JNC-7 definition of hypertension needs alteration

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1 JNC-7 definition of hypertension needs alteration Suresh T Yavagal, MD DM* Ravikant Patil, DM** Prabhu C Halakatti, DM*** Suresh V Patted, DM*** Sameer Ambar, DM** Basavprabhu Amarkhed, MD***** PF Kotur, MD**** ABSTRACT OBJECTIVES By altering JNC-7 definition of hypertension as per our modified definition, we tried to find out the difference in prevalence of hypertension. Our modified definition is 1 mmhg less than JNC-7 criteria. METHODS We did the analysis of data collected in Belgaum Hypertension Prevalence Study conducted by KLE University Belgaum; to know the difference between the JNC-7 classified group and modified classification what we thought can change the hypertension statistics. RESULTS According to JNC-7, only 16.3% population in our study were in normal group while 41.1% had come in pre-hypertension group and 42.6% were in hypertensive group. According to our proposed modified definition, nearly double the populations i.e. 37.4% were in normal group, 40.2% remained in pre-hypertension group and only 22.4% were in hypertension group. CONCLUSION This statistics significantly altered prevalence of hypertension from 42.6% to 22.4% indicating that by making 1 mmhg alteration in number, the prevalence could be brought down by 20.2%. This simple alteration of figure by 1 mmhg can put more than 20% of people in normal group as compared to pre-hypertensive group of JNC-7, thereby reducing the agony and psychological torture. INTRODUCTION Hypertension, is the most important public health problem worldwide till date and its impact is expected to increase over the *Professor, HOD, **Associate Professor of Cardiology, ***Professor of Cardiology, ****Registar, KLE University, *****PG Student, DM Cardiology. Correspondence: Dr. ST Yavagal, MD DM, Professor and HOD, Cardiology, Jawahar Lal Nehru Medical College, KLES Dr. Prabhakar Kore Hospital & MRC, Nehru Nagar, Belgaum , Karnataka. Ph: styavagal@yahoo.co.in next 20 years as economically developing nations improve sanitation, infant mortality and childhood immunization rates. 1 The prevalence of hypertension in adults is expected to grow from 26.4% (in 2000) to 29.2% in 2025, with most of the growth from 972 million to projected 1.56 billion affected people occurring outside of North America and Europe i.e. in the developing countries. This global epidemic of high blood pressure is expected to shift the burden of disease so that the heart disease will become the most common cause of death worldwide by the year In India, cardiovascular diseases caused 2.3 million deaths in 1990 and by 2020, and this number is projected double. Recent studies by using JNC criteria have shown that hypertension is present in 25% of urban and 10% of rural subjects in India. In addition, this percentage translates into absolute number of 42 million persons in rural and 45 million in urban areas. 3 The definition of hypertension changed dramatically over time in response to better understanding of hypertension, pathophysiology, and studies of blood pressures from the diverse communities; landmark studies of BP related health outcomes. Should the usual BP in a population be considered normal? Should the rise according to age be considered abnormal? All those and other kind of questions related to blood pressure had found answer from huge data of both clinical and epidemiological studies. Sir George Pickering clearly articulates in 1968, when he said, Arterial pressure is a quantity and its adverse effect is related numerically to it. The dividing line (between normal BP and hypertension) is nothing more than an artifact. 4 The multiple risk factor intervention trial (MRFIT), which included more than 5,50,000 male participants, confirmed a continuous and graded influence of both systolic blood pressure (SBP) and diastolic blood pressure (DBP) on coronary heart disease mortality, extending down to SBP of 120 mmhg. 5,6 Over the time various expert panels as well as JNC have changed their definition as more and more data became available. The most recent report of JNC-7, published in 2003, defines the normal BP as lower than 120/80 mmhg. Further JNC-7 states that individual with SBP from mmhg or DBP mmhg should be considered pre-hypertensive and health promoting lifestyle modifications are recommended for those person. 7 But taking in account psychology of general public, very word of hypertension, puts the person next to you in panic. Once we label the person as hypertensive or prehypertensive, it will have a serious negative impact on the social, personal, and family life of the patient. Various studies which measured quality of life (QoL) index in a patient who are labeled as hypertensive, even if adequately controlled with drugs; have shown negative impacts. Most of the studies, including report of a National Survey of General Practitioners, identified serious gap in knowledge and practice regarding diagnosis and management of hypertension. 8 Similar finding are also reported from the developed countries In our observation, most of the general physicians have a habit of writing 120/80 mmhg as normal blood pressure, and even most of them do not give much importance JICC Vol 1 Issue 1 5

