Obesity, Metabolic Syndrome, and Diabetes - Key Concepts

Flashcards to review obesity, metabolic syndrome, diabetes, and their interrelated mechanisms as discussed in the lecture notes.

What is metabolic syndrome and why is it described as a tree with many branches?

Metabolic syndrome is a cluster of interrelated conditions (insulin resistance, central obesity, dyslipidemia, hypertension, and hyperglycemia) with inflammation and oxidative stress as branches; addressing the root metabolic dysfunction is crucial to prevent downstream conditions like diabetes and cardiovascular disease.

Which measure is a key marker of central obesity and metabolic syndrome risk?

Waist circumference (central fat distribution).

What type of fat distribution is most strongly linked to metabolic syndrome and cardiovascular risk?

Visceral adiposity around the thoracic and abdominal organs.

What roles do inflammation and oxidative stress play in obesity-related metabolic syndrome?

Expanding adipose tissue promotes inflammatory cytokines and oxidative stress, driving insulin resistance and tissue damage that fuel progression to diabetes and cardiovascular disease.

Name adipose-derived and gut-derived satiety signals mentioned in the notes.

Leptin (adipose-derived satiety signal) and cholecystokinin (CCK, gut-derived satiety signal).

What is monogenic obesity and how does it differ from polygenic/epigenetic obesity?

Monogenic obesity is caused by a single gene alteration affecting appetite control; most obesity results from complex interactions of multiple genes and epigenetic/environmental factors.

What happens when insulin resistance develops, in terms of glucose and insulin levels?

Cells become less responsive to insulin; glucose uptake decreases, leading to higher blood glucose; the pancreas secretes more insulin (hyperinsulinemia) in an attempt to compensate.

How does visceral fat influence lipid profile and cardiovascular risk?

Increases risk via insulin resistance, higher triglycerides, lower HDL, and higher blood pressure.

What is oxidative stress, and how is it connected to aging and metabolic syndrome?

An excess of reactive oxygen species causing cellular damage; overwhelmed antioxidant defenses promote aging and age-related diseases; inflammation amplifies ROS effects.

Which vitamins are key antioxidants and what is special about them?

Vitamin C (powerful water-soluble antioxidant) and Vitamin E (powerful fat-soluble antioxidant); vitamins A and flavonoids also support antioxidant defenses.

What external factors can increase reactive oxygen species and inflammation?

UV light, ionizing radiation, air pollution, and smoking—all contributing to oxidative stress and tissue damage.

What is the role of macrophages in obesity-related insulin resistance?

Macrophages infiltrate tissues and release pro-inflammatory cytokines, worsening insulin resistance and increasing insulin demand on the pancreas.

Why is BMI used in obesity assessment, and what are its limitations?

BMI quantifies body fat and risk for related conditions; it does not capture fat distribution or lean mass and may misclassify individuals.

What is meant by central fat distribution and why is it clinically important?

Fat around the trunk/visceral region; higher risk for metabolic syndrome, insulin resistance, diabetes, and cardiovascular disease compared to peripheral fat.

How can metabolic syndrome affect long-term cardiovascular function?

Increased cardiac workload due to obesity and insulin resistance can lead to cardiomyopathy and heart failure; risk increases with sedentary lifestyle and hypertension.

What are the common criteria of metabolic syndrome (NCEP-style) mentioned, and the role of HDL?

Increased waist circumference, elevated triglycerides, elevated blood pressure, fasting glucose > 100 mg/dL; low HDL is a concern and higher HDL is protective.

Why is early intervention important when one criterion of metabolic syndrome is present?

Early intervention can prevent progression to full metabolic syndrome and downstream complications like diabetes, hypertension, and heart disease.

What is the relationship between aging and metabolic syndrome components such as adiposity and insulin sensitivity?

Aging is associated with more visceral fat, reduced basal metabolic rate, and gradually reduced glucose tolerance and insulin sensitivity, increasing metabolic risk, especially with inflammatory or environmental stressors.

Why is treating root causes rather than only symptoms emphasized in metabolic syndrome?

Addressing underlying insulin resistance and visceral adiposity can prevent multiple downstream conditions, not just isolated symptoms like high blood pressure or high glucose.

In what ways can lifestyle and environmental factors affect metabolic syndrome progression and outcomes?

Physical activity, stress, diet, smoking, air pollution, and inflammation influence insulin resistance, oxidative stress, and lipid/metabolic profiles, modulating disease trajectory.