Hypertension high blood pressure Coronary heart disease heart

ﺗﻌﺮیﻒ ﺑیﻤﺎﺭیﻬﺎی ﻗﻠﺒی ﻋﺮﻭﻗی - ﺑﺮﺍﺳﺎﺱ یکی ﺍﺯ گﺰﺍﺭﺷﻬﺎی ﺳﺎﺯﻣﺎﻥ ﺑﻬﺪﺍﺷﺖ ﺟﻬﺎﻧی ﺑیﻤﺎﺭی ﻫﺎی ﻗﻠﺒی : ﻻﺕ ﺯیﺮﺍﺳﺖ ﻼ ﺷﺎﻣﻞ ﻣﺠﻤﻮﻋﻪ ﺍﺧﺘ • Hypertension (high blood pressure) • Coronary heart disease (heart attack) • Cerebrovascular disease (stroke) • Peripheral vascular disease • Heart failure • Rheumatic heart disease • Congenital heart disease • Cardiomyopathies • Deep vein thrombosis and pulmonary embolism

PARTS OF CARDIOVASCULAR EPIDEMIOLOGY 1. , Descriptive epidemiology: = Describing distribution of cardiovascular disease by means of certain characteristics such as : PERSON (i. e. , age, gender, ethnicity) TIME and PLACE 2. , Analytic epidemiology = Analyzing relationships between CVD and risk factors (which elevate the probability of a disease at population level), risk model and multicausal developments 3. , Experimental epidemiology/Interventions = Strategies of cardiovascular prevention (primordial, primary, secondary, tertiary; individual and community levels)

DESCRIPTIVE EPIDEMIOLOGY I. DISTRIBUTION PATTERNS IN THE WORLD In the world: CVD deaths account for one third of all deaths (25 -50% depending on the level of economic development) among which 50%: coronary deaths CVD made up 16. 7 million of global deaths in 2002, among which 7 million due to coronary heart disease, 6 million due to stroke Distribution of types of CVD in global deaths : Global cardiovascular deaths in 2002: 16. 7 million among which: coronary heart disease 7. 2 million > stroke 6. 0 million > 0. 9 million hypertensive heart disease > 0. 4 million inflammatory heart disease > 0. 3 million rheumatic heart disease > 1. 9 million other CVD

DESCRIPTIVE EPIDEMIOLOGY II. AGE Question: What is the relative amount of CVD in death rates in different age groups? - Early lesions of blood vessel, atherosclerotic plaques: around 20 years - adult lifestyle patterns usually start in childhood and youth (smoking, dietary habits, sporting behavior, etc. ) - Increase in CVD morbidity and mortality: in age-group of 3044 years

PROPORTION OF MORTALITY IN DIFFERENT AGE-GROUPS (MEN)

PROPORTION OF MORTALITY IN DIFFERENT AGE-GROUPS (WOMEN)

DESCRIPTIVE EPIDEMIOLOGY III. SEX Question: What is the relative amount of CVD in death rates in women and men? - Widespread idea: CVD is often thought to be a disease of middle-aged men. - Cardiovascular mortality (fatal cases) are more common among men. However, CVD affect nearly as many women as men, albeit at an older age - Women: special case (WHO, 2004) a. , Higher risk in women than men (smoking, high triglyceride levels) b. , Higher prevalence of certain risk factors in women (diabetes mellitus, depression) c. , Gender-specific risk factors (risks for women only) (oral contraceptives, polycystic ovary syndrome)

DESCRIPTIVE EPIDEMIOLOGY IV. ETHNICITY Question: What is the relative amount of CVD in death rates in different ethnic groups? - In the US: increased cardiovascular disease deaths in African -American and South-Asian populations in comparison with Whites - Increased stroke risk in African-American, some Hispanic American, Chinese, and Japanese populations - Migration: Ni-Hon-San Study: Japanese living in Japan had the lowest rates of CHD and cholesterol levels, those living in Hawaii had intermediate rates for both, those living in San Francisco had the highest rates for both

DESCRIPTIVE EPIDEMIOLOGY VI. WORLD TRENDS Developed countries: decreasing tendencies (e. g, USA: 30% between 1988 -98, Sweden: 42%) - improvement of lifestyle factors, for example, a decrease of smoking and a higher level of health consciousness in many developed countries - better diagnostic and therapeutic procedures (e. g. , bypass surgeries, hypertension screening, pharmacological treatment of hypertension and hypercholesterinaemia, access to health care) Developing countries: increasing tendencies - increasing longevity, urbanization, and western type lifestyle

