Epidemiology prevention control of hypertension

intro to htn

1. Dr. Abhishek Tiwari, Assistant Professor, Department of Community Medicine, Moti Lal Nehru Medical College, Prayagraj Epidemiology, Prevention & Control of Hypertension

2. Learning Objectives To understand why Hypertension is a Public Health Concern To understand the Epidemiology of Hypertension What all should be done to Prevent it ? Methods available to Control Hypertension ? 11-10-2021 2

3. Introduction Hypertension or elevated blood pressure - is a serious medical condition that significantly increases the risks of heart, brain, kidney and other diseases . 11-10-2021 3

4. Introduction An estimated 1.13 billion people worldwide have HYPERTENSION, most of them (2/3rd) living in low & middle-income countries. Prevalence 30-40%, 24% in men & 20% women Prevalence > 60% in people aged >60 years In 2015, 1 in 4 men & 1 in 5 women had HTN Annual increase of 15-20% estimated by 2025 A major cause of premature death worldwide. One of the global targets for Noncommunicable diseases is to reduce the prevalence of hypertension by 25% by 2025 (baseline 2010)

5. Burden - India National Family Health Survey 2015-16 11% women and 15% in men were hypertensive Prevalence was found to be higher in males and those with high Body Mass Index. Consistent increase in prevalence with increase in BMI Now – health & wellness center are focusing on Noncommunicable Diseases and their prevention in particular

6. Hypertension B lood pressure is the force exerted by circulating blood against the walls of the body’s arteries, the major blood vessels in the body. Hypertension is when blood pressure is too high. The first ( systolic ) number represents the pressure in blood vessels when the heart contracts or beats . The second ( diastolic ) number represents the pressure in the vessels when the heart rests between beats. If on 2 different days, s ystolic BP readings on both days is ≥140 mmHg and/or the diastolic BP readings on both days is ≥90 mmHg only then we diagnose as HTN

7. Symptoms of HTN Hypertension is called a "silent killer“ Most people with HTN are unaware of their status as they have no warning signs or symptoms It is essential to get blood pressure measured regularly . When symptoms do occur, they are early morning headaches, nosebleeds, irregular heart rhythms, vision changes & buzzing in the ears Severe hypertension can cause fatigue, nausea, vomiting, confusion, anxiety, chest pain & muscle tremors. The only way to detect hypertension is to measure

8. Grading of HTN Category Systolic (mm of Hg) Diastolic (mm of Hg) Optimal <120 And < 80 Normal 120 – 129 And/or 80 - 84 High Normal 130 – 139 And/or 85 - 89 Grade 1 HTN 140 – 159 And/or 90 - 99 Grade 2 HTN 160 – 179 And/or 100 - 109 Grade 3 HTN >= 180 And/or > 110 Isolated systolic HTN >= 140 And < 9 When systolic BP & diastolic BP readings fall in different category, the higher category should be taken. Higher the BP higher the risk of Cardiovascular disease. Extent of organ damage varies in individuals with HTN, hence it depends on many factors.

9. Measurement Accurate measurement are essential under STANDARDIZED conditions for valid comparisons 3 identified source of errors Observer Error – Hearing acuity, interpretation of korotkow sounds. Instrumental error – e.g. leaking valves, cuffs not encircling arm etc. Subject errors – physical environment, position, external stimuli such as fear, anxiety & so on Sitting position is recommended and a uniform policy of measurement is essential

10. Classification Primary [Essential] Cause unknown, accounts for 90% cases, most common Secondary Some other disease process or abnormality involved in causation, like kidney disease, adrenal gland disorder, narrowing of Aorta, toxemia of pregnancy, altogether less than 10% cases

11. Risk Factors of HTN The “LIFESTYLE” disease has a range of risk factors HTN is itself a major risk factor and it has its own risk factors NON MODIFIABLE Age – BP increases with age in both sexes due to accumulation of environmental factors and ageing phenomenon Sex – in adolescence Men display higher average, difference is clearly evident in young & adults. Later on this pattern narrows & may even reverse. Post menopausal changes are contributory. .

12. Risk Factors of HTN NON MODIFIABLE Genetic factors – evidence suggests BP levels are determined partly by genetic factors, with polygenic inheritance. Twin studies - BP of monozygotic twins are strongly related than zygotic twins. In contrast no relation was found in levels of husband & wife, and between adopted children. Family studies – children of 2 normotensive parents have 3% possibility of developing HTN, while it is 45% for hypertensive parents .

