Primary Prevention of Chronic Diseases

Lecture 12 Topic: Primary prevention of chronic disease & Review for KHPM324 Chronic Diseases of Modern Society
Instructor: Hannah Oh, ScD
Affiliation: Division of Health Policy & Management, College of Health Sciences, Korea University

Midterm Exam: 10/22, 1:30 PM
- Duration: 1 hour (1:30-2:30 PM)
- Coverage: Content from Part 1 and Part 2
- Study Aid: Study guide available online
- Format: Multiple-choice, True/False, Short answer questions
- Location: Hana Science Building B128

Quiz Platform: Socrative.com
- Functionality: Student log-in for quizzes
- Room: Specific room designation not provided

**Definitions of Prevention:
- Tertiary Prevention:** Rehabilitation and management aimed at preventing complications of established disease.
- Secondary Prevention: Early detection and intervention through screening to halt disease progression.
- Primary Prevention: Preventing the onset of disease within high-risk populations to maintain health.
Prevention Stages:
- Reversible onset of disease through primary prevention.
- Disability and death arise from advanced symptoms, which are typically irreversible.

Outcome and Diseases:
- Cardiovascular Disease (CVD) leading to death, arrhythmias, heart failure, and stroke.
- Cognitive Decline also a potential consequence.
Categories of Risk Factors:
- Established Risk Factors:
- Dyslipidemia
- Hypertension
- Diabetes
- Inflammatory pathways
- Thrombosis
- Arrhythmic risk
- Adiposity
- Endothelial dysfunction
- Metabolic dysfunction
- Lifestyle Risk Factors:
- Poor dietary habits
- Physical inactivity
- Smoking

Major Risk Factors:
- Abdominal/Visceral fat (obesity)
- High intake of sugars and processed foods
- Physical inactivity and sedentary lifestyle
- Family history of diabetes
- High blood pressure
- Metabolic syndrome
- Inflammation
- Poor sleep habits

Optional Reading:
- Stampfer MJ, et al (2000) "Primary prevention of coronary heart disease in women through diet and lifestyle." N Engl J Med. 343: 16-22.

Data from Nurses' Health Study (1980-1994):
- Table Format:
- Factor | Relative Risk (95% CI) | Percentage in Each Category
  - Dietary Score:
  - 1: 1.90 (1.55-2.34)
  - 2: 1.50 (1.21-1.88)
  - 3: 1.57 (1.29-1.91)
  - 4: 1.23 (0.98-1.55)
  - 5: 1 (reference)
  - Exercise (hours per week):
  - <1.0: 1.41 (1.15-1.75)
  - 1.0-2.2: 1.23 (0.99-1.53)
  - 2.3-3.5: 1.18 (0.94–1.47)
  - 3.6-5.5: 1.05 (0.82-1.34)
  - >5.5: 1 (reference)
- Body-Mass Index (BMI):
  - ≥30.0: 1.57 (1.30-1.91)
  - 25.0-29.9: 1.33 (1.12-1.57)
  - 23.0-24.9: 1.16 (0.95–1.41)
  - <23.0: 1 (reference)
Smoking (cigarettes/day):
- >15: 5.48 (4.67-6.42)
- 1-14: 3.12 (2.50-3.90)
- Former smoker: 1.55 (1.31–1.82)
- Never smoked: 1 (reference)
Alcohol Consumption (g/day):
- 0: 1.65 (1.39-1.95)
- 0.1-5.0: 1.41 (1.18-1.68)
- 5.1-10.0: 1.26 (1.00 1.60)
- >10.0: 1 (reference)
Important Insight: The combination of lifestyle factors impacts the risks for coronary heart disease.
- Investigators noted clustering of healthful behaviors within individuals.

Definition:
- PAR assesses the public health impact of exposure in a population.
- It denotes the proportion of disease incidence in a population that can be attributed to a specific exposure.
- Essentially, it describes the disease incidence that could be eliminated if the exposure were removed.
Formula:
- PAR = \frac{Incidence{Population} - Incidence{Unexposed}}{Incidence_{Population}}

Comparative Example:
- Consider two populations (A and B), where:
- Population A Smoking Prevalence: 80%
- Population B Smoking Prevalence: 30%
- Question: Which population has a higher PAR?
Implication: Greater prevalence of an exposure within a population correlates to higher potential for associated disease events.

Each lifestyle risk factor correlates to increased coronary heart disease risk in a dose-response manner with notable emphasis on smoking as a strong contributor.
A healthful lifestyle can potentially prevent significant coronary disease events, with estimates indicating as much as an 82% prevention rate within the studied cohort.

Diabetes Explanation:
- A metabolic disorder that arises when the pancreas fails to produce sufficient insulin or the body cannot use insulin effectively.

Type 1 Diabetes:
- Rapid onset of symptoms
- Insulin therapy is crucial for survival
- Accounts for at least 90% of diabetes cases.
Type 2 Diabetes:
- Characterized by insulin resistance and/or relative insulin deficiency.

Normal Action:
- Signals liver to uptake glucose, stores as glycogen for later use.
- Signals fat cells to take up glucose for triglyceride storage, inhibiting fat breakdown.
- Supraliminal higher insulin levels prompt the liver to release stored glucose to ensure energy is available.

Diagram Explanation:
- Constant high glucose leads to high insulin levels which subsequently causes hunger and cravings due to starving cells.
Key Takeaway: Insulin receptors become resistant over time, leading to further complications of diabetes.

Waist Circumference Data:
- Age-adjusted relative risk (RR) based on waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI):
- A high WC correlates strongly to the risk of diabetes (RR=20.4), outperforming BMI (RR=16.5).

Findings:
- Both obesity and lack of physical activity are contributors to type 2 diabetes, with obesity presenting a more significant risk.
- Physical activity improves diabetes prevention but cannot offset the detrimental effects of obesity entirely.