---

1. CORONARY HEART DISEASE (CHD / Ischaemic Heart Disease)

---

a) Epidemiology

• CHD is the leading cause of death worldwide, accounting for ~16% of all deaths globally (WHO).
• Approximately 17.9 million people die from cardiovascular diseases each year; CHD contributes the largest share.
• More than 75% of CVD deaths occur in low- and middle-income countries.
• The Framingham Heart Study, INTERHEART study, and WHO MONICA project have been landmark epidemiological tools.

• India is experiencing an epidemiological transition; CHD now causes ~25-30% of all deaths.
• Prevalence of Ischaemic Heart Disease: approximately 37 per 1000 population (NPCDCS data).
• Indians develop CHD 5-10 years earlier than Western populations.
• Urban prevalence (8-12%) is higher than rural (2-4%), though the rural burden is rapidly rising.
• South Asians have a disproportionate genetic predisposition (higher Lp(a) levels, central obesity, metabolic syndrome).
• CHD is more common in men, but post-menopausal women rapidly approach male rates.

---

b) Risk Factors

NON-MODIFIABLE Risk Factors

MODIFIABLE Risk Factors

• Stress and type A personality
• Alcohol excess
• Oral contraceptive use (especially in smokers - up to 10x risk)
• Elevated homocysteine
• High-sensitivity CRP (marker of inflammation)
• Obstructive sleep apnea
• Low socioeconomic status

• Lipoprotein(a) [Lp(a)]
• Elevated fibrinogen
• Air pollution / environmental tobacco smoke (secondhand smoke causes the same endothelial dysfunction as active smoking)

---

d) Prevention

Primordial Prevention

• Prevent risk factors from developing in the first place through community-level interventions, health education, policy changes (tobacco taxes, food labelling, restriction on trans-fats).

Primary Prevention

• Screening and controlling modifiable risk factors in healthy individuals
• Lifestyle interventions: DASH diet, Mediterranean diet, weight reduction, exercise (150 min/week moderate aerobic activity), smoking cessation
• BP control (<130/80 mmHg), statin therapy for high-risk individuals
• Low-dose aspirin (only in selected high-risk individuals per current guidelines)
• Diabetes prevention (lifestyle modification, metformin in pre-diabetes)

Secondary Prevention

• Post-MI: anti-platelets, statins, beta-blockers, ACEi/ARBs, cardiac rehabilitation
• Risk factor modification continues aggressively

Tertiary Prevention

• Cardiac rehabilitation, preventing disability and recurrences

---

Note on National Programme - NPCDCS / NP-NCD

1. Prevent and control common NCDs through behaviour and lifestyle changes
2. Provide early diagnosis and management through opportunistic screening
3. Build capacity at all levels (primary, secondary, tertiary) for prevention, diagnosis, treatment
4. Train health workforce (doctors, paramedics, nurses) to handle the NCD burden
5. Establish NCD clinics at District Hospital and CHC levels
6. Establish cancer care facilities at secondary and tertiary levels
7. Link with the National Multi-Sectoral Action Plan (NMAP) involving other Ministries (2016 onwards)

---

---

2. HYPERTENSION

---

a) Epidemiology

• Hypertension affects approximately 1.28 billion adults worldwide (WHO, 2021); only about half are aware.
• It is the leading modifiable risk factor for cardiovascular disease globally.
• Age-adjusted prevalence is highest in Africa (~27%) and lowest in the Americas (~18%).
• Only 1 in 5 adults with hypertension has it under control.

• Prevalence approximately 159 per 1000 population (NPCDCS estimates); in recent surveys (NFHS-5, 2019-21), ~21% of men and ~24% of women aged 15+ have high BP.
• Urban > rural prevalence, though rural burden is rapidly rising.
• Hypertension is a major risk factor for stroke (most common cause of stroke in India), coronary artery disease, heart failure, and CKD.

