Insulin resistance

 

Insulin resistance, or insulin resistance, describes a situation where cells become less sensitive to this hormone. When liver, muscle and fat cells become insulin resistant; less glucose enters these cells and remains in the blood.

In response to insulin resistance, insulin-secreting pancreatic cells tend to produce more insulin (hyperinsulinemia) and may eventually become depleted. Insulin production then becomes insufficient and the blood glucose level becomes very high (hyperglycemia).

Causes and consequences of insulin resistance

Insulin resistance is favoured by physical inactivity and obesity; which often precedes the onset of type 2 diabetes. Before the onset of diabetes, blood sugar can be between 1.1 and 1.25 g/L. In women, hyperinsulinemia can affect their fertility because it stops hormone production.

Insulin resistance is a cardiovascular risk factor. Its prevention involves changing eating habits and lifestyles.

How does insulin resistance arise?

Produced by the pancreas, insulin's mission is to regulate the level of glucose (sugar) in the blood, promoting its entry into cells and its conversion into energy.

But an unhealthy lifestyle (sedentary lifestyle, bad eating habits, etc.) will promote an increase in cholesterol, overweight and obesity. An accumulation of fat around the waist (abdominal adiposity) will disrupt the role of insulin.

This phenomenon known as "insulin resistance" results in lower use of sugar by the body and therefore a higher level of blood sugar (glycemia). This rise in blood sugar levels overstimulates the pancreas, which increases insulin secretion to compensate. After several years of evolution, the pancreas becomes exhausted, glucose intolerance appears, and then type 2 diabetes.

This insulin resistance can be diagnosed by an increase in waist circumference. A simple seam meter would allow you to early detect a new enemy entity of your arteries and pancreas: syndrome X or metabolic syndrome.

What are the risks of insulin resistance?

A high level of sugar for several years will gradually hit the arteries and small blood vessels. The repercussions are then throughout the body:

• The heart: the coronary arteries are affected, which will lead first to a risk of angina pectoris and then of myocardial infarction;

• The eyes: diabetes is the main cause of blindness in France, following damage to the small arteries that supply the retina;

• The arteries: the risks are hypertension and arteritis, with amputation in the most severe cases;

• Nerves: decreased sensitivity and pain in the legs, we speak of neuropathy;

• The feet: there is a risk of ulceration and difficulty in healing;

• The kidneys: the risk is the development of chronic renal failure.

Prevention and treatment of insulin resistance

Dietary measures

In the case of overweight and, in particular, excess abdominal fat, any weight loss, even modest, is beneficial as it improves insulin sensitivity. In practice, there's no need to embark on a draconian diet that you won't be able to maintain in the long run. You should review your eating habits to make them healthier:

• Reduce the consumption of fast-acting sugars and fats (deli meats, butter, snacks, cream, cheese, etc.);

• Favor slow carbohydrates, giving prominence to whole grains;

• Consume lean proteins such as fish or white meats;

• Focus on dietary fibre, fruits and vegetables;

• Reduce alcohol consumption.

Regular physical activity

Maintaining muscle mass will increase blood flow, and muscles react better to insulin. In addition, when playing sports and even after the session, glucose is better transported and free fatty acids are more easily consumed. The ideal? Between 3 and 5 sessions of 30 minutes minimum per week. You have to go gradually, according to your abilities and always be in agreement with your doctor if you suffer from known pathologies.

Drug treatment

Drug treatment can complement the lifestyle and dietary measures. It is intended to reduce insulin resistance and treat diabetes. Corresponds to taking antidiabetic drugs (metformin, glitazones, etc.) orally or by injection.

A link between insulin resistance and metabolic syndrome

We talk about metabolic syndrome (also called syndrome X, insulin resistance syndrome, pluri-metabolic syndrome or "the deadly quartet", the deadly quartet) when a person has at least three of the following five parameters:

 

 

• Waist circumference > 102 cm in men and > 88 cm in women - to be modulated according to ethnicity;

• HDL cholesterol (good cholesterol) < 40 mg/dl in men and < 50 mg/dl in women (or undergoing treatment for excess cholesterol);

• Triglycerides > 150 mg/ dl (1.7 mmol/L) (or being treated for excess triglycerides);

• Fasting blood glucose > 1 g/dl (or undergoing treatment for diabetes);

• Blood pressure > 130-85 mm Hg (or being treated for hypertension).

This phenomenon becomes more frequent with age, in case of cardiovascular history, overweight, lack of physical activity, or smoking. In the United States, 22% of Americans over the age of 20 have this syndrome*. That number is even higher among Mexican Americans.

Towards new and more comprehensive management of the metabolic syndrome

Insulin resistance, hypertension, excess cholesterol, overweight. These phenomena are closely related. There are therefore twice as many lipid balance abnormalities and cases of hypertension in diabetic patients as in the general American population. As such, the metabolic syndrome reflects the onset of insulin resistance that affects the entire body, with a particular acceleration of atherosclerosis and cardiovascular complications. Far from being insignificant, the overall mortality at 7 years is 18% in the case of metabolic syndrome associated with type 2 diabetes, against 4.6% if it is absent.