2 Yavagal, et al or are ignorant about making genuine effort of beat-by-beat blood pressure measurement and error of 1 2 mmhg is present in most of reading. Even as recommended by JNC more than one reading is taken in very few cases. 12 So, if we alter the definition of JNC by just 1 mmhg, higher limit definition of pre-hypertension will include BP 121/ 81 mmhg and similarly for stage 1 or stage 2 hypertension, there could be a significant difference in the statistics of the hypertension. So, we did the analysis of data collected in Belgaum Hypertension Prevalence Study conducted by KLE University, Belgaum to know the difference between the JNC-7 classified group and modified classification, what we thought can change the hypertension statistics (Table 1). MATERIAL AND METHODS Aim of Study To find out difference in the prevalence of hypertension by altering JNC-7 definition of hypertension, as per our modified definition. Methods We decided to derive our data from KLE University Belgaum Hypertension Detection Study. In this study, it was decided to screen all persons above 30 years of Belgaum city for any hypertension. To collect correct figures it is ideal to go door to door and screen the people. But it is a difficult task. Therefore, it was decided to have around 225 centers covering the entire city of Belgaum, and people were requested to come to one of the center and get their BP checked. All staff members of Jawaharlal Nehru Medical and Dental College, staff and doctors of KLE Hospital, and Ayurvedic Colleges participated. Each center had 5 doctors. Thus, around 1100 doctors were involved in recording blood pressure and screening of public. The program was organized on Sunday, April 6, 2008 on the eve of World Health Day (April 7, 2008). Since April 7 marked the Ugadi festival, the camp was organized on April 6, All doctors of Belgaum city participated in this camp. Indian Medical Association (Belgaum), Cardiological Society of India, north-west Karnataka chapter and Indian College of Cardiology participated as co-sponsors of the project. All students of KLE University formed mobilizing teams to bring public to the screening centers. Other KLE institutions (non-medical) students worked as volunteers. All together nearly, 2000 students worked as volunteers to mobilize public. All city corporators and their party workers also participated in mobilizing work. The following data was collected, name, age, sex, previous history of hypertension, diabetes, cerebrovascular accidents, visual assessment of obesity, height, weight, abdominal girth at the level of umbilicus, etc. Blood pressure was recorded in sitting posture. Appearance of the sounds was taken as systolic pressure and disappearance of sounds was taken as diastolic pressure. When the pulse pressure was more than 60 then muffling of the sound was taken as diastolic pressure, written instructions were given in the data-collecting book. RESULTS OF THE STUDY Data operators entered all data collected into computer and with their help, data was analyzed. In total people attended the camp, (63.20%) were males and (36.80%) were females. All though the camp was organized to screen all people above 30 years yet 4106 (7.30%) were below 30 years. Only persons above 30 years i.e were taken for analysis (Tables 2, 3, 4). DISCUSSION There are multiple single center studies on prevalence of hypertension available across the country. However, there is no multicentric national prevalence data. Over the years with changing definition, a lower level of pressure (140/90 mmhg) is being used as a cut-off point to define hypertension as compared to earlier studies, which used higher levels of pressure (160/95 mmhg). This vitiates any assessment of trends of hypertension prevalence over the past few decades. Nevertheless, there appears to be a steady increase in hypertension prevalence over the last 50 years, more in urban than in rural areas. Using cut-off 160/95 mmhg for diagnosis of hypertension, studies conducted in 1950s in urban Indian populations revealed that the prevalence of hypertension ranged between 3.03% and 6.19%. Using the same criteria, the prevalence increased to 6.43% and % in Based on the revised diagnostic BP criteria of 140/90 mmhg studies from Mumbai have reported a prevalence rate of % while in Jaipur it was 36.9%. Therefore, changing definition has definitely increased prevalence of hypertension. Table 1 Criteria of blood pressure classification. JNC-7 Classification Proposed Classification Normal < 120/80 mmhg Normal < 121/81 mmhg Pre-hypertension /80 89 mmhg Pre-hypertension /81 90 mmhg Stage I hypertension /90 99 mmhg Stage I hypertension / mmhg Stage II hypertension 160/100 mmhg Stage II hypertension > 160/100 mmhg JICC Vol 1 Issue 1 6