---

b) AHA Guidelines for BP Classification (ACC/AHA 2017)

---

c) Risk Factors for Hypertension

Non-Modifiable

• Age: BP tends to rise with age; systolic HTN predominates in elderly
• Family history/Genetics: Strong hereditary component (~30-60% heritability)
• Race/Ethnicity: Higher prevalence and severity in African Americans; South Asians are also at elevated risk
• Sex: Males at higher risk before age 55; after menopause, women's risk equals or exceeds men's
• Low birth weight / intrauterine growth restriction (Barker hypothesis)

Modifiable

• Excess dietary salt (sodium): >6g/day significantly raises BP; DASH diet intervention shows 8-14 mmHg reduction
• Obesity: Each 10 kg of excess weight raises SBP by 2-3 mmHg; visceral adiposity is most harmful
• Physical inactivity / sedentary lifestyle
• Excess alcohol: >2 drinks/day in men, >1 in women raises BP
• Smoking: Acute pressor effect; nicotine causes vasoconstriction; chronic endothelial injury
• Stress: Sympathetic activation, raised cortisol
• Dyslipidaemia and atherosclerosis (secondary effect on aortic stiffness)
• Diabetes mellitus: Insulin resistance promotes sodium retention, sympathetic activation
• Medications: NSAIDs, oral contraceptives, sympathomimetics, corticosteroids, decongestants
• Obstructive sleep apnea: Intermittent hypoxia, sympathetic activation
• Low potassium diet / low dietary calcium
• Chronic kidney disease (secondary hypertension)

---

d) Rule of Halves ★★★

Of ALL hypertensives in the community:
│
├─ HALF (½) are UNDIAGNOSED (unaware of their condition)
│
└─ Of those DIAGNOSED (½):
     ├─ HALF (½) are NOT on treatment (½ × ½ = ¼ of total)
     │
     └─ Of those ON TREATMENT (¼ of total):
          ├─ HALF (½) are NOT ADEQUATELY CONTROLLED (⅛ of total)
          │
          └─ Only HALF are ADEQUATELY CONTROLLED (⅛ of total = 12.5%)

• Only ~12.5% of all hypertensives in the community have their BP adequately controlled
• Highlights the enormous treatment gap in hypertension management
• Underscores the need for mass screening programs, awareness campaigns, accessible treatment, and adherence support
• Applicable to India: NFHS-5 data confirms this gap; awareness (awareness ~40%), treatment (treatment ~35%), control (~15%)

---

e) Tracking of Blood Pressure ★★

• Children and adolescents with BP in the upper percentiles for their age tend to remain in those upper percentiles as adults - their BP "tracks" upward over time
• Studies (Bogalusa Heart Study, Muscatine Study, Young Finns Study) showed that adult hypertension often has its origins in childhood
• A child with BP in the 90th-95th percentile is more likely to develop adult hypertension than a child with normal BP
• Atherosclerotic changes (fatty streaks) begin in childhood and adolescence
• Practical implication: BP measurement should begin at age 3 years routinely; earlier if risk factors are present (prematurity, low birth weight, renal disease, congenital heart disease)
• WHO and AAP recommend routine BP screening at each health visit from age 3 onwards

• Early identification of at-risk children
• Lifestyle intervention in young age (diet, exercise, weight control)
• The concept of "primordial prevention" - preventing risk factors before they develop

---

f) Prevention and Control of Hypertension

Non-Pharmacological (Lifestyle) Measures

• Dietary modification: DASH diet (rich in fruits, vegetables, low-fat dairy; reduces SBP 8-14 mmHg); restrict sodium to <5-6 g/day (reduces BP by 2-8 mmHg); increase potassium intake
• Weight reduction: Each 10 kg loss reduces SBP by 5-20 mmHg
• Regular physical exercise: 30 min of moderate aerobic activity (brisk walk, cycling) at least 5 days/week (reduces SBP 4-9 mmHg)
• Reduce alcohol: Limit to <2 units/day men, <1 unit/day women (reduces SBP 2-4 mmHg)
• Smoking cessation: No direct long-term BP reduction, but dramatically reduces overall CVD risk
• Stress management: Relaxation techniques, yoga, biofeedback

Pharmacological Measures (for Stage 1 HTN with high CV risk, Stage 2 HTN)

• First-line agents: Thiazide diuretics, ACE inhibitors, Angiotensin Receptor Blockers (ARBs), Calcium Channel Blockers (CCBs)
• Special populations: ACEi/ARBs preferred in diabetes/CKD; Beta-blockers in CAD/heart failure; CCBs in isolated systolic HTN in elderly
• Target BP: <130/80 mmHg for most adults (ACC/AHA 2017); <140/90 mmHg for older adults by some guidelines

