What are the key principles and recommendations for a comprehensive approach to preventive medicine in a general adult population?

Preventive Medicine and Principles of Screening: A Comprehensive Lecture Framework

Core Foundation: Lifestyle as Primary Prevention

The most effective preventive strategy is promoting healthy lifestyle behaviors throughout life, beginning as early as age 20, with pharmacotherapy reserved only for those at sufficiently high cardiovascular risk. 1

The Six Pillars of Lifestyle Medicine

• Nutrition: Emphasize vegetables, fruits, nuts, whole grains, lean protein, and fish while minimizing trans fats, processed meats, refined carbohydrates, and sweetened beverages 2
• Physical Activity: Engage in at least 150 minutes per week of moderate-intensity activity or 75 minutes per week of vigorous-intensity activity, plus resistance training with 8-10 exercises, 1-2 sets, 10-15 repetitions at moderate intensity twice weekly 1, 2
• Weight Management: Target BMI 18.5-24.9 kg/m²; for overweight/obese individuals, achieve 10% body weight reduction in the first year through caloric restriction and increased expenditure 1, 2
• Tobacco Cessation: Complete avoidance of tobacco products and secondhand smoke exposure 1
• Stress Management and Restorative Sleep: Address psychological factors that impact cardiovascular health 3
• Positive Social Connections: Foster supportive relationships as part of comprehensive health promotion 3

Risk Assessment Framework

When to Begin Risk Stratification

Start cardiovascular risk assessment at age 20 with measurement of traditional risk factors (blood pressure, lipids, glucose, BMI, smoking status), repeating at least every 4-6 years if not on therapy. 1, 2

The 10-Year ASCVD Risk Calculation (Ages 40-75)

For adults aged 40-75 years, calculate 10-year ASCVD risk using race- and sex-specific Pooled Cohort Equations before initiating pharmacotherapy 1, 2. This creates four risk categories:

• Low risk: <5% 10-year risk
• Borderline risk: 5% to <7.5% 10-year risk
• Intermediate risk: ≥7.5% to <20% 10-year risk
• High risk: ≥20% 10-year risk 1

Critical caveat: Patients with clinical ASCVD or LDL-C ≥190 mg/dL automatically qualify for treatment without risk calculation 2. The risk score serves as the starting point for clinician-patient discussion, not the sole decision factor 1.

Risk-Enhancing Factors for Borderline/Intermediate Risk

When 10-year risk is uncertain (borderline or intermediate), consider these factors to guide treatment decisions 1:

• Family history of premature ASCVD
• Persistently elevated LDL-C ≥160 mg/dL
• Chronic kidney disease
• Metabolic syndrome
• Conditions specific to women (preeclampsia, premature menopause)
• Inflammatory conditions (rheumatoid arthritis, psoriasis, HIV)
• Ethnicity (South Asian ancestry)
• Persistently elevated triglycerides ≥175 mg/dL
• High-sensitivity C-reactive protein ≥2.0 mg/L
• Lipoprotein(a) ≥50 mg/dL
• Ankle-brachial index <0.9

Coronary Artery Calcium Scoring

For adults with borderline or intermediate risk where treatment decisions remain uncertain after risk-enhancing factor assessment, measure coronary artery calcium score to reclassify risk upward or downward as part of shared decision-making. 1, 2

A CAC score of zero supports deferring statin therapy (except in diabetes, family history of premature CHD, or cigarette smokers); a CAC score ≥100 Agatston units or ≥75th percentile for age/sex/race favors statin initiation 1.

Principles of Effective Screening

Essential Characteristics of Valid Screening

A screening test should only be implemented when 4:

1. The disease has significant morbidity/mortality impact on the population
2. Early detection improves outcomes compared to treatment at symptomatic presentation
3. The test has acceptable sensitivity and specificity to minimize false positives/negatives
4. The screening interval is appropriate to the natural history of disease
5. Treatment is available and acceptable to patients
6. Resources exist for follow-up of positive screens

The Total Risk Approach

Policy recommendations must emphasize total cardiovascular risk assessment rather than single risk factor management, with treatment intensity proportional to absolute risk. 1

This means lower treatment thresholds for higher-risk patients and avoiding overtreatment of low-risk individuals with isolated borderline risk factors 1.

