Lifestyle Diseases

1. Lifestyle Diseases Cardiovascular System: Hypertension High Cholesterol Diabetes Atherosclerosis Heart attack Stroke Respiratory System: COPD’s Asthma, emphysema, chronic bronchitis Lung cancer

2. Abnormalities of Blood Pressure • Hypertension • Chronic resting BP > 140/90 • Root cause of heart failure, stroke, kidney failure • weakens artery walls initiating atherosclerosis • increases afterload causing ventricular hypertrophy • positive feedback cycle involving kidney damage • Hypotension • chronic low resting BP • caused by blood loss, dehydration, anemia

3. Serum Lipoproteins • Lipids transported in blood as lipoproteins • protein and phospholipid coat around a hydrophobic cholesterol and triglyceride core • soluble in plasma; bind to cells for absorption • Categorized into 4 groups by density: more protein = higher density

4. Serum Lipoproteins • VLDL • produced by liver to transport lipids to adipose tissue for storage • when triglycerides removed, become LDLs (mostly cholesterol) • LDL • absorbed by cells in need of cholesterol for membrane repair or steroid synthesis • HDL • liver produces an empty protein shell • travels through blood, picks up cholesterol • delivers cholesterol to liver, for elimination in bile

5. Lipoprotein Processing

6. DesirableLipoprotein Levels • Total cholesterol concentration of <200mg/dL • High levels of HDL • indicate cholesterol is being removed from arteries • Low levels LDL • high LDL correlates with cholesterol deposition in arteries • Lowering blood cholesterol levels: • by only 5% with restriction of dietary cholesterol • by 15 to 20% with restriction of certain SFAs (palmitic acid) • many saturated fats are not associated with elevated LDLs • trans fats both raise LDLs & lower HDLs • omega-3 fatty acids associated with lower LDLs & higher HDLs • vigorous exercise lowers blood cholesterol

7. Insulin Resistance (IR) & Diabetes • IR: decreased sensitivity of target cells (muscle, adipose and hepatic cells) to insulin • Diabetes mellitus type 2: IR, relative insulin deficiency, and hyperglycemia • associated with obesity, hypertension, elevated cholesterol & multiple endocrine disorders • systemic dysfunction of muscle cell metabolism • chronic hyperglycemia damages blood vessels & kidney tubules, exacerbating hypertension & atherosclerosis

8. Atherosclerosis • Fatty deposits (plaques/atheromas) in arterial wall • Causes MI, aneurysm, stroke, kidney failure, etc. • Pathogenesis • Damage to arterial wall allows macrophages to enter and gather cholesterol & fat, becoming foam cells • Cholesterol can crystallize, calcification & ossification can occur • Arteries become narrowed (stenosis) • Blood clots can form at the site leading to thrombosis • Pieces of the plaque can break off forming fatty emboli • Coronary artery spasms occur • Risk Factors • Congenital • Acquired

9. Angina and Heart Attack • Angina pectoris • Partial obstruction of coronary blood flow can cause chest pain due to ischemia • Often activity dependent • Myocardial infarction • Complete obstruction causes death of cardiac cells in affected area • Referred pain • Women often experience different symptoms than men • 1/3 of MIs have no associated pain symptoms

10. Brain Circulation • Total perfusion kept constant • seconds of deprivation causes loss of consciousness • 4-5 minutes causes irreversible brain damage • flow can be shifted from one active region to another • Vessels extremely sensitive • Blood pressure, atherosclerosis, hyperglycemia Intracranial aneurysm

11. CVA (stroke) • CVA - cerebral vascular accident • brain infarction caused by ischemia • thrombosis, embolism, systemic hypoperfusion, hemmorhage • effects range from unnoticeable to fatal • blindness, paralysis, loss of sensation, loss of speech common • recovery depends on surrounding neurons, collateral circulation

12. TIA (mini-stroke) • TIA’s - transient ischemic attacks • dizziness, loss of vision, weakness, paralysis, headache or aphasia resolving within 24 hrs • often early warning of impending stroke • 10-15% chance of stroke in the next year • greatest risk in next 48 hours • ½ of that risk within next month Carotid stenosis

13. Chronic Obstructive Pulmonary Disease • Asthma • Allergen/stimulus triggers histamine release • intense bronchoconstriction (blocks air flow) • Other COPD’s usually associated with smoking • Effects •  pulmonary compliance and vital capacity • Hypoxemia, hypercapnia, respiratory acidosis • hypoxemia stimulates erythropoietin release and leads to polycythemia • cor pulmonale • hypertrophy and potential failure of right heart due to obstruction of pulmonary circulation

14. Chronic Obstructive Pulmonary Disease • Chronic bronchitis – usu associated w/smoking • also common in urban residents, and people exposed to occupational dusts (anthracosis) • also linked with alcoholism and exposure to cold and drought • ↑ residual volume & ↓ vital capacity • cilia immobilized and ↓ in number • goblet cell hyperplasia esp. in smaller airways • produces excess mucus • ideal growth media for bacteria • leads to chronic infection and bronchial inflammation

15. Chronic Obstructive Pulmonary Disease • Emphysema – usu associated w/smoking • alveolar walls break down • much less respiratory membrane for gas exchange • healthy lungs are like a sponge; in emphysema, lungs are more like a rigid balloon • lungs fibrotic and less elastic • air passages collapse • obstruct outflow of air • air trapped in lungs • shortness of breath, hyperventilation, and an expanded chest • clubbing of the fingers may be observed, a feature of longstanding hypoxia

16. Smoking and Lung Cancer • Lung cancer accounts for more deaths than any other form of cancer • most important cause is smoking • ~90% of lung cancer deaths • 69 known carcinogens • smoking rates have not decreased significantly since 1990 • in 2004, 22% of high school students were current smokers • over 8% of middle school students were current smokers

17. Lung Cancer • Squamous-cell carcinoma (most common) • begins with transformation of bronchial epithelium into stratified squamous • dividing cells invade bronchial wall, cause bleeding lesions • dense swirls of keratin replace functional respiratory tissue • Adenocarcinoma • originates in mucous glands of lamina propria • Small-cell (oat cell) carcinoma • least common, most dangerous • originates in primary bronchi, invades mediastinum, metastasizes quickly

18. Progression of Lung Cancer • 90% originate in primary bronchi • Tumor invades bronchial wall, compresses airway; may cause atelectasis (deflated alveoli) • Often first sign is coughing up blood • Metastasis is rapid; usu occurs before diagnosis • common sites: pericardium, heart, bones, liver, lymph nodes and brain • Prognosis poor after diagnosis • only 7% of patients survive 5 years

19. Healthy/Smokers Lungs - Carcinoma

20. Plastinated Lungs Smoker Normal Lung cancer