What is diabetes mellitus type 1?

In more than 95% of cases, type 1 diabetes mellitus is an autoimmune endocrinopathy, while in the remaining cases it is idiopathic. In this disease, the body recognises the insulin-producing beta cells of the pancreas as foreign and mobilises the immune system to destroy and eradicate these cells. This destruction process can last from a few months to a few years, but usually results in total insulin deficiency and an abnormal rise in blood sugar.


What are the causes of diabetes mellitus type 1?

The immune disorder that causes the destruction of beta cells is due to a combination of genetic and environmental factors. It appears that environmental factors trigger this autoimmune disorder in genetically predisposed individuals. Such environmental factors include viruses and various cytotoxic chemicals.


I have diabetes type 1. What is the chance of my child developing diabetes type 1?

The likelihood of children to develop diabetes mellitus type 1, if their mother has type 1 diabetes is 3%, while the corresponding risk of children developing diabetes type 1, if their father has type 1 diabetes, is 6%. Relatives of patients with diabetes type 1 are also at increased risk of developing diabetes type 1.


What age and gender are affected by diabetes?

Diabetes type 1 can occur at any age, but the peak of its incidence is between 4-6 years of age and in adolescence. Although most autoimmune diseases occur predominantly in women, diabetes type 1occurs equally in both sexes.


What is its impact in Greece?

The incidence of diabetes type 1 varies by country. In Greece the annual incidence of type 1 diabetes is 9 per 100,000 children aged up to 14 years.


What are the symptoms & signs of Diabetes Mellitus type 1?

The symptoms and signs result from the absence of insulin, which makes it impossible for the glucose to enter the cells, resulting in production of other forms of energy, such as the ketones, which in increased amounts can lead to coma and death. The most common symptoms and signs of type 1 diabetes are:

  • Polyuria (peeing more than usual)
  • Polydipsia (feeling vey thirsty)
  • Polyphagia (eating a lot) with weight loss
  • Nocturia (peeing more than usual, especially at night)
  • Weakness and fatigue
  • Recurrent blurred vision
  • Cramps
  • Sensory abnormalities
  • Infections
  • Asymptomatic presentation
  • Diabetic ketoacidosis coma

How is diabetes mellitus type 1 diagnosed?

Once a diagnosis of Diabetes Mellitus has been made, the clinician will need to differentiate the type of diabetes in order to treat it appropriately. However, this is not always easy, as the boundaries between diabetes Type 1 and Type 2 are not always clear. Differentiation is achieved by a combination of clinical presentation, physical examination and history, and is supported by the following tests:

  • Special Antibodies
  • Insulin
  • C-peptide

Diagnosis of co-morbidities

Once the type of Diabetes Mellitus has been determined, the diagnosis and treatment of metabolic co-morbidities such as hyperlipidaemia, obesity, fatty infiltration of the liver, and other autoimmune diseases (such as autoimmune thyroiditis), in the case of Diabetes type 1, should be done. In addition, assessment of the status of vital organs such as of the heart and kidneys but also assessment of the clinical status of the gingiva is very important. Finally, the patient’s psychological state and acceptance of the disease should also be investigated.


What is the treatment for diabetes mellitus type 1?

/ / / Pharmacological Treatment

> Insulin

The treatment of diabetes type 1 consists of replacing the deficient hormone insulin, in a way that mimics the normal function of the pancreas. To do this, the insulin administered must be coordinated with meals and physical activity, as close as possible to the normal mode of secretion. The latter is achieved by administering a combination of basal/bolus insulin. Insulin can be administered subcutaneously by injections, pens, or an insulin pump.

Basal insulin is a long-acting insulin that ensures that glucose levels are maintained at stable levels during fasting periods (night, between meals) and is administered by one subcutaneous injection of long-acting insulin daily or by continuous subcutaneous administration of rapid-acting insulin via a pump.

Bolus or pre-meal insulin is a fast-acting insulin that normalises the post-meal rise in glucose levels. It is administered before meals and the exact dose is determined by a combination of pre-meal glucose levels, the size and composition of the meal and expected activity.

>What is an insulin pump?

The insulin pump provides continuous subcutaneous infusion of rapid-acting insulin, as a basal insulin and bolus doses of rapid insulin before meals, via an infusion pump. The aim of this technology is to closely mimic the function of the pancreas and to provide greater flexibility and therefore a better quality of life. There are several types of pumps, some of which communicate with special devices for continuous recording of glucose levels.