3 JNC-7 definition of hypertension needs alteration Table 2 Age and sex distribution. Age group Male Female % % % % % % % % % % % % % % % % % % % % % 100 and above 4 0.0% 00 0% 4 0.0% % % % population screened = population screened (30 years and above) = were below 30 years hence, not included in the analysis. Table 3 Distribution of blood pressure according to JNC-7 definition. Blood pressure Male Female Normal (< 120/80 mmhg) % % % Pre-hypertensive 120/80 139/89 mmhg % % % Hypertensive 140/90 mmhg and above % % % % % % Table 4 Distribution of blood pressure (with modified definition). Age group Male Female Normal (< 121/81 mmhg) % % % Pre-hypertensive 121/81 140/90 mmhg % % % Hypertensive 141/90 mmhg and above % % % % % % According to JNC-7 only 16.3% population in our study was in normal groups while 41.2% had come in pre-hypertension group and 42.6% were in hypertensive group (Figure 1). According to our modified definition nearly double the population i.e. 37.4% was in normal group, 40.2% remained in pre-hypertension group and only 22.4% were remained in hypertension group (Figure 2). This statistics significantly altered prevalence of hypertension from 42.6% to 22.4%. That means just making 1mm alteration in number can bring down the prevalence by 20.2%, which is considering worldwide epidemic of hypertension is a very big number. Therefore, this 20.2% population, which needs drug treatment for hypertension according to JNC-7, our modified definition recommends only lifestyle modification. Even only 16.3% were normal according to JNC-7, but our modified definition converts that number to 37.4%. Therefore, JNC-7 labels this extra 21.1% population as pre-hypertensive and setting them in panicky situation. Our proposed definition by altering 1 mmhg calculation in JNC-7 definition had made the big difference to the population screened in our study. This study certainly augurs good news to the treating physicians. Next question arises immediately after considering this modified JNC-7 classification, whether ignoring 1 mmhg rise in BP translates into fatal cardiac and non-cardiac adverse effects of hypertension. Framingham Heart Study investigators developed the risk calculators for chronic heart disease (CHD). The simplest of these was adopted by the third adult treatment panel of the National Cholesterol Education Program 15 which states that cardiovascular disease risk is increased 2.5-folds in women and 1.6-folds in men with high normal BP (SBP mmhg or DBP mmhg). 16,17 Thus, the studies considered the range rather than 1 mmhg change. In both men and women, each 20 mmhg difference of SBP or approximately 10 mmhg diastolic BP was associated with more than two-folds difference in stroke death rates and with a twofolds difference in death rates from ischemic heart disease (IHD), each 10 mmhg lower SBP is associated with 33% decreased risk of stroke. 18 As all the studies, showed associated risk of hypertension when measured in range and not with 1 mmhg difference, so altering definition will not definitely change the end measurements. JICC Vol 1 Issue 1 7

4 Yavagal, et al Percentage (%) Normal (< 120/80 mmhg) Pre-hypertensive 120/80 mmhg 139/89 mmhg Hypertensive 140/90 mmhg and above Male 8.90% 25.90% 28.30% 63.20% Female 7.40% 15.20% 14.20% 36.80% 16.30% 41.20% 42.60% % Figure 1 Graph showing distribution according to JNC-definition Percentage (%) Normal (< 121/81 mmhg) Pre-hypertensive 121/81 mmhg 140/90 mmhg Hypertensive 141/90 mmhg and above Male 22.00% 26.40% 14.80% 63.20% Female 15.40% 13.80% 7.60% 36.80% 37.40% 40.20% 22.40% % Figure 2 Graph showing distribution of blood pressure according to modified definition. However, why a new definition? The public health services in developing countries particularly Asia and Africa including China, are dysfunctional. 19,20 The vast majority of the population in these countries seek care from allopathic doctors, as well as their traditional branches of medicine like Unani, Ayurveda, Homeopathy, etc. 21,22 Most of the studies from these countries reported marked deficiencies in knowledge and approach of family physicians from these countries relating diagnosis and management of high blood pressures and identified serious limitation in current practice. 23 Therefore, the measurement taken by most of the family physicians in reality is not accurate. Moreover, most of these doctors write 120/80 mmhg as a normal blood pressure, which is a very common phenomenon worldwide. That is why epidemiological studies, based on single measurement taken by the family physicians, will overestimate the prevalence of hypertension statistically. The estimated cost of hypertension and its treatment in United States alone in 2006 is 63.5 billion. Worldwide the cost is six times the above value, which involves lifestyle modification JICC Vol 1 Issue 1 8

