Disease Control and Prevention Assignment

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Hypertension prevalence in Asia and preventive medicinetechniques

Name:- Omar SheriffFor: - Nadher GhobiSubject: - Disease Control and Prevention

1.0 Introduction

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The first studies related to Hypertension were found inn Bhagwatti (5000BC), the foods which are bitter, acid, salted and burnt give rise to painwhere students were taught in China where furthermore Confuciusproposed and propagated an dietary guideline. In Sushrit Samhita (600BC) BPhas been described Raktachapa, Thus high BPas a clinicalproblem which was known to the ancient physicians. Then in the 1913

Janeway, found high BPkill people prematurely, while Weises and Ellis in1930 conducted studies in England where he found people in mid ageshave the problem more profoundly. These studies created the pathway formore studies in the future (Sing et.al, 2000)

Global Hypertension is alarming, as per the World Health Organisation(WHO) found raised BPis estimated to cause 7.5 million deaths, about12.8% of the total of all deaths. This accounts for 57 million disabilityadjusted life years (DALYS) or 3.7% of total DALYS. Raised BPis a majorrisk factor for coronary heart disease and ischemic as well as hemorrhagicstroke. BPlevels have been shown to be positively and continuouslyrelated to the risk for stroke and coronary heart disease. In some agegroups, the risk of cardiovascular disease doubles for each increment of20/10 mmHg of blood pressure, starting as low as 115/75 mmHg. Inaddition to coronary heart diseases and stroke, complications of raisedBPinclude heart failure, peripheral vascular disease, renal impairment,retinal hemorrhage and visual impairment (WHO, 2011). High BPis definedas 140 MM Hg or greater, or an average diastolic BPof 90 mm Hg orgreater, when BPis measured twice on each of the three occasions in aperson who is not accurately ill and not taking anti Hypertensive medicine(Jekel. Et.al , 2007: Rezvi Sheriff, 2012)

Globally, the overall prevalence of raised BP in adults aged 25 and over

was around 40% in 2008. The proportion of the worlds population withhigh blood pressure, or uncontrolled hypertension, fell modestly between1980 and 2008. However, because of population growth and ageing, thenumber of people with uncontrolled hypertension rose from 600 million in1980 to nearly 1 billion in 2008 (WHO, 2011)

Initially the article will consider the types of hypertension mainly based onthe book Epidemiology, biostatistics and preventive medicine done by

Jekel et.al in 2007, then the essay will look at prevalence of hypertensionin Asia by summarising key points in the article by sing et.al 2000 on theHypertension and stroke in Asia: prevalence, control and strategies indeveloping countries for prevention. Then the essay will move itsattention methods of preventive medicine will be discussed both using

Jekkel et.al explanations as well as the article from Lindholm et.al Totalcardiovascular risk approach to improve efficiency of cardiovascularprevention in resource constrain settings. Since the course instructorrequested information on my country Sri Lanka as well to be added, it wasinitially difficult to find information as most studies corresponded to trialsor tests conducted were done in 1988, however Rezvi Sheriff who is theauthors father has provided some information he shared at presentationfor the Post Graduate Institute of Medicine (PGIM) and will be shared asrequested. Finally the Article will be concluded.

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2.0 Types of Hypertension

As per Jekel et.al show in table 1 below, as BP increases above 120 whichis at normal levels and reaches the range between 120-139 Mm Hg with adiastolic BP80-89 shows pre-hypertension and in cases such as thislifestyle changes are proposed, when BP reaches a range of 140-159 MMHg with diastolic blood pressure, then it is known as stage 1 hypertension,in this case patients are asked to take drugs mainly thiazides for mostpatients. Patients who reach 160 MM Hg and above are serious and shouldbegin diet and lifestyle changes and be treated with anti-hypertensivemedication (Jekkel et.al, 2007)

Systolic BP(MMHg)

Diastolic Bloodpressure Interpretation

Drugtreatment

=100Stage 2Hypertension Yes

Table 1: Evaluation of BPand staging of Hypertension, based on averagesystolic and diastolic blood pressures in persons who are not accurately illand are not taking antihypertensive medications (Jekkel et.al, 2007)

Hypertension is further classified as either essential hypertension, wherethe cause is unknown due to sensitivity to salt or changes rennin-angiotestin causes such while the other is non-essential hypertension aretreatable causes, such as adrenal medulla or tumours (Jekkel et.al, 2007)