> Monitoring Sugar Levels-Glycaemic Targets

To achieve physiological insulin replacement, the patient should regularly measure their blood glucose levels and adjust the insulin dose according to their glycaemic targets. This is done in 3 ways:

  1. Systematic recording of glucose levels by the patient. This is done by using glucometers at least 4 times a day: before meals and at bedtime, while additional measurements are needed before exercise and driving, in case of impending hypoglycaemia and during periods of illness.
  2. Continuous recording of glucose levels through special devices. A thin catheter is inserted under the skin and through a special sensor continuously records the blood sugar levels. Alert applications provide timely information for the correction of hypo- and hyperglycaemia.
  3. Haemoglobin A1c (HbA1c), which depending on the patient’s diabetes control should be measured every 3 to 6 months.

> Diet

A well-balanced, diet is a fundamental component of the treatment of diabetes type 1. The proportions of essential dietary components must be individualised. Generally, 45% of the calories in the diet of patients with Diabetes are made up of carbohydrates, 25% to 35% of fats and 10% to 35% of proteins. In addition, patients with Diabetes type 1 should be trained to calculate the carbohydrates in the foods they eat and the amount of insulin that corresponds to them. The latter varies considerably for each patient and should be determined by an endocrinologist.


> Exercise

Exercise is the third fundamental component of type 1 diabetes treatment. In addition to the known benefits, cardiovascular protection and weight maintenance are additional benefits of exercise for the patient with type 1 diabetes. The endocrinologist should educate the patient in adjusting the dose and timing of insulin in relation to exercise.


> Training of the patient with Type 1 Diabetes Mellitus

For a successful outcome of treatment, patient  training  is fundamental to understand the nature of the disease, the treatment regimen and its particularities, the patient’s glycaemic targets , how to adjust the insulin dose according to the circumstances (exercise, stress, hypoglycaemia), the calculation of carbohydrates, fat and protein in their meals, the proper use of the insulin pump, the correct injection technique, the rules of healthy eating and exercise, and the prevention of complications. This comprehensive knowledge helps the patient to accept his disease and consent to its treatment.


In our clinic we provide intensive training for the patients with Diabetes type 1 and design individualized insulin, diet and exercise regimens, aiming at the optimal treatment solution for each patient, safety and the best quality of life. At the first visit, the patient also receives a comprehensive follow-up plan with a specific schedule and goals.”

/ / / Surgical Treatments for Diabetes type 1

> What is pancreatic transplantation?

The goal of pancreas transplantation in patients with type 1 diabetes mellitus is to make patients independent of insulin injections, reduce complications and optimise their quality of life. Pancreas transplantation usually takes place at the same time with kidney transplantation in candidates with end-stage renal disease and type 1 diabetes; more rarely, pancreas transplantation is performed after kidney transplantation or alone. In all cases, patients receive immunosuppression lifelong to prevent graft rejection.


> What are the success rates of transplantation?

The 5-year graft survival, when the transplant is performed at the same time as the kidney transplant, is approximately 69% to 73%. While the 5-year graft survival, for pancreas transplantation alone is about 54%.


> Is there a transplantation only for islets of Langerhans?

Transplantation of pancreatic islets is under development and is currently only being carried out in experimental studies. Islets of Langerhans transplantation require lifetime immunosuppression, as well.


Complications of Diabetes Mellitus

/ / / Acute Complications of Diabetes Mellitus

> Hypoglycaemia

Hypoglycaemia is the most common complication seen in insulin-treated diabetics. Less commonly, it also occurs in diabetic patients taking drugs that stimulate pancreatic beta cells to secrete insulin, such as sulfonylureas. The lower normal limit of fasting glucose is 70 mg/dl. Below these levels, the body mobilises neuronal and hormonal mechanisms to prevent further drop in glucose levels ensuring normal brain function. The most important hormone that prevents the fall in blood sugar is glucagon. Unfortunately, over the years, diabetic patients gradually lose the protective mechanisms against hypoglycaemia. On the other hand, severe and repeated hypoglycaemia can lead to coma, irreversible brain damage or even death. The treatment of hypoglycaemia consists in ingestion of 15 g glucose, such as natural orange juice. In more severe cases, hospital admission may be needed. However, more important is the prevention of hypoglycaemia, which is achieved by proper training of the diabetic patient and compliance with the treatment.


> Diabetic Ketoacidosis/Hyperglycaemic Hyperosmolar State

These are the two most serious acute complications of diabetes, which if not treated in time can lead to death. They are characterised by severe hyperglycaemia, which lead to dehydration and metabolic acidosis. Both of these hyperglycaemic crises are due to a combination of relative or absolute insulin deficiency and a rise in stress hormones, which, however, antagonise the action of insulin and thus exacerbate hyperglycaemia. In the case of diabetic ketoacidosis, which usually occurs in patients with type 1 diabetes, the lack of insulin typically leads to the production of ketones, which further aggravate the metabolic acidosis The trigger point is usually a stressful situation, such as a severe infection, myocardial infarction or recent surgery. Many times these two emergencies lead to the first diagnosis of diabetes.