5 JNC-7 definition of hypertension needs alteration to drug treatment. Even in United States over the last 15 years, the cost of antihypertensive drugs has increased more than 7 times the inflation rates. 24 Our modified definition will prevent the use of antihypertensive treatment in nearly half the JNC-7 population treated as hypertensive group, which can nearly bring down the cost involved by 50% to ease the already overburdened world economies. 25 So logistically speaking, if we consider the hard and ground level facts of measuring diagnosing and treating hypertension, our modified definition of JNC-7 will bring down the proposed prevalence of the hypertension in the population. This will in turn decrease the agony and psychological torture of significant number of population who have been labeled as pre-hypertensive or hypertensive. In addition, we recommend to Indian Cardiology Society as well as World Cardiology Society to initiate a comprehensive program for physician and family physicians to become aware about measurement of blood pressure in more careful and correct way. REFERENCES 1. Kearney PM, Whelton M, Reynolds K, et al. Global burden of hypertension: analysis of worldwide data. Lancet 2005;365: Ezzati M, Lopez AD, Rodgers A, et al. Selected major risk factors and global and regional burden of disease. Lancet 2002;360: Rodgers A, Lawes C, MacMahon S. Reducing the global burden of blood pressure related cardiovascular disease. J Hypertens 2000; 18(Suppl 1):S Pickering G. In: High Blood Pressure, 2nd ed. New York: Grune and Stratton, 1968: Kannel WB, Vasan RS, Levy D. Is the relation of systolic blood pressure to risk of cardiovascular disease continuous and graded, or are there critical values? Hypertension 2003;42: Neaton JD, Kuller L, Stamler J, et al. Impact of systolic and diastolic blood pressure on cardiovascular mortality. In: Hypertension: Pathophysiology, Diagnosis and Management, 2nd edn. Laragh JH, Brenner BM, eds, New York: Raven Press 1995: National High Blood Pressure Education Program Coordinating Committee. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Hypertension 2003;42: Hajjar I, Kotchen TA. Trends in prevalence, awareness, treatment, and control of hypertension in the United States: JAMA 2003;290: Krousel-Wood M, Thomas S, Muntner P, Morisky D. Medication adherence: a key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients. Curr Opin Cardiol 2004; 19: Sisson SD, Rastegar D. Physician familiarity with diagnosis and management of hypertension according to JNC-7 guideline. J Clin Hypertens 2006;8: Hyman DJ, Pavlik VN, Vallbona C. Physician role in lack of awareness and control of hypertension. J Clin Hypertens (Greenwich) 2000;2: Hagemeister J, Scheider CA, Barabas S, et al. Hypertension guidelines and their limitations: the impact of physicians compliance as evaluated by guideline awareness. J Clin Hypertens 2001;19: Jafar TH, Jafary FH, Jessani S, Chaturvedi N. Heart disease epidemic in Pakistan: women and men at equal risk. Am Heart J 2005;150: Cambell M, Grimshaw, Steen N. Sample size calculation for cluster randomized trials. J Health Serv Res Policy 2000;5: Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA 2001;285: Vasan RS, Larson MG, Leip EP, et al. Impact of high normal blood pressure on the risk of cardiovascular disease. N Engl J Med 2001; 345: Kannel WB. Blood pressure as a cardiovascular risk factor: prevention and treatment. JAMA 1996;275: Lawes CMM, Bennett DA, Feigin VL, et al. Blood pressure and stroke: an overview of published reviews. Stroke 2004;35: Liu GG, Zhao Z, Cai R, Yamada T. Equity in health care access to: assessing the urban health insurance reform in China. Soc Sci Med 2002; 55: Singh P, Yadav RJ, Pandey. A utilization of indigenous systems of medicine and homoeopathy in India. Indian J Med Res 2005;122: Jafar TH, Levey AS, Jafary FH, et al. Ethnic subgroup differences in hypertension in Pakistan. J Hypertens 2003;21: Ahmad K, Jafar TH. Prevalence and determinants of blood pressure screening in Pakistan. J Hypertens 2005;23: Jafar TH, Jessani S, Jafary FH, et al. General practitioners approach to hypertension in urban Pakistan disturbing trends in practice. Circulation 2005;111: Thom T, Haase N, Rosamond W, et al. Heart disease and stroke statistics 2006 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2006;113: Fields LE, Burt VL, Cutler JA, et al. The burden of adult hypertension in the United States : a rising tide. Hypertension 2004;44: JICC Vol 1 Issue 1 9