EPIDEMIOLOGY EPIDEMIOLOGY ANDAND PREVENTIONPREVENTION OF OF HYPERTENSIONHYPERTENSION DR.MAHDI QADI DR.MAHDI QADI MARCH 2005MARCH 2005

INTRODUCTIONINTRODUCTION

IMPORTANCE:IMPORTANCE:» MAJOR RISK FACTOR FORMAJOR RISK FACTOR FOR

• STROKESTROKE• CHDCHD• RENAL FAILURERENAL FAILURE• PERIPHERAL ARTERIAL DISEASEPERIPHERAL ARTERIAL DISEASE• OTHERSOTHERS

– HEART FAULURE HEART FAULURE ,,RETINAL ARTERY OR VEIN THROMBOSIS RETINAL ARTERY OR VEIN THROMBOSIS

» COST AND BURDEN OF TREATMENTCOST AND BURDEN OF TREATMENT» THE BIG BENEFIT OF ITS CONTROLTHE BIG BENEFIT OF ITS CONTROL

WHO HYPERTENSION COMMITTIESWHO HYPERTENSION COMMITTIES

VERY HIGH MORBIDITY

AND MORTALITY

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INTRODUCTIONINTRODUCTION

DEFINITION :DEFINITION :• GENERAL DEFINITION DIASTOLIC GENERAL DEFINITION DIASTOLIC > => = 90 90

SYSTOLIC SYSTOLIC > = > = 140140 FOR FOR 3 3 TIMES (4 WEEKS BETWEEN EACH TIMES (4 WEEKS BETWEEN EACH READINGS)READINGS)

– IT IS ARBITRARY IT IS ARBITRARY

• RISK OF RISK OF MORBIDITY AND MORTALITYMORBIDITY AND MORTALITY IS GENERALLY IS GENERALLY CONINUOUSLY CORRELATED CONINUOUSLY CORRELATED WITH LEVEL OFWITH LEVEL OF BLOOD BLOOD PRESSUREPRESSURE EVEN THE LEVEL CONSIDERD AS NORMALEVEN THE LEVEL CONSIDERD AS NORMAL

• EVEN EVEN SINGLESINGLE HIGH BLOOD PRESSURE STILL SHOW HIGH BLOOD PRESSURE STILL SHOW SOME INCREASE RISKSOME INCREASE RISK

• DIFFERANCE WITH DIFFERANCE WITH AGEAGE2

INTODUCTIONINTODUCTION

– PERCENTILESPERCENTILES & & TRACKINGTRACKING IN CHILDREN IN CHILDREN

– 95%95% OF HYPERTENSION (HTN) IS DUE TO OF HYPERTENSION (HTN) IS DUE TO ESSENTIAL HTN ESSENTIAL HTN

WHY WHY EPIDEMIOLOGYEPIDEMIOLOGY AND RISK AND RISK FACTORS OF DISEASES ARE FACTORS OF DISEASES ARE IMPORTANT ?IMPORTANT ?

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CLASSIFICATIONCLASSIFICATION (18y & older)(18y & older) ::

CATEGORY SYSTOLIC DIASTOLICCATEGORY SYSTOLIC DIASTOLIC

Normal Normal <120 <80 <120 <80

pre-Hypertention pre-Hypertention 120--139 80--89 120--139 80--89

HypertentionHypertention Stage 1 (mild)Stage 1 (mild) 140--159 90--99 140--159 90--99

Stage 2Stage 2 160--179 100--109 160--179 100--109

The seventh report of the joint national committee on detection, evaluation and The seventh report of the joint national committee on detection, evaluation and treatment of high blood pressure,usa 2003.treatment of high blood pressure,usa 2003.

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DESCRIPTIVE EPIDEMIOLOGYDESCRIPTIVE EPIDEMIOLOGY

INCIDENCE & PREVELANCE:INCIDENCE & PREVELANCE:

» IN USA PREVELANCE AT IN USA PREVELANCE AT CUT POINTCUT POINT 90 DIASTOLIC = 90 DIASTOLIC = 25.3%25.3%

INCIDENCE = 3% / YEARINCIDENCE = 3% / YEAR

» IN KSA ….IN KSA ….

HIGH RISK GROUPS:HIGH RISK GROUPS:

» AGEAGE INCREASE INCREASE WITH AGEWITH AGE» RACE RACE MORE IN MORE IN BLACKSBLACKS IN SOME COUNTRIES IN SOME COUNTRIES» SES SES MORE IN MORE IN LOW SESLOW SES

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ETIOLOGICAL AND RISK FACTORSETIOLOGICAL AND RISK FACTORS

- - EXACT ETIOLOGY STILL CONSIDERD EXACT ETIOLOGY STILL CONSIDERD UNKOWN -UNKOWN -

– 1- Genetics and family history1- Genetics and family history• .Monozygotic twins.Monozygotic twins

• 1st degree relatives1st degree relatives

• Hpt tends to run in familiesHpt tends to run in families

– 2- High salt intake2- High salt intake• 7-8 gm / day7-8 gm / day

• The most important environmental factorThe most important environmental factor

• Retention of na Retention of na plasma volume plasma volume htn htn

• Noticed in cross population and clinical observationsNoticed in cross population and clinical observations6

ETIOLOGICAL AND RISK FACTORSETIOLOGICAL AND RISK FACTORS

3- Obesity3- Obesity » positive relation had been seen in cross sectional positive relation had been seen in cross sectional

and longitudenal studiesand longitudenal studies

» bpbp when obese people lose wt when obese people lose wt

4- Alcohol intake 4- Alcohol intake » positive relationpositive relation

5- Physical inactivity 5- Physical inactivity

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ETIOLOGICAL AND RISK FACTORSETIOLOGICAL AND RISK FACTORS

6- Stress6- Stress» Effect of acute stress in raizing the BP is well knownEffect of acute stress in raizing the BP is well known