Similarly to hypoglycaemia, more important is the prevention of these complications, which is achieved by proper training of the diabetic patient and compliance with his/her treatment. In our practice, our experience at major diabetes centres abroad allows us to provide an intensive training regimen for patients with diabetes with a focus on the prevention and management of these serious acute complications of the disease.

/ / / Chronic Complications of Diabetes Mellitus

Diabetes is a multi-systemic disease that affects most organs of the body at different times of the diabetic patient’s life. However, diabetic vascular disease and neuropathy cause significant morbidity and mortality and therefore need thorough and systematic monitoring.


> What are and how can I prevent the macro-vascular complications of diabetes (Diabetic Vascular Disease)?

The macrovascular complications of diabetes involve the large vessels and are in fact an accelerated form of atherosclerosis, which is responsible for the increased rates of heart attacks, strokes and gangrene seen in diabetic patients. Indeed, diabetic patients have an increased risk of dying from one of these complications, collectively called atherosclerotic cardiovascular disease, and their life expectancy is 6-8 years shorter than the general population.


> Prevention/Treatment of Macro-Vascular Complications

An important part of the management of diabetes is therefore the prevention and/or treatment of macrovascular complications, which consists, apart from proper glycaemic control, in the treatment of the risk factors of atherosclerotic cardiovascular disease. These are obesity, hypertension, dyslipidaemia and smoking. In particular, patients with type 2 diabetes, at the time of diagnosis, already have one or more risk factors or are already suffering from one of the chronic complications of their disease. Addressing the risk factors of atherosclerotic cardiovascular disease has been shown to reduce cardiovascular mortality.


> What are and how can I prevent microvascular complications of diabetes (Diabetic Vascular Disease)?

Microvascular complications of diabetes involve the smaller vessels and primarily include diabetic ophthalmopathy and neuropathy.


> Can I lose my vision from diabetic ophthalmopathy?

Diabetic ophthalmopathy is one of the most serious causes of blindness worldwide. Its incidence reaches 75%-95% after 15 years of type 1 diabetes and reaches 60% after 15 years of type 2 diabetes. In addition, end-stage diabetic kidney disease develops in 40% of patients with type 1 diabetes, while this percentage is less than 20% in patients with type 2 diabetes.

“At least once a year all patients with type 2 diabetes and patients with type 1 diabetes of duration ≥5 should have their urinary albumin excretion tested”

“At least once a year all patients with type 2 diabetes and patients with type 1 diabetes of duration ≥5 should have an eye examination by an ophthalmologist”


> Prevention/Treatment of Microvascular Complications

The duration of diabetes and good glycaemic control are key risk factors of microvascular complications. Additional risk factors include hypertension, the presence of other microvascular complications, smoking, obesity, age and genetic factors. As with other complications of diabetes, their prevention is very important and involves a number of actions, such as systematic screening and addressing risk factors.

“Optimising blood sugar and blood pressure levels reduces the risk and slows the progression of diabetic nephropathy”

“Optimizing blood sugar, lipid (cholesterol) and blood pressure levels reduces the risk and slows the progression of diabetic retinopathy”


> Diabetic Neuropathy

Peripheral and autonomic neuropathy are the two most common complications of both type 1 and type 2 diabetes. Up to 50% of patients with type 2 diabetes develop diabetic neuropathy. Peripheral neuropathy involves the peripheral nerves and the most common form is the Distal Symmetric Polyneuropathy, characterized by progressive loss of sensation and mobility. The longer nerves are particularly sensitive and therefore the legs are most often affected. Unfortunately, up to 50% of patients are asymptomatic. If the disease is not diagnosed and treated in time, the patient is at increased risk of injuring their feet without realising it, due to the lack of sensation, and thus developing ulcers, which can eventually lead to amputation, with a significant reduction in the quality and life expectancy of patients. Prevention is therefore of paramount importance here, too.

“At least once a year all patients with type 2 diabetes and patients with type 1 diabetes of duration ≥5 should be screened for diabetic peripheral neuropathy”

“Optimizing blood sugar levels prevents or delays the development of neuropathy in patients with type 1 diabetes and slows the progression of neuropathy in patients with type 2 diabetes.”


> Autonomic Neuropathy

Autonomic Neuropathy is a common clinical problem in patients with diabetes as it can go unnoticed and can affect multiple organs, such as the blood pressure and pulse, gastrointestinal, bladder, and erectile function. Erectile dysfunction is closely associated with the onset of coronary heart disease as it precedes coronary heart disease by 3-5 years. Similarly, to other complications of diabetes, prevention is the best treatment.

”In our clinic, patients with diabetes mellitus follow a systematic follow-up program, where along with the glycaemic control, the complications of diabetes are thoroughly and systematically examined and treated, based on the international guidelines and our experience from the largest diabetes centres abroad.”