There are numerous conditions linked to insulin resistance, affecting a variety of organs and bodily regions that may appear unrelated to one another. The underlying pathogenic processes are interconnected through complex relationships that unfold within the context of metabolism and its regulation.

In this section, Metabolic Syndrome (MetS) and dyslipidemia are discussed and examined in depth.

Metabolic Syndrome (MetS)

Metabolic syndrome (MetS) is defined as a cluster of metabolic abnormalities linked to insulin resistance, which serve as risk factors for the development of cardiovascular disease (CVD), diabetes, renal failure, and other conditions.

There are five predisposing factors, and a diagnosis of MetS is made when three of these five parameters are present simultaneously:

• Abdominal circumference (“waist circumference”) ≥ 102 cm in men and ≥ 89 cm in women
• Triglycerides ≥ 150 mg/dL
• Fasting blood glucose ≥ 100 mg/dL
• HDL (high-density lipoprotein) < 40–50 mg/dL
• Systolic hypertension > 135 mmHg

In 2002, in the United States, approximately 25% of adults over the age of 20—and up to 45% of adults over the age of 50—were affected by metabolic syndrome (MetS). It is estimated that between one-quarter and one-third of the global population suffers from metabolic syndrome, and that it is increasingly affecting children and adolescents as well.

The metabolic defects that characterize metabolic syndrome are linked to a chronic, low-grade inflammatory and pro-thrombotic state, which predisposes individuals to the development of atherosclerotic plaques.

The underlying causes of metabolic syndrome (MetS) are multiple and heterogeneous. Among the most common etiological factors are insulin resistance, an unbalanced diet, being overweight, genetic predisposition, and a sedentary lifestyle.

Individuals with metabolic syndrome often exhibit no symptoms. Given the absence of specific symptoms, it is therefore essential to pay close attention to the various risk factors that may predispose a person to developing this syndrome.

Dyslipidemia

The term dyslipidemia refers to any significant abnormality in the lipids present in the blood.

This condition exposes an individual to an increased risk of developing cardiovascular diseases, including angina, myocardial infarction, intermittent claudication, and stroke.

Dyslipidemias represent a group of lipid profile alterations that, unfortunately, affect a large portion of the population. In the United States, for instance, a survey conducted between 2003 and 2006 revealed that approximately 53% of adults exhibit lipid abnormalities.

Dyslipidemias can be classified as follows:

• Hypercholesterolemia: high cholesterol levels
• Hypertriglyceridemia: high triglyceride levels
• Hyperlipidemia: high levels of both cholesterol and triglycerides

In most cases, dyslipidemia is a complex condition resulting from the interaction of various genetic and environmental factors, which combine in different ways from one person to another.

Depending on the underlying causes, dyslipidemias can be classified into two categories: primary (genetic) forms, which are more common in children, and secondary (acquired) forms, which are more prevalent in adults and the elderly—often stemming from poor lifestyle choices and dietary habits, such as a sedentary lifestyle and excessive caloric intake.

There is a strong correlation between dyslipidemia and insulin resistance; the latter is considered a secondary risk factor that can play a significant role in the development of these lipid abnormalities.

Furthermore, dyslipidemia presents no specific symptoms of its own. It is, in fact, a "silent" condition, remaining undetected until it leads to the development of diseases affecting target organs.

Remedies

We know that poor diet, being overweight, and a lack of physical activity are predisposing factors for the development of the conditions discussed here. It is therefore easy to understand why regular physical exercise and a proper, balanced diet are highly effective and recommended approaches for maintaining a healthy energy metabolism, preventing the onset of insulin resistance, and—consequently—avoiding the low-grade chronic inflammation that underlies many diseases.

In addition to correcting poor habits and adopting a healthy lifestyle, one may also consider the use of certain substances as dietary supplements. These include myo-inositol, magnesium, folic acid, and ferulic acid.