Community/Public Health Measures

• Mass screening programs (NPCDCS/NP-NCD)
• Health education and awareness
• Salt reduction policies, food labeling regulations
• Worksite wellness programs
• School health programs (BP tracking)

---

---

3. OBESITY AND WEIGHT CONTROL MEASURES ★★★★

---

Definition

• Overweight: BMI ≥ 25 kg/m²
• Obesity: BMI ≥ 30 kg/m²
• For Asians (including Indians): WHO modified cut-offs are used:
  • Overweight: BMI ≥ 23 kg/m²
  • Obesity: BMI ≥ 27.5 kg/m²

• Men: WC > 102 cm (Western); >90 cm (Asian/Indian)
• Women: WC > 88 cm (Western); >80 cm (Asian/Indian)

• Men: WHR > 1.0 indicates central obesity
• Women: WHR > 0.85 indicates central obesity

---

Epidemiology

• Worldwide, over 1 billion people are obese (WHO 2022): 650 million adults, 340 million adolescents/children.
• In India, National Family Health Survey (NFHS-5) shows: ~24% of women and ~23% of men are overweight/obese (BMI ≥25); rapidly increasing.
• Urban areas have much higher prevalence than rural areas.
• Obesity has nearly tripled globally since 1975.

---

Consequences / Co-morbidities of Obesity

• Cardiovascular: CHD, hypertension, stroke, heart failure
• Metabolic: Type 2 diabetes, metabolic syndrome, dyslipidaemia (high TG, low HDL)
• Respiratory: Obstructive sleep apnoea, obesity hypoventilation syndrome
• Musculoskeletal: Osteoarthritis, back pain, gout
• Hepatic: Non-alcoholic fatty liver disease (NAFLD), NASH, cirrhosis
• Cancer: Breast, colon, endometrial, kidney, oesophageal cancers
• Psychosocial: Depression, anxiety, low self-esteem, social stigma
• Reproductive: PCOS, infertility, obstetric complications

---

Pathophysiology

• Pro-inflammatory cytokines: IL-6, TNF-α
• Adipokines: elevated leptin (leptin resistance), reduced adiponectin
• Elevated CRP (promotes systemic inflammation and atherosclerosis)
• Reduced lipoprotein lipase activity, promoting dyslipidaemia

---

Weight Control Measures

1. Dietary Interventions

• Energy restriction: 500-1000 kcal/day deficit to achieve 0.5-1 kg/week weight loss
• Low calorie diet (LCD): 1000-1500 kcal/day
• Very low calorie diet (VLCD): <800 kcal/day (only under medical supervision)
• Dietary composition:
  • Reduce saturated fats and trans-fats
  • Increase dietary fibre (whole grains, legumes, fruits, vegetables)
  • Reduce refined carbohydrates and added sugars
  • Adequate protein to preserve lean muscle mass
  • DASH diet, Mediterranean diet both effective
• Portion control and mindful eating

2. Physical Activity

• Recommended: At least 150-300 minutes/week of moderate-intensity aerobic activity (brisk walking, cycling, swimming)
• For weight loss: 200-300 min/week may be needed
• Resistance/strength training 2-3 days/week to preserve muscle mass
• Reduce sedentary time (sitting <8 hrs/day)
• Lifestyle activity: stairs over elevators, active commuting

3. Behaviour Modification

• Self-monitoring (food diary, activity log, wearable devices)
• Goal-setting (realistic, achievable: 5-10% body weight loss in 6 months is clinically meaningful)
• Stimulus control (removing high-calorie food from home)
• Cognitive behavioural therapy (CBT) for eating disorders/emotional eating
• Structured weight loss programs and support groups

4. Pharmacological Treatment

• Orlistat (Xenical): Lipase inhibitor; blocks ~30% fat absorption; reduces weight by 2-3 kg more than placebo
• Phentermine/Topiramate extended-release: Central appetite suppression
• Bupropion/Naltrexone: Reduces appetite and food cravings
• Liraglutide / Semaglutide (GLP-1 receptor agonists): Most effective; semaglutide 2.4 mg/week (Wegovy) reduces weight by 15-20%; also approved for obesity in India
• Tirzepatide (GLP-1/GIP dual agonist): Newest; up to 22% weight reduction in trials

