1. EPIDEMIOLOGY AND PREVENTION OF HYPERTENSION DR.MAHDI QADI MARCH 2005 EPIDEMIOLOGY AND PREVENTION OF HYPERTENSION DR.MAHDI QADI MARCH 2005

2. INTRODUCTION n IMPORTANCE: »MAJOR RISK FACTOR FOR STROKESTROKE CHDCHD RENAL FAILURERENAL FAILURE PERIPHERAL ARTERIAL DISEASEPERIPHERAL ARTERIAL DISEASE OTHERSOTHERS – HEART FAULURE, RETINAL ARTERY OR VEIN THROMBOSIS »COST AND BURDEN OF TREATMENT »THE BIG BENEFIT OF ITS CONTROL n WHO HYPERTENSION COMMITTIES VERY HIGH MORBIDITY AND MORTALITY 1

3. INTRODUCTION n DEFINITION : GENERAL DEFINITION DIASTOLIC > = 90 SYSTOLIC > = 140 FOR 3 TIMES (4 WEEKS BETWEEN EACH READINGS)GENERAL DEFINITION DIASTOLIC > = 90 SYSTOLIC > = 140 FOR 3 TIMES (4 WEEKS BETWEEN EACH READINGS) –IT IS ARBITRARY RISK OF MORBIDITY AND MORTALITY IS GENERALLY CONINUOUSLY CORRELATED WITH LEVEL OF BLOOD PRESSURE EVEN THE LEVEL CONSIDERD AS NORMALRISK OF MORBIDITY AND MORTALITY IS GENERALLY CONINUOUSLY CORRELATED WITH LEVEL OF BLOOD PRESSURE EVEN THE LEVEL CONSIDERD AS NORMAL EVEN SINGLE HIGH BLOOD PRESSURE STILL SHOW SOME INCREASE RISKEVEN SINGLE HIGH BLOOD PRESSURE STILL SHOW SOME INCREASE RISK DIFFERANCE WITH AGEDIFFERANCE WITH AGE 2

4. INTODUCTION –PERCENTILES & TRACKING IN CHILDREN –95% OF HYPERTENSION (HTN) IS DUE TO ESSENTIAL HTN n WHY EPIDEMIOLOGY AND RISK FACTORS OF DISEASES ARE IMPORTANT ? 3

5. CLASSIFICATION (18y & older) : n CATEGORY SYSTOLIC DIASTOLIC Normal <120 <80 Normal <120 <80 pre-Hypertention 120--139 80--89 pre-Hypertention 120--139 80--89 Hypertention Hypertention Stage 1 (mild) 140--159 90--99 Stage 1 (mild) 140--159 90--99 Stage 2 160--179 100--109 Stage 2 160--179 100--109 n The seventh report of the joint national committee on detection, evaluation and treatment of high blood pressure,usa 2003. 4

7. DESCRIPTIVE EPIDEMIOLOGY n INCIDENCE & PREVELANCE: »IN USA PREVELANCE AT CUT POINT 90 DIASTOLIC = 25.3% INCIDENCE = 3% / YEAR INCIDENCE = 3% / YEAR »IN KSA …. n HIGH RISK GROUPS: »AGE INCREASE WITH AGE »RACE MORE IN BLACKS IN SOME COUNTRIES »SES MORE IN LOW SES 5

8. ETIOLOGICAL AND RISK FACTORS - EXACT ETIOLOGY STILL CONSIDERD UNKOWN - - EXACT ETIOLOGY STILL CONSIDERD UNKOWN - –1- 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 intake 7-8 gm / day 7-8 gm / day The most important environmental factorThe most important environmental factor Retention of na   plasma volume  htnRetention of na   plasma volume  htn Noticed in cross population and clinical observationsNoticed in cross population and clinical observations 6

9. ETIOLOGICAL AND RISK FACTORS 3- Obesity » positive relation had been seen in cross sectional and longitudenal studies »bp  when obese people lose wt 4- Alcohol intake »positive relation 5- Physical inactivity 7

10. ETIOLOGICAL AND RISK FACTORS 6- Stress »Effect of acute stress in raizing the BP is well known »Effect 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 areas »Type a personality 7- Diabetes and high blood glucose level »HTN is more prevelant in diabetics & persons with IGT »Hyperinsulinemia in type 2 DM  HTN »DM  nephropathy  HTN 8

11. ETIOLOGICAL AND RISK FACTORS 8- Other dietary factors –Potassium »HTN is associated with low K intake –Animal fat & fibers »Evidences suggest that diet low in animal fats(saturated fat) & high in fibers has an antihypertensive effects –Low CA & MG »Hyper tensive effect of low intake (controversy) –Caffeine »Some put high intake as risk factor but no consistant data 9

12. ETIOLOGICAL AND RISK FACTORS 9- Environmental pollutant »The strongest evidence is regarding CADMIUM but still need further proof »LEAD is also claimed 10- Others »Persons with high normal, labile & border line BP »Childeren with persistence of relatively high BP values »NSAID »Polycythemia 10

14. PREVENTION n Low prevelance in some countries ie  HTN is potentially preventable n WHO recommend the following approaches: »Primary prevention A- Population strategy A- Population strategy B- High risk strategy »Secondary prevention n Not to forget preventive actions in children 11

15. Primary PREVENTION Primary PREVENTION * Why primary Prevention for HTN still important although secondary is effective ! A- Population strategy 1- nutrition –Low salt diet not > 5 gm / day –Moderate fat –Avoidance of excessive caloric intake –Good balance diet in general –Avoidance of alcohol 2- WT reduction 3- Exercise promotion 12

16. Primary PREVENTION 4- Behavioral changes –  Stress –Modification of personal life style –spiritual health 5- Educating the public about risk factors and motivating them for primary prevention 13

18. Primary PREVENTION B- High risk strategy 1- Detecting the high risk subjects (through good phc system &periodic medical examination) 1- Detecting the high risk subjects (through good phc system &periodic medical examination) 2- Applying the primary prevention measures on the high risk subjects 2- Applying the primary prevention measures on the high risk subjects 3- Follow up of the high risk subjects 3- Follow up of the high risk subjects 14

20. Secondary prevention A- Early case detection –HTN is a suitable disease for screening –Mass screening is expensive and need to be linked to follow up to be beneficial –Screening in the PHC services »When people come for regestration and consultation »Simple feasible and continuous »Yield is good in age 35----75 ( but advised to be done from age 18- and even earlier-) »Concentrate on high risk subjects 15

21. Secondary prevention B- Proper treatment Aim BP to be < 140 / 90Aim BP to be < 140 / 90 Importance of treating mild HTNImportance of treating mild HTN Should be comprehensive care ( ie attention to other problems & risk factors )Should be comprehensive care ( ie attention to other problems & risk factors ) Non pharmacological & pharmacologicalNon pharmacological & pharmacological Patiet compliancePatiet compliance The good yeild of proper treatment (  in complications namely stroke,heart failure and renal failure )The good yeild of proper treatment (  in complications namely stroke,heart failure and renal failure ) 16

22. ADVISED REFERENCES ADVISED REFERENCES n 1- R.Brownson. Chronic diseases epidemiology& control. n 2- Last. Public health &preventive medicine. n 3- Park. Textbook of preventive & social medicine