Frequency of thyroiditis
Antithyroid antibodies, witnesses of autoimmune thyroiditis, are present in 20 to 40% of young people with type 1 diabetes:
- Much more frequently in girls than in boys;
- With a frequency that increases with age (up to about 25% in girls after puberty).
Hypothyroidism (failure of the thyroid gland to function) due to autoimmune thyroiditis occurs in 3-8% of children and adolescents with type 1 diabetes.
Hyperthyroidism (over-functioning of the thyroid gland) due to autoimmune thyroiditis is much more rarely associated with type 1 diabetes (although more common than in the general population).
Frequency of gluten intolerance (or celiac disease)
The frequency of celiac disease is about 5-10% in children and adolescents with type 1 diabetes, which is about 10 times more than in the general population.
Celiac disease can occur in young children, adolescents and adults. It is more common in children who have diabetes in the early years of life.
DIABETES AND THYROID
The thyroid is a gland located at the bottom of the anterior face of the neck. It manufactures thyroid hormones: thyroxin (or T4L), 3 iodo-thyronine or (T3L).
These hormones act in many places in the body, which gives them several roles:
- Maintain body temperature.
- Control how the body spends energy.
- Act on the muscles and the heart
- Act on growth (size)
Another gland, the pituitary gland, located at the base of the brain, secretes the thyroid stimulating hormone TSH (Thyroid Stimulating Hormone), which stimulates the production of thyroid hormones.
When thyroid hormones are produced in sufficient quantities, they in turn slow down the secretion of TSH. Thus, there is a permanent balance between TSH and thyroid hormones.
If the concentration of thyroid hormones in the blood is too low (hypothyroidism), the concentration of TSH in the blood increases. If the concentration of thyroid hormones in the blood is too high (hyperthyroidism) the concentration of TSH in the blood decreases.
Gland: Organ whose function is to produce chemicals including hormones.
Hormone: Chemical substance produced and secreted by an organ (endocrine gland), and transported by the blood to act on another organ: to stimulate or slow it down.
Positive antibodies, normal thyroid
Most often, while anti-thyroid antibodies are positive, the thyroid continues to function normally:
- Thyroid hormones and TSH are at normal levels.
- There is no need for treatment.
- Monitoring is necessary, at least once a year.
HYPERTHYROIDISM (GRAVES’ DISEASE)
Over activity of the thyroid gland is much rarer. It can manifest itself by the following signs:
- restlessness, insomnia, weight loss, increased heart rate, sweating, feeling hot;
- eye signs, goiter;
- thyroid hormones at high levels, and low TSH;
- positive TSH receptor antibodies.
Treatment in the form of tablets, 1 to 3 times a day, slows down the functioning of the thyroid and normalizes thyroid hormones within a few weeks. Regular checks are necessary, every month and then every three months. This treatment is usually given for several years.
The fairly frequent association of thyroiditis and type 1 diabetes, and the frequency of silent forms of thyroiditis, justify its screening:
- by looking for specific antibodies;
- at the time of diagnosis of type 1 diabetes, then every 1-2 years;
- or in the presence of symptoms suggestive of hypothyroidism or hyperthyroidism.
DIABETES AND GLUTEN INTOLERANCE OR CELIAC DISEASE
What is gluten intolerance or celiac disease?
The function of the intestine is to digest and then absorb food, to pass it into the bloodstream which distributes it to the body. The inner wall of the intestine (the mucous membrane) forms folds, the villi, which provide a very large surface for absorption.
Celiac disease is caused by the destruction of the villi in the small intestine (villous atrophy), which significantly decreases the absorption of food. This destruction of the villi is due to an autoimmune reaction to gluten.
Gluten is the protein (elastic) fraction of wheat (wheat, spelled). It is also found in foods to which flour or wheat starch are added.
Certain gluten proteins are responsible for the autoimmune reaction, in particular gliadins.
Barley and rye contain proteins similar to gliadins (hordein, secalins) which are also toxic. Foods composed of these cereals or their derivatives (flour, starches, flakes, bread, cookies, cakes) are also deleterious.
Rice, soybeans, corn, potatoes and buckwheat do not contain gliadins, and are therefore not toxic.
People with gluten intolerance cannot eat foods that contain it.
How to diagnose gluten intolerance or celiac disease?
In children and adolescents with diabetes, gluten intolerance is often diagnosed by systematic screening, in the absence of any symptoms. (This is referred to as a silent disease.)
Gluten intolerance is sought in the presence of certain symptoms, we speak of active celiac disease:
- slower growth;
- diarrhea, abdominal bloating, loss of appetite, vomiting;
- sometimes unexplained hypoglycemia;
- anemia (iron malabsorption), osteoporosis (calcium malabsorption).
The diagnosis is based on the presence in the blood of specific antibodies, the existence of villous atrophy on intestinal biopsy and the disappearance of symptoms and the normalization of the antibodies under a diet excluding gluten.
The relatively frequent association of gluten intolerance and type 1 diabetes, and the frequency of silent forms of gluten intolerance, justify screening for gluten intolerance by looking for specific antibodies (anti-endomysium , anti-transglutaminase), at the time of diagnosis of type 1 diabetes. Screening is then repeated every 1-2 years, especially during the first years after diagnosis of diabetes, or in the presence of symptoms suggestive of celiac disease .
The intestinal biopsy is performed during an esogastroduodenal fibroscopy, an examination which consists of passing a flexible endoscope through the mouth and then taking samples of the lining of the intestine using a small metal forceps (biopsy) .
The intestinal biopsy is the key examination, essential for the diagnosis, without which one cannot begin the gluten-free diet.
How to treat gluten intolerance?
The treatment of celiac disease is a diet excluding gluten from wheat, and toxic proteins from certain cereals (barley and rye) and their derivatives.
Rice, soybeans, corn, potatoes and buckwheat are allowed.
There are gluten-free products (pasta, bread, cakes, etc.) which allow you not to give up these foods. You have to be very vigilant in the choice of commercial food products, gluten can be present in direct form (flour, breadcrumbs, etc.) or in masked form (starch, modified starch, starch products, etc.). It is also necessary to check the composition of drugs, especially coated. The diet can cause problems in communities, holiday camps, canteens, restaurants …
An extension of long-term illness coverage allows partial reimbursement of gluten-free products.
The gluten-free diet is only effective if it is strictly followed:
Specific antibodies normalize within 1 to 2 years
Children or adolescents with diabetes and gluten intolerance should be monitored regularly by the diabetologist pediatrician (Gluten-free diet may require an adjustment of insulin doses) and if possible by a gastroenterologist pediatrician and by a dietician with experience in children and gluten intolerance.
The gluten-free diet should be followed at least throughout the growth.