Diabetes mellitus

How is it diagnosed?

Insulin is produced in the pancreas and regulates blood sugar. Normally, the upper limit of fasting venous blood glucose is 100 mg/dl, and the upper limit of postprandial blood glucose is 140 mg/dl.

Prediabetes (“hidden diabetes”) is diagnosed when fasting blood glucose is 100–125 mg/dl or postprandial blood glucose is 140–199 mg/dl. Diabetes mellitus is diagnosed when:

• fasting blood glucose is 126 mg/dl or higher;
• blood glucose 2 hours after a 75 g oral glucose tolerance test is 200 mg/dl or higher;
• blood glucose measured at any time of day is 200 mg/dl or higher;
• HbA1c (average blood sugar over the past 3 months) is above 6.5%.

Symptoms

When blood sugar is high, the body loses a lot of water, and sugar along with it. Because the body cannot use sugar as a source of energy, it starts to burn its own fat reserves, and as a result the patient loses weight.

Drinking a lot of water, frequent urination and unexplained weight loss despite eating a lot are also commonly regarded as signs of diabetes. The most frequent symptoms are:

• dry mouth and thirst (polydipsia);
• frequent urination (polyuria);
• hunger and overeating;
• weight loss;
• tiredness, fatigability and weakness;
• slow wound healing;
• fungal infections of the skin and, in women, of the vaginal area.

Types of diabetes

Depending on the underlying cause, several types of diabetes are distinguished:

• type 1 — insulin-dependent diabetes;
• type 2 — non-insulin-dependent diabetes;
• gestational diabetes (diabetes in pregnancy);
• other specific types.

Type 1 diabetes

Type 1 diabetes involves absolute insulin deficiency, and in some cases no insulin is produced at all. In 90% of cases it is an autoimmune disease; the remaining 10% are associated with the destruction of pancreatic cells.

This type usually begins before the age of 30 and has three peaks: preschool age (6 years), adolescence (13 years) and early adulthood (20 years). Symptoms such as dry mouth appear suddenly. The patient’s weight is either normal or decreasing.

Without treatment, the patient may fall into a diabetic coma and die. In this situation the patient must be hospitalised, because without insulin and appropriate treatment the coma is fatal. Signs of coma:

• nausea and vomiting;
• abdominal or chest pain;
• weakness;
• shortness of breath;
• hot, dry skin;
• rapid heartbeat;
• acetone odour on the breath.

Type 2 diabetes

Type 2 diabetes is caused by insulin resistance or reduced insulin secretion. It is seen mostly in people over 30 who are overweight. Genetics play a major role: if both the mother and the father have diabetes, the children’s risk of diabetes rises by up to 38%.

The disease develops slowly and often causes no complaints at all. Some patients experience blurred vision, numbness in the hands and feet, leg pain, recurrent fungal infections or slow wound healing.

Without proper treatment, hardening of the arteries (atherosclerosis) develops with age, and cardiovascular disease leads to non-healing wounds and gangrene. Patients who remain untreated for a long time may develop eye problems, kidney failure resulting in uraemia, and death from coma.

Gestational diabetes

In some pregnant women, insulin resistance and a genetic predisposition lead to high blood sugar. This is called gestational diabetes. High blood sugar in the first weeks adversely affects the normal formation of the fetal organs and can lead to miscarriage and preterm birth.

Babies may be born with certain organ anomalies, predisposed to diabetes and with a high birth weight (over 4 kg). A large fetus, in turn, causes breathing and heart problems in the mother, as well as tears and bleeding during delivery.

Among women found to have high blood sugar during pregnancy, 10–15% are at high risk of developing type 2 diabetes within 10 years.

For this reason, blood sugar should be checked at a pregnant woman’s first visit to the doctor, and ideally a glucose tolerance test should be performed at 24–28 weeks of pregnancy. If diabetes is confirmed, appropriate monitoring and treatment are required.

Treatment

Diabetes treatment rests on three main pillars. Diet and exercise are important in both type 1 and type 2 diabetes.

Type 1 diabetes is treated with insulin. Insulins differ in duration of action and injection technique, and are selected individually for each patient. Medical nutrition is essential alongside insulin injections. The patient should be physically active, receive full diabetes education and be able to measure their own blood sugar at home (self-monitoring of blood glucose, SMBG).

People with type 2 diabetes can often keep their blood sugar under control for a long time with medical nutrition and physical activity alone. However, after some time medication may become necessary.

• Medical nutrition — 6 small meals a day: 3 main meals and 3 snacks.
• Physical activity — unless contraindicated, 20–30 minutes of supervised exercise every day or every other day.
• Drug therapy — oral medications or insulin. There are many medications for diabetes: your doctor chooses the one that suits you, and you should take it at the dose and times your doctor prescribes.

Why does blood sugar control matter?

All diabetes-related complications are caused by high blood glucose. Research shows that keeping blood sugar at or near normal levels can prevent complications or delay their onset. When blood sugar is under control, diabetes turns from a disease into a way of life — and that way of life depends on the type of diabetes.

Patients should measure their fasting and postprandial (2 hours after starting a meal) blood sugar at regular intervals, and treatment should be adjusted to the daily readings.

Blood sugar levels over the past 3 months can be assessed with the haemoglobin A1c (HbA1c) blood test. The ideal level is between 4% and 6%.

That is why it is important to stay under a doctor’s supervision and follow their recommendations. Persistently high blood sugar always leads to negative consequences. You may fool yourself by thinking “one sweet today won’t hurt” or “today’s workout can wait until tomorrow”, but you cannot fool your metabolism.

More than 371 million people worldwide live with diabetes. According to the International Diabetes Federation (IDF), more than 187 million people are still unaware that they have it — one in two people with diabetes does not know about their condition.

The wide spread of the disease also highlights the medical, social, economic and psychological problems it causes. For this reason, on the recommendation of the IDF and the World Health Organization (WHO), World Diabetes Day is observed every year on 14 November. In 2006 the WHO adopted a special declaration describing diabetes as a “serious chronic disease”.