3.0 Hypertension in Asia

3.1 Trends

Almost two thirds of the total world population (6 billion) live in Asia,mostly in India and China. There are rapid changes in diet and lifestyle inmost Asian countries due to economic development & social transitions inthe last 23 decades. With these changes have come the problems of diet-related chronic diseases which typically occur in middle and later adultlife, and counteract the gains in life expectancy attributable to a betterfood supply. Here are the trends in Asia as per that point:

The mortality rate for stroke had been on the decline since the mid

1960s in the developed countries of Asia, such as Australia, NewZealand, and Japan, with some improvement in Singapore, Taiwanand Hong Kong, some areas of China and Malaysia about 15 years

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India, China, Phillippines, Thailand, Sri Lanka, Iran, Pakistan, Nepal,there has been a rapid increase in stroke mortality and prevalenceof hypertension. The prevalence of hypertension according to newcriteria (.140/90 mm Hg) varies between 1535% in urban adultpopulations of Asia.

In rural populations, the prevalence is two to three times lower thanin urban subjects.

Hypertension and stroke occur at a relatively younger age in Asiansand the risk of hypertension increases at lower levels of body massindex of 2325 kg/m2. Overweight, sedentary behaviour, alcohol,higher social class, salt intake, diabetes mellitus and smoking arerisk factors for hypertension in most of the countries of Asia.

In Australia, New Zealand and Japan, lower social class is a riskfactor for hypertension and stroke.

(sing et.al 2000)

3.2 Prevalence in Asia

The prevalence of hypertension in countries of Asia was as low as 2% inrural areas to 24% in urban areas. According to new criteria of the WHO-ISH subcommittee (.140/90 mm Hg), the prevalence appears to be 535%in different countries of Asia (figure 1 and 2).

Figure 1: Population studies on prevalence of hypertention (Sing et.al2000)

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Figure 2: Comparable studies on Urban population (Sing et.al 2000)

Figure 3: comparable studies of rural populations (Sing et.al 2000)

Most Studies published from 1958 which used WHO criteria for diagnosisof hypertension have shown a steadily increasing trend in the prevalenceof hypertension (figures 1-3). Studies from the cities of Ludhiana, Bombay,

Jaipur and Moradabad showed a prevalence of more than 10%. Statisticalanalysis of this trend in comparable surveys showed a significant increasedemonstrated by non-parametric analysis (MantelHaenzel x2 +/- 6.11 P ,

alpha 0.01). The prevalence of Hypertension by WHO/ISH criteria alsoshowed a steep increase from 6.2% in 1959 to 25.6% in 1998 (figure 2).According to old WHO guidelines, the prevalence of hypertension in rural

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populations also showed an increase (Table 6). Shah in Mumbai reported aprevalence of 0.52 and +/- 0.1% and Gupta in Haryana reported aprevalence of 3.6 +/- 0.4%. However, in north India, recent studies havereported a high prevalence of 7.08 +/- 0.5% in Rajasthan and 4.3 +/- 0.4%in Uttar Pradesh.18 In south India, Kerala 67 the prevalence was as highas 17.8 +/- 1.1% in a suburban village. It seems that there is a significantincrease in the prevalence of hypertension in the last few decades in India

(MantelHaenzel x2 +/- 5.93, P , alpha 0.01). There was also a substantialincrease in mean blood pressures from the 1960s to 1998 (figure 4) (singet.al 2000) .

Figure 4: Mens blood pressure between 40-49 years (sing et.al 2000)

Since hypertension is the major cause of CAD and stroke, it is clear thatone of the biggest challenges facing public health authorities and medicalpractioners is the control of hypertension, both in individual patients andat the population level. It affects 50 million people. Americans contribute

to more (sing et.al 2000)

3.1.1 Sri Lanka

Since the instructor requested the author to conduct some studies inrelation to my home country in Sri Lanka was briefly discussed. Howeveronly few studies have been conducted in relation to this topic as the beststudy done was in 1988, therefore presentations done by the authorsfather who is Dean of the Postgraduate Institute of medicine have beentaken in to consideration. Here are some key insights from thatpresentation:

As per Sri Lanka Health Association Hypertension is classified asshown below in figure 5

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Figure 5 : SLMA guidelines (Rezvi Sheriff 2012)

90% of whose BP was normal (

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Figure 6: Mortality major risk factors in Sri Lanka (Rezvi Sheriff, 2012)

o Figure 6 depicts the major risk factors in mortality fromhypertension it was shown that high blood pressure, smoking, highcollestral were the top 3 contributors to mortality

Figure 7: forecasted increases in diabeties, hypertension and IHD (RezviSheriff 2012)

o Figure 7 shows the projected increase in Hypertension forecasted,while this has been projected based on figure 8 which shows theprevailence of Hypertension in males and females and it was foundmales had more prevailence.