» Effect of chronic stress in causing HTN is postulatedEffect of chronic stress in causing HTN is postulated

& noticed but difficult to test it well& noticed but difficult to test it well

» HPT is more in industrial and urban areasHPT is more in industrial and urban areas

» TypeType a a personality personality

7- Diabetes and high blood glucose level7- Diabetes and high blood glucose level» HTN is more prevelant in diabetics & persons with IGTHTN is more prevelant in diabetics & persons with IGT

» Hyperinsulinemia in type 2 DMHyperinsulinemia in type 2 DMHTNHTN

» DMDM nephropathy nephropathyHTNHTN

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ETIOLOGICAL AND RISK FACTORSETIOLOGICAL AND RISK FACTORS

8- Other dietary factors8- Other dietary factors– PotassiumPotassium

» HTN is associated with low K intakeHTN is associated with low K intake

– Animal fat & fibersAnimal fat & fibers

» Evidences suggest that diet low in animal fats(saturated fat) & Evidences suggest that diet low in animal fats(saturated fat) & high in fibers has an antihypertensive effectshigh in fibers has an antihypertensive effects

– Low CA & MGLow CA & MG

» Hyper tensive effect of low intake (controversy)Hyper tensive effect of low intake (controversy)

– CaffeineCaffeine

» Some put high intake as risk factor but no consistant dataSome put high intake as risk factor but no consistant data

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ETIOLOGICAL AND RISK FACTORSETIOLOGICAL AND RISK FACTORS

9- Environmental pollutant9- Environmental pollutant» The strongest evidence is regarding CADMIUM but still need The strongest evidence is regarding CADMIUM but still need

further prooffurther proof

» LEAD is also claimedLEAD is also claimed

10- Others10- Others» Persons with high normal, labile & border line BPPersons with high normal, labile & border line BP

» Childeren with persistence of relatively high BP valuesChilderen with persistence of relatively high BP values

» NSAIDNSAID

» PolycythemiaPolycythemia

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PREVENTIONPREVENTION

Low prevelance in some countries Low prevelance in some countries ieie HTN is HTN is potentially preventablepotentially preventable

WHO recommend the following approaches:WHO recommend the following approaches:» Primary preventionPrimary prevention

A- Population strategyA- Population strategy

B- High risk strategyB- High risk strategy

» Secondary preventionSecondary prevention Not to forget preventive actions in childrenNot to forget preventive actions in children

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Primary PREVENTIONPrimary PREVENTION

* Why primary Prevention for HTN still important although * Why primary Prevention for HTN still important although secondary is effective !secondary is effective !

A- Population strategyA- Population strategy1- nutrition1- nutrition

– Low salt diet not > 5 gm / dayLow salt diet not > 5 gm / day

– Moderate fatModerate fat

– Avoidance of excessive caloric intakeAvoidance of excessive caloric intake

– Good balance diet in generalGood balance diet in general– Avoidance of alcoholAvoidance of alcohol

2- WT reduction2- WT reduction

3- Exercise promotion3- Exercise promotion12

Primary PREVENTIONPrimary PREVENTION

4- Behavioral changes4- Behavioral changes– StressStress

– Modification of personal life styleModification of personal life style

– spiritual healthspiritual health

5- 5- Educating the public about risk factors and Educating the public about risk factors and motivating them for primary preventionmotivating them for primary prevention

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Primary PREVENTIONPrimary PREVENTION

B- High risk strategyB- High risk strategy

1- 1- DetectingDetecting the high risk subjects (through good phc the high risk subjects (through good phc system &periodic medical examination) system &periodic medical examination)

2-2- Applying Applying the primary prevention measures on the high the primary prevention measures on the high risk subjectsrisk subjects

3- 3- Follow upFollow up of the high risk subjects of the high risk subjects

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SecondarySecondary preventionprevention

A- Early case detectionA- Early case detection– HTN is a HTN is a suitablesuitable disease for screening disease for screening

– Mass screening is expensive and need to be linked to Mass screening is expensive and need to be linked to follow up to be beneficialfollow up to be beneficial

– Screening in the Screening in the PHCPHC services services» When people come for regestration and consultationWhen people come for regestration and consultation

» Simple feasible and continuousSimple feasible and continuous

» Yield is good in age 35----75 ( but advised to be done from age Yield is good in age 35----75 ( but advised to be done from age 18- and even earlier-)18- and even earlier-)

» Concentrate on high risk subjectsConcentrate on high risk subjects15

SecondarySecondary preventionprevention

B- Proper treatmentB- Proper treatment

• Aim BP to be < 140 / 90Aim BP to be < 140 / 90• Importance of treating mild HTNImportance of treating mild HTN

• Should be Should be comprehensive comprehensive care ( ie attention to other problems care ( ie attention to other problems & risk factors )& risk factors )

• NonNon pharmacological pharmacological & & pharmacological pharmacological

• Patiet Patiet compliancecompliance

• The The good yeildgood yeild of proper treatment ( of proper treatment ( in complications in complications namely stroke,heart failure and renal failure )namely stroke,heart failure and renal failure )

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ADVISED REFERENCESADVISED REFERENCES

1- R.Brownson. 1- R.Brownson. Chronic diseases Chronic diseases epidemiology& control.epidemiology& control.

2- Last. Public health &preventive 2- Last. Public health &preventive medicine.medicine.

3- Park. Textbook of preventive & social 3- Park. Textbook of preventive & social medicinemedicine