The increased cholesterol also ‘’increases’’ the body weight PART 2
The level of cholesterol depends on cholesterol and the fat contents from alimentation, energy balance, reflected through body weight, age, physical activity, estrogen hormone level (in women) and genetic polymorphism (in both sexes).
When energy intake exceeds expenditure, the excess is stored in adipose tissue in the form of triacylglycerol or triglycerides. When the body fat content of triacylglycerol becomes excessive (BMI 30 or more), we talk about obesity. In some obese people the excessive accumulation of triglycerides takes place in other tissues than adipose tissue. Two of these tissues are skeletal muscles and liver. The increased content of triglycerides in the liver and muscles is due to, mostly, the output of excessive amounts of unesterified fatty acids in fat tissue.
In the presence of a suitable body weights, the normal levels of insulin are sufficient to suppress the triglyceride hydrolysis in the adipose tissue, and the release of fatty acids from unesterified adipose tissue is low. In obese people, the release of unesterified fatty acids is excessive and occurs a flooding of the skeletal muscle and liver with unesterified fatty acids. And when skeletal muscle is overloaded with triglycerides, the uptake in muscle cells of blood glucose, mediated by insulin, is altered. This condition is called resistance to insulin.
Also, when the liver is loaded with triacylglycerol, the hepatic metabolism is altered and the insulin action on liver is disturbed. As a result, occurs a overproduction of VLDL that leads to high concentrations of VLDL and, because LDL is a product of VLDL will increase the LDL cholesterol. In addition, the obesity is accompanied by a decrease in HDL blood concentrations.
Thus, obesity is responsible for the alterations of lipoprotein metabolism, particularly the main lipoproteins, VLDL, LDL and HDL.
Sustained physical activity prevents the accumulation of excessive quantities of triglycerides in adipose tissue. In addition, the increase of muscular metabolism, due to physical activity, consumes (burn) unesterified fatty acids, preventing their accumulation in the liver. In other words, the increased energy expenditure favorably modify lipoprotein, especially lowering VLD concentrations and increasing HDL.
Between 20 and 50 years, occurs a gradual increase of cholesterol serum concentrations by an average of 50 mg / dL (1,295 mmol / l). This increase may be related to weighted gaining
according to the mechanisms described above. But also in people who do not gain weight, with age, shows a rise in cholesterol. This is due to the LDL receptors activity diminish.
In menopause women there is a growing concentrations of serum cholesterol, largely due to lack of the hormone estrogen. It is known that estrogen stimulates the synthesis of LDL receptors and, after the menopause installation, the receptors activity decreases.
Finally, cholesterol concentrations variations are explained, in approximately 50% of the cases, through the genetic polymorphism. But instead of resign, just people with a genetic inheritance less happy should be more careful in terms of feeding, particular attention to the oxidized cholesterol and physical activity.
And what are the normal values? Total cholesterol should not exceed 150 mg / dl, LDL should be below 100 mg / dl, and HDL higher than 50 mg / dl.
Let’s not forget: increased cholesterol does NOT hurt, which is why many refuse to change their lifestyle, even if the advice comes from a doctor. I like to think that this is not the attitude of those who had the patience to read up here this material.