5. Surgical Treatment (Bariatric Surgery)

• Roux-en-Y Gastric Bypass (RYGB): Gold standard; reduces stomach size + bypass of small intestine; 60-70% excess weight loss
• Sleeve Gastrectomy: Removes ~80% of stomach along greater curvature; 50-60% excess weight loss; most common bariatric procedure
• Laparoscopic Adjustable Gastric Banding (LAGB): Band around upper stomach; reversible
• Biliopancreatic Diversion with Duodenal Switch (BPD/DS): Most effective for super-obese; higher risk
• Benefits: Also dramatically improves T2DM, HTN, sleep apnea, dyslipidaemia

6. Community-Level Measures

• Health education in schools and workplaces
• Promoting active urban design (parks, cycling paths, walkable cities)
• Restricting marketing of junk food to children
• Nutrition labeling on packaged foods
• Taxes on sugar-sweetened beverages (e.g., India's 28% GST on sugary drinks)
• NPCDCS/NP-NCD: obesity screening and counselling at PHC/CHC levels

---

---

4. BLINDNESS

---

a) Definition of Blindness ★★★★

---

b) Categories of Visual Impairment (WHO/ICD-10)

---

c) Causes of Blindness

In India (NPCB Survey Data, 2001-2002):

Global Top Causes of Blindness (WHO 2022):

1. Cataracts - single largest cause (removable/treatable)
2. Uncorrected refractive errors - leading cause of visual impairment globally
3. Glaucoma - leading cause of irreversible blindness
4. Age-related Macular Degeneration (AMD)
5. Diabetic Retinopathy - rapidly rising due to T2DM epidemic
6. Trachoma - leading infectious cause; nearly eliminated globally
7. Onchocerciasis (River Blindness) - Africa; due to Onchocerca volvulus/Simulium flies
8. Corneal scarring (trauma, infection, vitamin A deficiency)
9. Retinopathy of Prematurity (ROP) - rising with more premature infant survival
10. Childhood blindness - Vitamin A deficiency, measles, ophthalmia neonatorum, ROP

---

d) VISION 2020: The Right to Sight ★★★★

• I - Integrated eye care into Primary Health Care systems
• S - Sustainability of national eye care programs
• E - Equity (reaching underserved, poor, rural, and marginalised populations)
• E - Evidence-based action and program planning

1. Cataract - surgical intervention (cataract surgery, IOL implantation)
2. Trachoma - SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement)
3. Onchocerciasis - Ivermectin distribution (community-directed)
4. Childhood blindness - Vitamin A supplementation, immunization, ROP screening
5. Refractive errors and low vision - spectacle provision, low vision services
6. Diabetic retinopathy - screening, laser photocoagulation, vitreoretinal surgery
7. Glaucoma - early detection, IOP management
8. Age-related macular degeneration (AMD)

• Human resource development (training ophthalmic surgeons, optometrists, ophthalmic assistants)
• Infrastructure development
• Affordable technology (provision of low-cost IOLs - pioneered in India by Aravind Eye Care System)
• Community awareness and outreach
• World Sight Day: Second Thursday of October each year (became part of IAPB in 2000)
• Over 100 WHO member states established National Prevention of Blindness Committees

• India launched the National Programme for Control of Blindness (NPCB) in 1976 - one of the earliest national programs.
• Under VISION 2020, India aimed to reduce blindness prevalence from ~1.1% to <0.3%.
• Strategies included: cataract surgery outreach, school eye screening, free spectacle distribution, trachoma control, Vitamin A supplementation (National Vitamin A Prophylaxis Programme).
• India's Aravind Eye Care System became a globally recognized model for high-volume, high-quality, affordable cataract surgery.