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Figure 8: trends in mortality due to Cerebrovascular disease inmales/females (rezvi sheriff 2012)

3.2 The non-communicable element- nutritional and endemic factors

After reviewing descriptive epidemiological studies from many developedand developing countries, concluded that there is usually a sequence inthe emergence of chronic diseases as the diet of the developing countrybecomes more westernised (Figure 1). Overweight, central obesity andhyperinsulinemia come first, then appendicitis, diabetes and hypertensiontend to occur early, followed after several decades by coronary heartdisease, insulin resistance syndrome and gall stones, then cancer of thelarge bowel and finally various chronic disorders of the gastrointestinal

tract and bone and joint diseases and renal diseases. Such changes haveoccurred more obviously in countries or population where cultural changehas occurred (sing et.al 2000).

Furthermore he goes on to state The dietary staple in southern China,southern India and in most Asian countries has been rice for manycenturies. In north India and north China, Pakistan, Afganistan, Iran, Nepal,the main staple is wheat or corn. Traditionally fat and sugar consumptionhave been low and animal protein consumption especially low (sing et.al2000).

The salt consumption in China and Japan was 1020 g/day and in India it

varied between 520 g/day. However the diet is rapidly changing in thecities to resemble that of the more affluent countries, which has beenassociated with marked increase in overweight, hypertension, diabetesand CAD. Such trends have been reported in most of the countries of Asia.

The global availability of inexpensive vegetable fat has resulted in greatlyincreased fat consumption among low income countries such as India,China, Thailand, Philippines as well as in newly industrialised countriessuch as Taiwan, Hong Kong, Singapore, Korea etc(sing et.al 2000).

The transition has occurred at lower levels of gross national product thanpreviously and is further accelerated by rapid urbanisation and

industrialisation. In China, the proportion of upper income persons whowere consuming a relatively high fat diet (.30% en/day) rose from 22.8%to 66.6% between 1989 and 1993(sing et.al 2000).

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The lower and middle income classes also showed a rise from 19% to36.4% in the former and 19.1% to 51.0% in the latter. In India, in a recentstudy, the intake of fruits and vegetables showed no significant differencein higher and lower social classes but the consumption of visible fat wasthree-fold greater in social classes 1 and 2 than social classes 35 . Highersocial classes also have higher risk of CVD. In Japan, there is a three-foldincrease in dietary fat from 1955 when Japanese were supposed to have

undernutrition. Undernutrition was fully controlled by 1965 in Japanwithout any increase in CAD, although dietary fat intake (14.8%) wasdoubled from 1955 (sing et.al, 2000)

To prove this further as per the world Development Report of there hasbeen a marked increase salt, fat, Tobacco and sedentary behaviour hasbeen on the increase in this region (One world, 2000).

4.0 Prevention and cure of Hypertension in Asia

As per Jekell et.al 2007, Hypertension is further classified as eitheressential hypertension, where the cause is unknown due to sensitivity tosalt or changes rennin-angiotestin causes such while the other is non-essential hypertension are treatable causes, such as adrenal medulla ortumours (Jekkel et.al, 2007). Preventive medicine can take the form lifestyle modification required for mainly patients in the Pre-hypertension upto stage 2 hypertension which includes anti-hypertensive drugs plus thefollowing modifications:

1. Weight reduction2. increased physical activity3. institution of a healthy diet (increase in potassium, calcium and

magnesium)

4. reduced alcohol intake5. Reduced smoking

(Jekkel et.al 2007)

However the problem has As per Sing et.al Asia has been the education ofthe disease was poor, as per his study it was found that Awareness ofhypertension among hypertensives has not been studied in the majority ofthe studies. Only 46 (11%) of men and 44 (16%) of women hypertensivewere aware of their condition in a study by Gupta et al from Rajasthan,India. The Five City Study showed that the awareness was significantlyless at Moradabad and Nagpur compared to Calcutta (12% and 14% vs22%, P , 0.05) where it was comparable with Bombay (24%) and

