Chronic hyperglycemia is most often related to the development of diabetes. The symptoms of hyperglycemia may take time to become apparent. Hyperglycaemia should be managed as soon as possible to avoid the long-term complications of too much glucose in the blood.

1. What is high blood sugar?

Blood glucose is the name given to the concentration of glucose in the blood. Normally, blood glucose is between 0.7 g/l and 1.1 g/l in the fasting state. It should be below 1.4 g/l after a meal. In fact, blood sugar levels rise temporarily after a meal, only to fall rapidly afterwards. This is physiological hyperglycemia. Sometimes this hyperglycemia can become a chronic condition, and thus pathological. There are different causes for a chronic increase in the blood glucose concentration: e.g. Diabetes, taking certain medications. Chronic hyperglycemia must be controlled because, in the long term, excess glucose in the blood can lead to complications and impair the functioning of tissues and organs.

2. What are the symptoms of high blood sugar?

Chronic low blood glucose is asymptomatic, which can be particularly dangerous because many people are unaware that they have chronic high blood glucose. Above a certain level (which varies among individuals), chronic hyperglycemia can cause:

a strong thirst;
a very frequent urge to urinate and abundant urination;
a significant weight loss despite an increased appetite;
dizziness;
Significant fatigue.

3. What causes high blood sugar?

The main cause of pathological hyperglycaemia is diabetes. Normally, glucose enters the cells, where it is used to create energy. In diabetes, glucose can no longer enter the cells, or it has difficulty entering the cells. There are generally two types of diabetes, type I diabetes, called insulin-dependent, and type II diabetes, called non-insulin-dependent. In type, I diabetes, the cells of the pancreas that secrete insulin, the only hormone in the body capable of lowering blood sugar, are destroyed. As a result, blood sugar levels rise rapidly to high levels. This type of diabetes is caused by an autoimmune disease that affects young people in particular. In type II diabetes, the cells become less sensitive to insulin, and glucose, instead of entering the cell, ends up accumulating in the blood. Type II diabetes is a multifactorial disease, with many risk factors such as an unbalanced diet, genetic predisposition, tobacco or alcohol abuse, sedentary lifestyle, and overweight. Type II diabetes is the most common type of diabetes since 90% of diabetics are type II diabetics. There is another type of diabetes, which affects pregnant women and is called gestational diabetes. Generally, this type of diabetes is transient and does not last after delivery. Gestational diabetes can sometimes reveal a pre-existing type I or type II diabetes. Other pathologies can also induce chronic hyperglycemia, for example, hemochromatosis, lesions of the pancreas, or pancreatitis (inflammation of the pancreas). Severe stress can also raise blood sugar levels.

Another possible cause of hyperglycaemia is the prolonged use of certain medications such as corticosteroids, pentamidine, thyroid hormones or certain painkillers. Osmolar hypoglycaemia occurs when the blood glucose concentration is very high and is associated with dehydration: this type of hypoglycaemia can develop in a diabetic person who is not taking his or her medication when taking corticosteroids or diuretics.

4. When to consult in case of Hyperglycaemia?

Hyperglycaemia is silent and does not cause any symptoms, so it is important to check your blood sugar regularly. In the case of diabetes, symptoms of hyperglycemia or hypoglycemia should be reported. Diabetes screening should be done regularly in at-risk populations. These are people over 45 years of age with a risk factors such as:

- cardiovascular disease;
- a strong sedentary lifestyle
- obesity or being overweight;
- a history of diabetes in the family;
- a drug treatment that can induce Hyperglycaemia.

5. What tests should be done to diagnose hyperglycemia?

Hyperglycaemia is very easy to detect. Glucose is not usually found in the urine. Therefore, a simple urine test with a dipstick can detect the presence of glucose in the urine, which most often indicates hyperglycaemia. A blood test is used to determine the level of glucose in the fasting blood. If the patient has a fasting blood glucose level between 1.1 g/l and 1.26 g/l, the person is considered pre-diabetic. If the fasting blood glucose level exceeds 1.26 g/L on several occasions, then diabetes is diagnosed. To detect the onset of insulin resistance or to detect gestational diabetes, the physician may order a special test called an oral glucose tolerance test (OGTT). This test involves fasting a quantity of glucose and then studying (by taking blood samples every hour) the glucose level in the blood.

6. What are the possible complications of hyperglycemia?

Uncontrolled, chronic high blood sugar can have serious health consequences. Chronic high blood glucose can damage blood vessels. When large vessels such as blood vessels are affected, it is called macroangiopathy, when small tissue and blood vessels are affected, it is called microangiopathy. People with diabetes are at greater risk for cardiovascular disease. People with diabetes are also more likely to develop retinopathy (damage to the vessels in the retina), nephropathy (kidney disease) and foot damage. The most serious complication of Type I diabetes is ketoacidosis. In type I diabetes, which is called insulin-dependent, glucose cannot enter the cells to produce energy, so the cells produce ketone bodies to compensate for this lack of energy. Ketone bodies are small acidic molecules which, if they accumulate, can acidify the body in a very serious way. Untreated ketoacidosis can lead to coma and even death. Untreated gestational diabetes poses multiple risks to the fetus, including macrosomia, neonatal hypoglycaemia and hyperbilirubinemia.

7. What are the treatments for high blood sugar?

The treatment is different depending on the type of diabetes detected. In the case of type I diabetes, the lack of insulin must be compensated by regular subcutaneous injections of insulin. Two types of injections are used to regulate blood sugar: rapid insulin injection and ultra-slow insulin injection. An insulin pump can also be used. Blood sugar levels must be monitored regularly to avoid hyperglycemia or hypoglycemia. For type II diabetes, the treatment first involves weight loss, a balanced diet, stopping smoking and regular physical activity. Smoking cessation is essential to avoid increasing the risk of cardiovascular complications. Oral anti-diabetic drugs that control blood sugar may be prescribed, such as glucose-lowering sulfonamides or alpha-glucosidase inhibitors. Sometimes insulin therapy (insulin injection) may be prescribed, especially when blood sugar levels cannot be stabilized. The treatment of type I and type II diabetes also requires therapeutic education of the patient. Patients should be able to test themselves regularly, and thus achieve true self-monitoring of their blood sugar. When blood glucose exceeds 2.5 g/l, it is also important to monitor the presence of ketones in the urine (using test strips), and the physician should be consulted in case of a positive presence. If the hyperglycemia is too high, one should not hesitate to seek urgent medical attention. In pregnant women, blood sugar control is achieved through a special diet or insulin treatment.

8. How can hyperglycaemia be prevented?

Type II diabetes is a multifactorial disease. Certain measures can help reduce the risk of developing chronic hyperglycemia. These measures include:

adopting a balanced diet, without excess fats or carbohydrates: favouring fruits and vegetables, eating three meals a day, consuming adapted portions;
Regular and adapted physical activity: regular and adapted physical activity reduces the risk of suffering from type II diabetes by 30%;
Avoid alcohol consumption;
Stop smoking;
Fight against chronic stress, and take time to relax.

To prevent complications of diabetes, regular preventive medical examinations should be performed, for example: have a fundus examination every year, consult a pedicurist regularly to quickly take care of possible foot problems, and be followed very regularly by a cardiologist. Similarly, kidney function can be monitored in order to detect a kidney problem as soon as possible.

Source :

Fédération française des diabétiques (glycémie) ; Fédération française des diabétiques (hyperglycémie), Inserm (diabète de type II), Inserm (diabète de type I), HAS ; Diabète Occitanie ; Le Manuel MSD