---

e) Preventable / Avoidable Blindness ★★★

Preventable Blindness (Prevention possible BEFORE onset):

• Vitamin A deficiency: Supplementation programs (Bitot's spots → xerophthalmia → corneal ulceration → blindness)
• Trachoma: SAFE strategy - hygiene promotion, antibiotic (azithromycin) mass distribution
• Onchocerciasis: Ivermectin community programs, vector control
• Ophthalmia neonatorum: Prophylactic 1% silver nitrate/erythromycin/tetracycline eye drops at birth
• Diabetic retinopathy: Good glycaemic control, regular fundus screening
• Glaucoma: Early detection (IOP measurement, optic disc assessment), treatment
• Retinopathy of Prematurity (ROP): Controlled oxygen therapy in NICUs, regular retinal screening of premature infants
• Trauma: Protective eye-wear in occupational settings, safe agriculture practices
• Measles: Immunisation reduces corneal scarring

Treatable Blindness (Reversal possible AFTER onset):

• Cataract: Surgical removal + intraocular lens (IOL) implantation (single most important intervention - reverses 60%+ of blindness in India)
• Refractive errors: Provision of corrective spectacles, contact lenses, or refractive surgery (LASIK)
• Corneal blindness: Corneal transplantation (keratoplasty)
• Glaucoma: Medical (timolol, latanoprost), laser, or surgical trabeculectomy (arrests progression)
• Diabetic macular oedema: Anti-VEGF injections (bevacizumab, ranibizumab), laser
• Retinal detachment: Surgical repair

• Focus on cataract surgery, school eye screening, free spectacles, training of ophthalmic personnel
• Target: achieve 0.3% or less blindness prevalence
• Now integrated under NP-NCD for comprehensive NCD management

---

---

5. DIABETES MELLITUS ★★★★

---

a) Risk Factors and Lifestyle

Non-Modifiable Risk Factors

• Age: Type 2 DM risk increases after 45 years (but now rising in younger adults)
• Family history: 1st-degree relative with T2DM doubles risk; if both parents diabetic, risk ~50-70%
• Genetics: TCF7L2, PPARG, KCNJ11 gene variants; strongly polygenic
• Ethnicity/Race: South Asians, African Americans, Hispanic Americans at significantly higher risk (South Asians develop T2DM at lower BMI)
• History of gestational diabetes mellitus (GDM): 7x increased risk of developing T2DM later
• Polycystic Ovary Syndrome (PCOS): Insulin resistance
• Low birth weight / intrauterine growth retardation

Modifiable Risk Factors / Lifestyle Factors

• Obesity and Overweight (especially central/abdominal obesity): Most important modifiable risk factor; visceral fat drives insulin resistance
• Physical inactivity: Sedentary lifestyle reduces glucose uptake in muscles
• Unhealthy diet: High refined carbohydrate intake, sugary drinks, saturated fats, low fibre diet
• Pre-diabetes (IFG or IGT): Fasting glucose 100-125 mg/dL OR 2-h OGTT 140-199 mg/dL
• Hypertension: BP ≥140/90 mmHg; linked via metabolic syndrome
• Dyslipidaemia: Triglycerides ≥250 mg/dL, HDL <35 mg/dL
• Stress (chronic psychological): Elevates cortisol, promotes insulin resistance
• Sleep disorders (obstructive sleep apnea, short sleep duration)
• Tobacco use
• Medications: Corticosteroids, antipsychotics (olanzapine, clozapine), thiazide diuretics, tacrolimus

---

b) Diagnostic Criteria for Diabetes Mellitus

WHO / ADA Diagnostic Criteria (Current):

• In the absence of symptoms, a diagnosis requires two abnormal tests (either the same test on two occasions, or two different tests)
• In the presence of classic symptoms, a single test is sufficient
• Avoid testing during acute illness (stress hyperglycaemia)

Pre-Diabetes Criteria:

Type 1 DM Additional Tests:

• C-peptide: Low/absent in T1DM; preserved in T2DM
• Anti-GAD65, Anti-IA-2, Anti-insulin, Anti-ZnT8 antibodies: Positive in autoimmune T1DM

---

c) Glycemic Index (GI)

GI = (Area under glucose curve after test food / Area under glucose curve after reference food) × 100

• More useful than GI alone as it accounts for portion size
• Low GL: <10; Medium GL: 11-19; High GL: ≥20