ANALYTIC EPIDEMIOLOGY II. CLASSIFICATION OF RISK FACTORS

Estimated 10 -Year CHD Risk in 55 -Year-Old Adults According to Levels of Various Risk Factors Framingham Heart Study A B C D Blood Pressure (mm Hg) 120/80 140/90 Total Cholesterol (mg/d. L) 200 240 240 HDL Cholesterol (mg/d. L) 50 50 40 40 Diabetes No No Yes Cigarettes No No No Yes

Estimated 10 -Year Stroke Risk in 55 -Year-Old Adults According to Levels of Various Risk Factors Framingham Heart Study A Systolic BP* 95 -105 Diabetes No Cigarettes No Prior Atrial Fib. No Prior CVD No B C D E F 130 -148 130 -148 No Yes Yes No No No Yes Source: Stroke 1991; 22: 312 -318. *BP in millimeters of mercury (mm. Hg)

A Systolic BP* 95 -105 Diabetes No Cigarettes No Prior Atrial Fib. No Prior CVD No B C D E F 130 -148 130 -148 No Yes Yes No No No Yes *BP in millimeters of mercury (mm. Hg) Estimated 10 -year stroke risk in 55 -year-old adults according to levels of various risk factors (FHS). Source: Wolf et al. , Stroke. 1991; 22: 312 -318.

Offspring CVD Risk by Parental CVD Status: Framingham Study Parental CVD <55 men, <65 Women Risk Ratio 2. 2 1. 7 1. 0 Adjusted for: age, total/HDL Chol. ratio, SBP, smoking, diabetes, BMI

Risk of Coronary Heart Disease by Serum Cholesterol 30 -Year Follow-up, The Framingham Study Age-Adjusted Annual Rate per 1000 Serum Cholesterol Age: 35 -64* Wome Men n Age: 65 -94 Men+ Women* 84 -204 8 4 22 11 205 -234 13 5 24 15 235 -264 14 4 26 17 265 -294 15 7 23 17 295 -1124 26 10 38 32 *Trends Significant at P. 001. +P. 07.

Correlation Between Serum Cholesterol and CVD Mortality 6 -Year CVD Death Rate Per 1000 30 Multiple Risk Factor Intervention Trial (MRFIT) N=325, 346 Untreated Patients 25 55 -57 years 20 50 -54 years 15 45 -49 years 10 40 -44 years 35 -39 years 5 0 Q 1 (<182) Q 2 (182 -202) Q 3 (203 -220) Q 4 (221 -244) Q 5 (>244) Serum Cholesterol Quintile (mg/d. L) Q = serum cholesterol quintile. Kannel WB et al. Am Heart J. 1986; 112: 825 -836.

________________________________________ Lifetime Risk of CHD Increases with Serum Cholesterol ______________________________________ Cholesterol 57 44 33 34 29 19 Framingham Study: Subjects age 40 years DM Lloyd-Jones et al Arch Intern Med 2003; 1966 -1972

Age-adjusted prevalence of Adults age 20 and older with LDL cholesterol of 130 mg/d. L or higher, by race/ethnicity and sex (NHANES: 2003 -2004). Source: NCHS and NHLBI. NH – non-Hispanic.

Age-adjusted prevalence of Adults age 20 and older with HDL cholesterol <40 mg/d. L, by race/ethnicity and sex (NHANES: 2003 -2004). Source: NCHS and NHLBI. NH – non-Hispanic.

Trends in mean total serum cholesterol among adults age 20 and older, by race/ethnicity, sex and survey (NHANES : 1988 -94, 1999 -02 and 2003 -04). Source: NCHS and NHLBI. NH – non-Hispanic.

Trends in mean total blood cholesterol among adolescents ages 12 -17 by race, sex, and survey (NHES: 1966 -70; NHANES: 1971 -74 and 1988 -94). Source: NCHS and NHLBI.

Prevalence of high blood pressure in Adults by age and sex (NHANES: 1999 -2004). Source: NCHS and NHLBI.

CHD Risk by Cigarette Smoking. Filter Vs. Non-filter. Framingham Study. Men <55 Yrs. 14 -yr. Rate/1000 206 210 119 112 59

Risk Factor Sum and Obesity Framingham Study (1971 -74) and (1989 -93) Risk Factor Sum 3 2. 4 1. 8 (1971) (1989) Risk factors accumulate with weight gain 1. 2 0. 6 0 Q 1 Q 2 Q 3 Q 4 Q 5 Overall Thin Obese Risk variables include bottom quintile for HDL-C and top quintiles for cholesterol, SBP, triglycerides and glucose

Trends in prevalence of overweight among U. S. children and adolescents by age and survey (NHANES, 1971 -74, 1976 -80, 1988 -94 and 20012004). Source: Health, United States, 2006, unpublished data. NCHS.

