Coeliac Disease & Type 1 Diabetes
Diabetes is a condition where there is too much glucose (sugar) in the blood (hyperglycaemia). The pancreatic hormone insulin is responsible for the transport of glucose from the blood to the body’s cells where it is used as a vital source of energy. In those with diabetes, either insufficient insulin is produced by the pancreas, or the insulin produced does not work properly. The classic symptoms of diabetes include: a lack of energy, excessive urine production, thirst, and unexplained weight loss.
Types of diabetes
There are two main forms of diabetes: type 1 and type 2 diabetes.
Type 1 diabetes is an autoimmune disease where the ß-cells in the pancreas responsible for producing insulin are destroyed. Type 1 diabetes usually develops before the age of 30, with 50% of individuals diagnosed before the age of 16. Treatment of type 1 diabetes involves insulin replacement via injection or insulin pump therapy, regular carbohydrate containing meals and snacks, and frequent monitoring of blood glucose levels. Those with type 1 diabetes have an increased risk of also having coeliac disease.
In those with type 1 diabetes, the excess glucose in the blood is passed into the urine (glycosuria). This increases the amount of urine produced (polyuria). Excessive urination leads to increased thirst to replace the lost fluid. In addition, as the body is unable to access the glucose to use as energy, it turns to its fat and protein stores (muscle) as alternative energy sources. This use of fat stores as a metabolic fuel may result in ‘ketoacidosis’. If untreated, this will lead to coma and eventual death.
Type 2 diabetes is more common than type 1 diabetes (although incidence of both is increasing). It is an ‘insulin-resistant’ form of diabetes where insulin is still produced but in an ineffective form and/or in smaller amounts. There is a genetic basis to this disease and its development is closely linked with obesity. It most commonly develops in people over the age of 55, but with rising levels of obesity in the population, it is becoming increasingly common in younger adults and even children. Diet and lifestyle changes may be sufficient to control the disease, but most patients will also require oral medication. Eventually, some people may need to have insulin injections. There is no link between coeliac disease and type 2 diabetes, however it is possible for both of these conditions to occur in the same person but independent of each other.
Note: There is a third type of diabetes that is important to discuss in relation to coeliac disease. Latent autoimmune diabetes in the adult (LADA) is also an autoimmune diabetes that usually appears in adult life instead of childhood (as in type 1 diabetes). LADA is also known as ‘type 1.5 diabetes’. LADA is associated with coeliac disease in the same way and to the same degree as type 1 diabetes through HLA DQ2 and DQ8. Autoimmune diabetes (type 1 diabetes and LADA) is distinguished from type 2 by the presence of islet autoantibodies and HLA DQ2/8.
How is type 1 diabetes related to coeliac disease?
If a person has one autoimmune disease, they are at an increased risk of developing another. As many as 10% of children and adolescents with type 1 diabetes also develop coeliac disease.
Diagnosing type 1 diabetes
To test for type 1 diabetes, your doctor will assess your blood glucose levels and test your urine for glucose and ketones. High levels of glucose and ketones (in the blood and urine) are highly suggestive of type 1 diabetes. It is important not to delay the diagnosis of type 1 diabetes, as it can be life threatening if left untreated. If you suspect you have type 1 diabetes, speak to your doctor.
Treatment of type 1 diabetes
Type 1 diabetes is a lifelong condition for which there is currently no cure. The management of type 1 diabetes involves insulin replacement via frequent daily injections or insulin pump therapy, regular blood glucose monitoring along with the right balance of healthy food choices and physical activity. If coeliac disease also develops, a gluten free diet is required as well. It is important to consider the amount and type of carbohydrate consumed. Management is a team affair. Regular medical consultations with your family doctor and/or specialists (usually endocrinologist and gastroenterologist or paediatrician), diabetes educator and dietitian are important for managing the conditions. The aim of treatment is good blood glucose (glycemic) control. A number of factors can influence glucose levels e.g. insulin injections, diet, exercise and illness. Poorly controlled coeliac disease can cause poor blood sugar control.
Consequences of type 1 diabetes
If type 1 diabetes is not managed appropriately, a number of consequences can result. Preventable complications of diabetes can cause unnecessary illness and sometimes death. If blood glucose levels are consistently too high (hyperglycaemia), this increases the risk of diabetes complications including: Diabetic retinopathy (which may lead to poor vision and sometimes blindness), Diabetic nephropathy (renal disease), Diabetic neuropathy (nerve damage which may affect the feet, legs or gastrointestinal tract) and cardiovascular disease. Tight control of blood glucose levels and regular diabetes complications screening is essential to reduce the risk of these complications.
Hypoglycaemia occurs when blood glucose levels fall below 4mmol/l. This can be the result of a missed or delayed meal, not consuming enough carbohydrate at the last meal, being more physically active than usual, too much insulin or alcohol (especially if consumed on an empty stomach). The signs of hypoglycaemia include sweating, shakiness, nausea, increased heart rate and irritability. If glucose levels continue to fall, brain function can be impaired, causing confusion, disorientation, slurred speech and increasingly disturbed and often aggressive behaviour. Eventually the person may become unconscious. A ‘hypo’ in the early stages is treated by eating some easily absorbed carbohydrate. If unconsciousness occurs, the person is extremely drowsy, unable to take direction and/or having a seizure, they must not be given anything by mouth. Glucagon should be injected and an ambulance called.
Those with diabetes should always carry suitable gluten free hypo food with them. However, should a hypo occur when no gluten free carbohydrate food is available, a gluten containing carbohydrate should be taken to treat the hypo. The danger associated with hypoglycaemia outweighs the immediate risk associated with gluten ingestion.