Factor analysis of risk variables associated with low-grade inflammation

Area of Science:

• Cardiovascular Disease Research
• Inflammation Biology
• Preventive Medicine

Background:

• Chronic subclinical inflammation, marked by elevated C-reactive protein (CRP), is a predictor of atherothrombotic events.
• The underlying causes of low-grade inflammation are complex, with various interconnected conditions linked to increased CRP levels.

Purpose of the Study:

• To investigate the clustering of variables associated with elevated CRP using principal factor analysis.
• To identify distinct factors contributing to chronic, low-grade inflammation in individuals without known coronary disease.

Main Methods:

• Principal factor analysis was applied to data from 1435 subjects without known coronary disease.
• Variables analyzed included metabolic syndrome components, uric acid, liver enzymes, pulmonary function, smoking status, cardiorespiratory fitness, and high-sensitivity CRP.

Main Results:

• Factor analysis revealed three significant factors: a "metabolic factor" (BMI, glucose, HDL, triglycerides, blood pressure, uric acid), a cardiorespiratory factor (fitness, lung function, sex), and a "smoking" factor (smoking, age).
• All three identified factors were independently associated with high-risk CRP levels (>=3mg/L).
• A model incorporating these three factors demonstrated predictive ability for high-risk CRP comparable to a model with the original ten variables.

Conclusions:

• Metabolic perturbations, cardiorespiratory fitness, and smoking represent distinct and largely independent contributors to the pathophysiology of chronic, low-grade inflammation.
• Understanding these factors can inform strategies for managing inflammation and reducing cardiovascular risk.