Why does my blood sugar rise even though I haven’t eaten anything?

Your fasting blood sugar is high even though you haven’t eaten anything? This phenomenon, often discovered during a blood test or monitoring of diabetesmay surprise. In the majority of cases, however, it is simply explained.

The blood sugar corresponds to the blood sugar level. We are talking about fasting blood sugar when measured after several hours without eating, usually in the morning. Contrary to popular belief, this blood sugar level is not stable: it depends on numerous internal mechanisms, independent of diet.

Even without food intake, the body produces glucose. The foie continuously releases sugar into the blood to provide energy to body cells, including the brain. This blood sugar regulation is essential for the proper functioning of the body. Result: a increased blood sugar can occur unrelated to a meal.

In the majority of cases, a healthy person does not experience a slight increase in blood pressure. blood sugar. These variations are most often silent. They are mainly observed in people with diabetes who regularly monitor their blood sugar levels in real time. They may also be found in certain people who are very attentive to their health, equipped with sensors or engaged in personal monitoring.

The people most bothered would especially be type 1 diabetics:

When the high fasting blood sugar is observed repeatedly, the main cause is a disorder of the regulation of glucose. In case ofinsulin resistancethe action ofinsulin becomes less effective: glucose remains in the blood instead of being used by the cells.

Over time, this can evolve into a type 2 diabetes. More rarely, hyperglycemia can reveal a type 1 diabeteswhich generally progresses more quickly and symptomatically.

In these situations, thehyperglycemia may become noticeable and cause symptoms, especially when the disease is uncontrolled. This may be the case in a person who has not yet been diagnosed or who neglects their care.

Some increases in blood sugar are physiological and occur in everyone, even without eating. They are generally mild and not noticeable or bothersome in a healthy person.

However, blood sugar elevations may be more pronounced and become symptomatic in diabetes, particularly in type 1 diabetes, which relies on precise and continuous insulin delivery. “These glycemic rises are then rapid and significant, unlike stable high blood sugar levels “on plateau”, which can reflect an insufficient dose of slow insulin or, in people on a pump, an unsuitable basal flow rate,” specifies the expert.

It corresponds to an increase in blood sugar levels in the morning hours, linked to a surge of hormones (cortisolgrowth hormone). In people with type 1 diabetes, this phenomenon is particularly visible thanks to glucose sensors.

According to the specialist, the insulin pump and especially now the “ closed loop » now make it possible to manage this problem much better: “the pump automatically adapts the delivery of insulin according to data from a sensor transmitted every 5 minutes”.

In type 2 diabetes, high blood sugar levels upon waking can sometimes be linked to insufficient carbohydrate intake the evening before: “This induces an increase in the production of glucose by the liver that insulin (produced by the pancreas or injected) will have difficulty slowing down, which explains higher blood sugar levels upon getting up,” explains the endocrino-diabetologist.

“Stress causes a release of adrenaline and cortisol which induce resistance to insulin, making it less effective,” explains Doctor Sylvie Picard. It is often said that these hormones are hyperglycemic.

On the other hand, intense sport can cause a transient increase in blood sugar levels.

They can alter the insulin sensitivity and lead to higher blood sugar levels.

When blood sugar levels remain above normal values, including fasting or outside of meals, we speak ofchronic hyperglycemia. It may go unnoticed at first, but sometimes ends up causing symptoms such as:

Ces symptoms translate a too much sugar in the blood chronically and should lead to consultation. A blood test measuring the fasting blood sugar is then often prescribed.

A fasting blood sugar normal is generally between 0.70 and 1.10 g/L. Beyond that, we talk aboutfasting hyperglycemiaespecially if the values ​​are repeated. Blood sugar levels around 1.26 g/L or more may suggest diabetes. It is not an isolated value that counts, but the repetition of results.

Note that certain situations favor a high blood sugar such as pregnancy (which can, in some women, be accompanied by gestational diabetes) , some drugs(notably corticosteroids) or even certain hormonal diseases.

In these cases, appropriate monitoring is put in place.

This is a common question, but the answer always depends on the cause. In case of high blood sugar :

The citronfor example, has no demonstrated effect on blood sugar nor on blood pressure. Certain food supplements or plants (chrome, cinnamon, fenugreek…) are sometimes mentioned, but the scientific evidence remains limited.

There is no point in trying to do lower your blood sugar before a blood test. A blood sugar level should reflect your actual state, and not be changed occasionally.

For all people with type 1 diabetes on a pump : an increase in glucose without food intake should alert you to a possible pump catheter obstruction (whether “tubular” or “pod”). If it malfunctions, insulin is no longer delivered, which can cause blood sugar levels to rise rapidly.

We talk aboutpotentially dangerous hyperglycemia when blood glucose levels above 250 mg/dL (2.50 g/L)particularly if it persists for several hours (more than 3 hours for the diabetologist) or does not respond to the usual corrections. At this level, the risk of acute complications increases, particularly if symptoms such as nausea, vomiting, abdominal pain or unusual fatigue appear. A ketoacidosis can then occur.