Trivandrum (26%).In another study among 7630 employees in a town, theprevalence of hypertension was 33.2% of 2535 hypertensives, only 559(22.0%) were aware of their hypertension. The aware hypertensives werepredominantly symptomatic, overweight and had higher age and BP thanthe unaware hypertensives. In Pakistan 70% of the hypertensives were notaware of their hypertension (sing et.al 2000)

Hypertension in Asian countries in relatively younger populations appearsto be due to interaction of genes and environment and to nutritional

inadequacies in early age. Therefore, the dynamics of the preventioneffort may vary compared to those witnessed in the developed countries.Programmes for CVD prevention in developed countries started when theepidemic of CVD was close to its peak and the community had become

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aware and alarmed by its impact. Counselling for lifestyle modification todecrease the risk of disease is more readily accepted by such populations.However, developing Asian countries suffer from the double burden ofpretransitional and post-transitional diseases and community awarenessof the dangers of CVD is not high.The transition towards becoming anindustrial market is unleashing consumer aspirations that impatiently seekan affluent and indulgent lifestyle. There are new five star hospitals

developing in every developing country of Asia with no clinicalepidemiology department or health promotion department (sing et.al2000)

As per Jekkel et.al for type 1 and 2 hypertension in controlled via the useof drugs and anti-hypertensive medicines. He further states that medicinehas found diuretics, beta blockers, angiotensin converting enzyme (ACE)inhibitors, angiotestin blockers, calcium channel blockers, alpha blockerscan be used with the help of a suitable treatment plan can also becustomized as per the condition of the patient. In clinical trials, Thiazidedueretics and beta blockers have been shown to reducing CVD as bloodpressure, so there is an argument for starting treatment of hypertensionwith the use of Thiazide Diuretics are good for the young but bad with thesenior population. Beta blockers are good for patients with conductionabnormalities and caution has to be put forth in chronic obstructivepulmonary disease but is mainly used for patients with myocardialinfarction or angina pectoris (with no condition of abnormalities). WhileACE inhibitators were found to be useful with myocardial infarction andstroke can reduce overall mortality in high risk CVD patients (Jekkel et.al2000)

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,

figure 10: Various images for beta blockers, ACE inhibitors, Calciumblockers and Alpha blockers

It has to be remembered that most countries in Asia are resourceconstrained even in the more affluent countries such as China and India,there are severe shortages of basic medical facilities let alonesophisticated expensive equipment for prevention of CVD. Thereforeshanty et.al conducts a study where Using World Health Organization(WHO) and the International Society of Hypertension risk prediction charts,cardiovascular risk was categorized in a cross-sectional study of 8,625randomly selected people aged 40 to 80 years (mean age, 54.6 years)from defined geographic regions of Nigeria, Iran, China, Pakistan, Georgia,Nepal, Cuba, and Sri Lanka. Cost estimates for drug therapy werecalculated for three countries. She finds that a large fraction (90.0 -98.9%)of the study population has a 10-year cardiovascular risk

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figure 11: Proposed matrix chart to measure heart disease by WHO (Shanti

et.al 2011)

5.0Conclusion

The articles clearly show that Hypertension is slowly but surely increasingthe global scale and especially Asia, the changing demographics coupledwith economic and social transformation is allowing the disease to deepenin to global society. Therefore the article provides useful insights on howto administer or prevent such disease taking in to consideration theeconomic dynamic affecting society.

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6.0 References

Jekkel,FJ.Katz, Elmore, G.J and Wild M.G.D, (2007), Epidemiology,Biostatistics and preventive medicine, Saunders Elsevier, USA

WHO, 2011, Raised blood pressure,http://www.who.int/gho/ncd/risk_factors/blood_pressure_prevalence_text/en/index.html accessed 22/11/2012

Singh, R B; Suh, I L; Singh, V P; Chaithiraphan, S; Laothavorn, P; et al.,Hypertension and stroke in Asia: prevalence, control and strategies indeveloping countries for preventionJournal of Human Hypertension14. 10/11 (Oct 2000): 749-63.

Mendis, Shanthi; Lindholm, Lars H. ; Anderson, Simon G.; Alwan,Ala; Koju, Rajendra; et al, Total cardiovascular risk approach toimprove efficiency of cardiovascular prevention in resource constrainsettings, Journal of Clinical Epidemiology 64. 12 (Dec 2011):1451-1462.

One world, 2000, World Development report 2000/2001, One worldpublishing, UK

Sheriff, R., Hypertension, Power point slides, Post graduate Institute ofMedicine Sri Lanka,

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