ANALYTIC EPIDEMIOLOGY II. CLASSIFICATION OF RISK FACTORS - Systolic blood pressure >140 Hgmm and/or a diastolic blood pressure > 90 Hgmm - Free of clinical symptoms for many years (screening) - In most countries, up to 30 percent of adults suffering, increasing with age in civilized countries - Positive family history - Dietary habits (a high intake of salt, processed food, low levels of water hardness, high thyramine content of food, alcohol use) - Modern lifestyle (increased sympathetic activity, psychosocial stress, leading position in job)

ANALYTIC EPIDEMIOLOGY IV. RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE Development: Rheumatic fever usually follows an untreated beta-haemolytic streptococcal throat infection in children As a consequence, the heart valves are permanently damaged which may progress to heart failure Today mostly affects children in developing countries, linked to poverty, inadequacy of health care access Occurrence: 12 million people currently affected by rheumatic fever and RHD, two-thirds are children (5 -15 years), for example: approx. 1 000 in Sub-Saharan Africa, 700 000 in South-Central Asia, 176 000 in China, 150 000 in North Africa, 40 000 in Eastern Europe (!)

ANALYTIC EPIDEMIOLOGY V. ABNORMAL BLOOD LIPIDS - Se cholesterol: structure and functioning of blood vessels, atherosclerotic plaques - Altering functions of cholesterol fractions (LDL: risk, HDL: protection) - Estrogen: tends to raise HDL-cholesterol and lower LDLcholesterol, protection for women in reproductive age - Partially genetic determination of metabolism, partially dependent of nutrition (egg, meats, dairy products)

ANALYTIC EPIDEMIOLOGY VI. TOBACCO USE - The link between smoking and CVD (mainly CHD) was identified in 1940 - Passive smoking: additional risk - Women smokers: are at higher risk of CHD and CVD than male smokers - Several mechanisms: damages the endothelium lining, increases atherosclerotic plaques, raises LDL and lowers HDL, promotes artery spasms, raises oxigen demand of the heart muscle - Nicotine accelerates the heart rate (HR), and raises blood pressure

ANALYTIC EPIDEMIOLOGY VII. PHYSICAL INACTIVITY - Regular physical activity: protective factor - Intensity and duration (150 minutes/week intermediate or 60 minutes/week heavy) - Modernization, urbanization, mechanized transport: sedentary lifestyle (60% of global population) - Raises CVD risk and also the development of other risk factors (glucose metabolism, diabetes mellitus, blood coagulation, obesity, high blood pressure, worsening lipid profile) - Physical activity: helps reduce stress, anxiety and depression

ANALYTIC EPIDEMIOLOGY VIII. OBESITY, DIABETES MELLITUS, UNHEALTHY DIET - Body Mass Index: > 25: overweight, > 30: obesity - A modern ”epidemic”: More than 60% of adults in the US are overweight or obese, in China: 70 million overweight people - Elevates the risk of both CVD and diabetes mellitus - Diabetes mellitus: damages both peripheral and coronary blood vessels -Unhealthy diet: low fruit and vegetable, fiber content, and high saturated fat intake, refined sugar

ANALYTIC EPIDEMIOLOGY IX. PSYCHOLOGICAL AND SOCIAL FACTORS - Psychological factors (Type A behavior, hostility) - Depression and CVD: bidirectional link a. , depression may increase the risk of CVD and worsen recovery process b. , CVD may induce depression - Low socioeconomic status (SES): a. , in developed countries: less educated and lower SES groups (accumulation of risk factors) b. , in developing countries: more educated and higher SES groups (western lifestyle)

FIGURE 1 -1 CHANGING PATTERN OF MORTALITY, 1990 TO 2001. CMPN = co mm uni cable, maternal, perinatal, and nu tritional dis eas es CVD = cardio vascular dis ease INJ = injury O NC = other noncommunicabl e dis eas es. (Fr om Ma thers CD, Lopez A, Stein D, et a l: Deat hs a nd disease bu rden b y c ause: Glo bal burde n of disease est imat es for 2001 by World Ban k Count ry Groups, 200 5. Disease Con trol Pr iorities Working Paper 18 [http: // www. dcp 2. org/file/33/w p 18. pd f]. )