LEARNING OUTCOME AND OBJECTIVES:  Upon completion of this continuing education course, you will demonstrate knowledge of evidence-based guidelines related to caring for patients with metabolic syndrome. Specific learning objectives to address potential knowledge gaps include:

• Describe the group of patient characteristics that make up metabolic syndrome.
• Discuss the causes and risk factors of metabolic syndrome, including comorbid conditions.
• Discuss how to recognize metabolic syndrome and diagnostic parameters.
• Outline management strategies for the treatment of metabolic syndrome.
• Explain recommended lifestyle changes for prevention of metabolic syndrome.

WHAT IS METABOLIC SYNDROME?

Metabolic syndrome (also called insulin resistance syndrome or syndrome X) is a preventable condition that reflects the modern world’s way of living—a sedentary lifestyle and overnutrition, resulting in excess adiposity. With the number of people who are overweight or obese around the world, the incidence of metabolic syndrome is increasing. One quarter of the developed world’s population is estimated to have this syndrome, including 3%–5% of children and adolescents, as well as about 1 in 3 adults in the United States (Anagnostics, 2023; NHLBI, 2022c; Noubiap et al., 2022).

A syndrome is a group of symptoms and physical findings that occur together and characterize a particular abnormality or condition for which a direct cause is not necessarily understood. The group of characteristics that make up metabolic syndrome include:

• Excess body fat, especially around the waist, defined as a waist circumference ≥40 inches in males and ≥35 inches in females
• Elevated serum triglycerides ≥150 mg/dL or on drug treatment to reduce triglycerides
• Low serum high-density lipoprotein (HDL) cholesterol, <40 mg/dL in males and <50 mg/dL in females, or on drug treatment for low HDL cholesterol
• Elevated blood pressure ≥130/85 mmHg or on drug treatment for hypertension
• Fasting plasma glucose ≥100 mg/dL or on drug treatment for elevated blood glucose

Having any three of these five criteria constitutes a diagnosis of metabolic syndrome and increases the risk of developing type 2 diabetes and heart disease (Meigs, 2023).

Causes and Risk Factors for Metabolic Syndrome

There are several causes for metabolic syndrome, and each affects the other. Some of the causes can be controlled; others cannot.

The major cause of metabolic syndrome is an individual’s weight, especially abdominal adiposity. These fat cells can raise levels of chemicals (fatty acids) that, in turn, can elevate levels of other chemicals and hormones affecting the way the body controls blood sugar levels. Additionally, the body may not respond well to the hormone insulin, affecting how much glucose muscles and organs absorb from blood. This is referred to as insulin resistance.

These two factors—free fatty acids and insulin resistance—can raise “bad” LDL cholesterol and lower “good” HDL cholesterol. Insulin resistance can raise blood pressure and blood triglyceride levels.

In addition, the immune system can cause the extra fat cells to produce chemicals that increase inflammation. This can result in atherosclerosis, a buildup of a waxy substance consisting of cholesterol, cellular waste products, calcium, and fibrin inside blood vessels. These “plaques” can rupture, break off, and obstruct blood vessels, culminating in a myocardial infarction or ischemic stroke. Inflammation can contribute to insulin resistance, high blood pressure, and heart and blood vessel diseases (NHLBI, 2022a).

Risk factors that can be controlled include:

• Lifestyle habits:
• Inactivity
• Unhealthy diet and large-sized portions
• Poor quality and inadequate amount of sleep
• Smoking
• Alcohol use
• Occupation (working long-term night shifts or on schedules that change or rotate, which increases risk of metabolic syndrome due to misalignment of circadian rhythm)

Risk factors that may not be possible to control include:

• Age
• Environment (e.g., low socioeconomic status)
• Family history or genetics (e.g., diabetes, metabolic syndrome)
• Other medical conditions or treatments:
• Overweight and obesity
• Chemotherapy
• Hormone changes related to polycystic ovary syndrome
• Nonalcoholic fatty liver disease, a contributor to diabetes pathophysiology
• Immune system skin issues such as psoriasis
• Sleep deprivation, obstructive sleep apnea, and circadian rhythm disorders
• Some medications for treatment of allergies, bipolar disorder, depression, HIV, and schizophrenia
• Sex
  (NHLBI, 2022a)

Comorbid Diseases Associated With Metabolic Syndrome

People with metabolic syndrome are at risk for a long list of health problems, including:

• Type 2 diabetes mellitus
• Carotid atherosclerosis, arterial aging, aortic stiffening, and vascular conditions, including stroke, peripheral vascular disease, and coronary artery disease
• Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis, which can lead to cirrhosis, liver failure, or liver cancer
• Gall bladder and kidney damage
• Endothelial dysfunction, vascular remodeling, and thrombosis, including deep vein thrombosis (DVT) and pulmonary embolism (PE)
• Pregnancy complications
• Erectile dysfunction
• Serious complications from infections
  (Alshammary et al., 2021; ALF, 2023; Stewart & Kline, 2020)