Risk Factors for Atherosclerosis
The major modifiable risk factors for atherosclerosis are elevated LDL cholesterol, hypertension, cigarette smoking, and diabetes mellitus, with additional important underlying factors including obesity, physical inactivity, and atherogenic diet. 1, 2
Major Risk Factors (Direct Causal)
These are the primary drivers of atherosclerotic disease with established causal relationships:
Lipid-Related Factors
- Elevated LDL cholesterol - The most critical lipid risk factor 1
- Low HDL cholesterol (<35 mg/dL in children; <40 mg/dL in men, <50 mg/dL in women) - independently predicts cardiovascular events 3, 1
- Hypertriglyceridemia (>150 mg/dL fasting) - independent risk factor 1
- Primary hypercholesterolemia (LDL-C 160-189 mg/dL) 4
Blood Pressure
- Hypertension (>140/90 mmHg in adults; >95th percentile for age/sex/height in children) 3, 2
- Systolic blood pressure >140 mmHg is particularly important for stroke risk 5
Metabolic Factors
- Diabetes mellitus - confers risk equivalent to established cardiovascular disease 1, 2
- Metabolic syndrome - combination of increased waist circumference, elevated triglycerides, elevated blood pressure, elevated glucose, and low HDL-C 4
Tobacco
- Cigarette smoking - strongest association with aortic aneurysm (HR 3.56) and significant impact across all vascular territories 5, 6
Age
- Advancing age - men ≥55 years, women ≥65 years 2, 7
- Age reflects cumulative atherosclerosis burden rather than being directly causal 2
Underlying Risk Factors
These factors influence risk both directly and through effects on major risk factors:
- Obesity/overweight - BMI >95th percentile in children; BMI ≥30 kg/m² in adults 3, 4
- Physical inactivity - failure to achieve 150 min/week moderate-intensity or 75 min/week vigorous activity 3, 8
- Atherogenic diet - high saturated fat (>7% calories), high cholesterol (>200 mg/day) 3, 2
- Family history of premature CVD - males <55 years, females <65 years 7, 4
- Socioeconomic and psychosocial stress 2
Emerging Risk Factors
These have demonstrated associations but are not routinely included in risk prediction:
Lipid-Related
- Elevated lipoprotein(a) - ≥50 mg/dL or ≥125 nmol/L 4, 9
- Elevated apolipoprotein B - ≥130 mg/dL 4
- Remnant cholesterol and VLDL particles 10
Inflammatory and Thrombotic Markers
Renal Markers
- Chronic kidney disease - eGFR 15-59 mL/min/1.73 m² 4
- Microalbuminuria - 30-300 mg/24h, predicts cardiovascular events even below threshold values 1
Other Markers
Sex-Specific Considerations
Important sex differences exist in risk factor impact 5:
- LDL cholesterol shows stronger associations with total CVD in men (HR 1.47) than women (HR 1.20)
- Systolic blood pressure demonstrates stronger associations in women for ischemic heart disease (HR 1.36 vs 1.20 in men) and peripheral arterial disease (HR 1.49 vs 1.12 in men)
High-Risk Conditions
Certain conditions confer particularly elevated risk 4:
- Chronic inflammatory conditions - psoriasis, rheumatoid arthritis, lupus, HIV/AIDS
- Premature menopause - before age 40 years
- Pregnancy-associated conditions - preeclampsia, gestational diabetes
- High-risk race/ethnicity - South Asian ancestry
Clinical Implications
Risk factor clustering dramatically amplifies atherosclerotic risk 2. A patient with three major risk factors (elevated LDL, hypertension, smoking) has substantially higher absolute risk than someone with severe elevation of a single factor. For example, in ischemic heart disease, having all three risk factors increases risk 2.86-fold compared to none 5.
The evidence consistently demonstrates that multiple modest elevations in risk factors pose greater danger than a single severe elevation 2, emphasizing the importance of comprehensive risk assessment rather than focusing on individual parameters in isolation.