13. Risk Factors of HTN NON MODIFIABLE Ethnicity – Population studies have shown higher levels in black population MODIFIABLE OBESITY – Greater the wt. gain greater the risk. On loosing weight the BP also decreases. “Central obesity” has been positively correlated with high BP SALT INTAKE – high intake 7-8 g/day increases the risk. Low sodium intake decreases the BP. Japan sodium intake is above 400 mmol /day has higher incidence .

14. Risk Factors of HTN SATURATED FAT – It raises BP & serum cholesterol. Cholesterol & LDL are involved in atherosclerosis. Recommended – greater intake of PUFA and less intake of saturated fat. Fat intake should be less than 30% of total calories. DIETARY FIBRE – beneficial in reducing total plasma total & LDL cholesterol. ALCOHOL INTAKE – high intake is harmful .

15. Risk Factors of HTN HEART RATE – hypertensive subjects were found to have higher heart rate. This may be due to resetting of sympathetic activity at a higher level PHYSICAL INACTIVITY – minimum of 30 minutes for at least 5 days a week is essential to reduce the risk of HTN and NCD. Sedentary lifestyle leads to obesity and predisposes to NCD ENVIRONMENTAL STRESS – higher noradrenaline in hypertensive supports that over activity of sympathetic system is involved .

16. Risk Factors of HTN SOCIO-ECONOMIC STATUS – earlier higher disease burden in developed countries, but now the trend is transitioning. More cases in low & middle income countries. OTHER FACTORS – most common cause of secondary HTN is oral contraception, because of oestrogen .

17. Rule of Halves Hypertension is an “ICEBERG” Disease Only 1/2 have been diagnosed Only 1/2 of those diagnosed have been treated Only 1/2 of those treated are adequately controlled Thus, only 12.5%overall are adequately controlled

18. Tracking of Blood Pressure If blood pressure of individuals were followed up over a period of years from early childhood into adult life, then those whose pressures were initially high in distribution, would continue in the same “track” as adults. This phenomenon of PERSISTENCE is called tracking & can be applied in identifying “AT RISK” children & adolescents.

19. Causes of HTN A

20. Prevention WHO recommended approach: Primary Prevention- “all measures to reduce the incidence of disease in population by reducing RISK of onset” Population Strategy High Risk Strategy Secondary Prevention We can control hypertension by medication (secondary) but the ultimate goal is PRIMARY Prevention 11-10-2021 20

21. Population Strategy- for All Even a small reduction in average BP of Population would produce large reduction in incidence of CVD complications. GOAL – to shift the BP towards lower levels with multifactorial approach & non Pharmacotherapeutic interventions 11-10-2021 21 Interventions Nutrition – DASH (dietary approach to stop HTN), low sodium & fat Weight reduction – maintain BMI < 25 Exercise promotion Behavioural changes Health Education Self Care

22. High - Risk Strategy GOAL – To prevent the attainment of levels of blood pressure which requires treatment. Appropriate for community with low prevalence of risk factors Detection of High RISK subjects by assessing all predisposing factors & clinical methods 11-10-2021 22 Interventions to identify those at Higher RISK Tracking of Blood Pressure from childhood Family History details of hypertension

23. Secondary Prevention GOAL – To detect & control high BP of effected individual Early Case detection – major problem, remember silent killer and iceberg phenomenon. SCREENING of population with adequate follow up Treatment - modern Anti-hypertensive therapy Patient compliance – “the extent to which the patients behaviour coincides with clinical prescription” . Health education improves compliance it’s a control and not cure so has to be LIFELONG 11-10-2021 23

24. Treatment India Hypertension Management Initiative (in collaboration with ICMR) Measure BP of all above 30 years If SBP >= 140 and/or DBP >= 90 mm of Hg then follow . 11-10-2021 24

25. Newer initiatives for NCD Screening at all levels in the health care delivery system from sub- centre & above Capacity building at various levels of health care for prevention, early diagnosis, treatment, rehabilitation, IEC/BCC, operational research and rehabilitation. To support for development of database of NCDs through Surveillance System and to monitor NCD morbidity and mortality and risk factors . Health promotion through behaviour change with involvement of community, civil society, community based organizations, media etc. 11-10-2021 25

26. Thank you all 11-10-2021 26