• Low GI diets are associated with better glycaemic control in diabetics, lower HbA1c, improved insulin sensitivity
• High GI foods cause rapid glucose spikes and rapid insulin release, promoting fat storage and hunger
• Low GI diet also protects against CHD, reduces inflammation
• Limitations of GI: influenced by food processing, cooking method, combination with other foods, ripeness of fruit
• Indian diets tend to be high GI (white rice, white bread, potatoes) - a contributing factor to India's high T2DM prevalence

---

d) Prevention and Control of Diabetes Mellitus ★★★★

Primordial Prevention

• Population-level interventions to prevent obesity, sedentary lifestyle, unhealthy diet
• Policy: sugar taxes, food labelling, active urban design

Primary Prevention

• Diabetes Prevention Program (DPP): Intensive lifestyle intervention (7% weight loss + 150 min/week exercise) reduced T2DM incidence by 58% vs placebo; metformin reduced it by 31%
• Da Qing Study (China): Diet and exercise reduced T2DM by 46% over 6 years
• Finnish Diabetes Prevention Study: 58% risk reduction with lifestyle modification

• Weight loss: 5-10% body weight reduction in overweight/obese individuals
• Physical activity: ≥150 min/week of moderate activity
• Diet modification: Low GI, high fibre, reduced saturated fat, reduced sugar-sweetened beverages
• Metformin: Recommended for pre-diabetics with BMI ≥35 or age <60 or history of GDM (ADA guidelines)
• Smoking cessation
• Breastfeeding: Protective against T2DM in both mother and child

Secondary Prevention (Early Detection and Control)

• Opportunistic screening in high-risk individuals (obese, family history, hypertension, previous GDM, PCOS, age >45)
• NPCDCS/NP-NCD India: Mandates screening for diabetes at PHC level
• Control of blood glucose: HbA1c target <7% for most adults (ADA); individualized targets (stricter or less strict based on age, comorbidities)
• HbA1c <6.5%: Target for younger patients without significant comorbidities
• Medications: Metformin (first-line), SGLT2 inhibitors (empagliflozin, dapagliflozin - benefit in CKD/CVD), GLP-1 agonists (liraglutide, semaglutide - weight loss + CV benefit), DPP-4 inhibitors, sulfonylureas, insulin
• Blood pressure control: <130/80 mmHg; ACEi/ARBs preferred
• Dyslipidaemia treatment: Statin therapy; LDL <70 mg/dL in high CV risk diabetics
• Aspirin: 75-100 mg/day for secondary CVD prevention in diabetics
• Foot care: Daily inspection, proper footwear, podiatry
• Eye examination: Annual dilated fundoscopy for diabetic retinopathy
• Nephropathy screening: Annual urine albumin-creatinine ratio, eGFR

Tertiary Prevention

• Prevent/manage complications:
  • Retinopathy: Laser photocoagulation, anti-VEGF injections, vitreoretinal surgery
  • Nephropathy: ACEi/ARBs, dialysis, transplantation
  • Neuropathy: Tight glycaemic control, gabapentin, pregabalin, duloxetine
  • CVD: Aggressive risk factor management, revascularisation
  • Foot ulcers: Wound care, debridement, antibiotics, amputation prevention
  • Diabetic education (DSME - Diabetes Self-Management Education) programs

National Programme - India

• Opportunistic blood glucose screening at all PHCs
• Free oral hypoglycaemic agents and insulin at district/CHC NCD clinics
• NCD IT portal for tracking diagnosed diabetics
• Community Health Officers (CHOs) trained at Health and Wellness Centres (HWCs) for initial screening and follow-up
• Fit India Movement and Eat Right India Campaign - promoting lifestyle changes at population level
• National Diabetes Control Programme (NDCP) - earlier programme (1987) was a precursor

---

Sources: Park's Textbook of Preventive and Social Medicine (24th ed.), Textbook of Family Medicine 9e (Elsevier), Braunwald's Heart Disease, NPCDCS/NP-NCD Government of India Guidelines, ACC/AHA 2017 Hypertension Guidelines, ADA Standards of Medical Care in Diabetes, WHO Blindness and Visual Impairment Fact Sheet, VISION 2020/IAPB, Diabetes Prevention Program Research Group.