Pharmacotherapy Decision Framework

Blood Pressure Management

Target blood pressure <130/80 mm Hg for most patients requiring pharmacologic therapy, but initiate nonpharmacological interventions for all adults with elevated blood pressure or hypertension. 2

For stage 1 hypertension (BP 130-139/80-89 mm Hg), categorize patients as <10% or ≥10% 10-year ASCVD risk to determine need for immediate pharmacotherapy versus lifestyle modification alone 1.

Lipid Management with Statins

High-intensity statin therapy (targeting ≥50% LDL-C reduction) is recommended for secondary prevention in patients ≤75 years with clinical ASCVD. 2, 5

For primary prevention 2:

• Diabetes (ages 40-75): Moderate-intensity statin
• LDL-C ≥190 mg/dL: High-intensity statin regardless of risk score
• 10-year ASCVD risk ≥7.5%: Moderate- to high-intensity statin after clinician-patient discussion
• 10-year ASCVD risk 5-7.5%: Consider moderate-intensity statin if risk-enhancing factors present

Critical safety consideration: Statins carry risk of myopathy/rhabdomyolysis, particularly with age ≥65 years, renal impairment, hypothyroidism, and drug interactions (especially cyclosporine, gemfibrozil, certain antivirals) 5. Instruct patients to report unexplained muscle pain, tenderness, or weakness immediately 5.

Diabetes Management

Initiate lifestyle changes (diet and exercise) first, followed by metformin as first-line pharmacologic therapy, targeting fasting plasma glucose ≤110 mg/dL or HbA1c ≤7%. 1, 2

For patients with additional ASCVD risk factors requiring glucose-lowering therapy despite metformin, consider SGLT-2 inhibitor or GLP-1 receptor agonist 2. Treat other risk factors more aggressively in diabetics (BP goal 130/80 mm Hg, LDL-C goal <100 mg/dL) 1.

Aspirin for Primary Prevention

Use aspirin infrequently in routine primary prevention because bleeding risk generally outweighs ASCVD risk reduction. 2

This represents a significant shift from older guidelines—aspirin is no longer routinely recommended for primary prevention 2.

Age-Specific Screening Recommendations

Cancer Screening (Example: 51-Year-Old Female)

• Breast cancer: Annual mammography starting at age 40 6
• Cervical cancer: Every 2-3 years if three consecutive normal Pap tests 6
• Colorectal cancer: Starting at age 50, options include colonoscopy every 10 years, annual FIT/FOBT, flexible sigmoidoscopy every 5 years, CT colonography every 5 years, or double-contrast barium enema every 5 years 6

Cardiovascular Screening

• Blood pressure: Measure at every clinical visit 6
• Lipid panel: Every 5 years if normal 6
• Diabetes screening: If BMI ≥25 kg/m² or other risk factors present 6

Additional Considerations

For women with risk factors (early menopause, low body weight, family history, corticosteroid use), consider osteoporosis screening before age 65. 6

The Clinician-Patient Risk Discussion

Before initiating any pharmacologic therapy, engage in shared decision-making that addresses potential for ASCVD risk reduction, adverse effects, patient preferences and values, and presence of risk-enhancing factors. 2

This discussion should 1:

• Quantify absolute risk reduction expected from treatment
• Explain number needed to treat
• Discuss medication side effects and monitoring requirements
• Incorporate patient's health goals and concerns
• Reassess at regular intervals

Implementation Strategy: Team-Based Care

Establish practice-based systems for risk factor monitoring, reminders, and support services, with reimbursement structures that support preventive encounters. 1

Effective prevention requires 1:

• Collaboration between governments, national societies, and foundations
• Education and training programs for health professionals
• Assessment of achievement of lifestyle, risk factor, and therapeutic targets
• Integration of prevention into daily clinical practice

Population-Level Approaches

While individual risk assessment guides clinical decisions, population-wide interventions remain foundational 1:

• Tobacco use reduction policies
• Reduction of saturated fat and salt in processed foods
• Promotion of fruit and vegetable consumption
• Environmental supports for physical activity
• Economic and policy supports for healthy behaviors

Common pitfall: Focusing exclusively on individual clinical interventions while neglecting population-level strategies that create environments supporting healthy choices 1.

Reassessment and Monitoring

Reassess cardiovascular risk every 4-6 years in adults not receiving statin therapy, and continuously monitor achievement of lifestyle and risk factor targets in those receiving treatment. 2

Even when pharmacotherapy is prescribed, lifestyle goals must be emphasized at every visit 1. Prevention is not a one-time intervention but requires lifetime engagement between providers and patients 1.