Epidemiology and regional variations in cardiovascular disease and risk factors in India

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1 Epidemiology and regional variations in cardiovascular disease and risk factors in India Rajeev Gupta, MD Department of Medicine, Fortis Escorts Hospital, JLN Marg, Jaipur, India Abstract Cardiovascular diseases (CVD) are important cause of morbidity and morbidity in India. Mortality statistics and morbidity surveys indicate substantial regional variation in CVD mortality rates and prevalence. Data from Registrar General of India has reported greater age-adjusted cardiovascular mortality in Southern and Eastern states of the country. Coronary Heart Disease (CHD) mortality is greater in South India while stroke is more in the eastern Indian states. CHD prevalence is more in urban Indian populations while stroke mortality is greater in rural regions. Case-control studies in India have identified that standard major risk factors explain more than 9% incident myocardial infarctions (MI) and stroke. INTERHEART and INTERSTROKE studies reported that hypertension, lipid abnormalities, smoking, obesity, diabetes, sedentary lifestyle, low fruits and vegetables intake and psychosocial stress are as important in India as in other populations of the world. Individual studies have reported that there are substantial regional variations in risk factors in India. At a macro-level these regional variations in risk factors explain some of the regional differences in CVD mortality. However, there is need to study prevalence of multiple CVD risk factors in different regions of India and to correlate them with variations in CVD mortality using common protocol. There is also a need to determine the causes of the causes or primordial determinants of these risk factors. Key Words Cardiovascular diseases Risk factors Epidemiology India Regional variations Introduction Cardiovascular disease (CVD) are the largest causes of mortality in the world and majority of deaths occur in low 1 and middle income economies such as India. These diseases are epidemic in urban locations and are rapidly increasing in rural subjects as well. With demographic shifts, epidemiological transition and increasing urbanization associated with increase in CVD risk factors (smoking, sedentary lifestyle, obesity, hypertension and hypercholesterolemia) and lack of policy directives aimed at chronic disease control, CVD are poised to accelerate 3 further. This review summarises the current information on CVD mortality in India with focus on Coronary Heart Disease (CHD). It evaluates studies that reported regional variations in its mortality and disease prevalence. The article also focuses on studies of risk factor prevalence, highlights the urban-rural differences and regional variations in these risk factors. Finally, we identify gaps in existing knowledge regarding epidemiology of CVD in India and suggest the way forward for research to curb the CVD epidemic currently sweeping India. Epidemiology of CVD There are no detailed reports on CVD mortality from India by the government. World Health Organization (WHO) periodically reports on proportion of deaths from CVD in India but trends are not reported due to lack of secular data. Prior to 1998, the Indian mortality data were obtained from predominantly rural populations where vital registration varied from 5-15%. Accordingly, the Registrar General of India reported that from 199 s the proportionate mortality from CVD or circulatory system diseases remained almost static at 15-1%. However, these rates were based on limited data, mainly rural, and the only significant Received: 5--11; Revised: 1--11; Accepted:--11 Disclosures: This article has not received any funding and has no vested commercial interest Acknowledgements: None J. Preventive Cardiology Vol. 1 No. 1 August 11

2 Gupta R. information on CVD mortality in urban subjects was from Maharashtra. We previously discussed the shortcomings of these reports. However, it was reported that there were significant regional variations with high CVD mortality in Goa, Tamil Nadu, Andhra Pradesh and Punjab and low mortality in Central Indian states of Uttar Pradesh, Madhya Pradesh and Rajasthan. Since 1, the Registrar General of India and Million Death Study investigators have systematically collected mortality statistics from all the Indian states using the 5 country-wide Sample Registration System (SRS) units. In the first phase of this study from 1-, causes of deaths in more than 113, subjects from 1.1 million homes were analysed using a validated verbal autopsy 5 instrument. CVD was the largest cause of deaths in males (.3%) as well as females (1.9%) and led to about two million deaths annually. The Global Status on Non- 1 Communicable Diseases Report (11) has reported that > <1 No data Figure 1 Cardiovascular mortality in different countries there were more than.5 million deaths from CVD in India in 8, two-thirds due to CHD and a third to stroke. These estimates are greater than reported by the Registrar General of India and shows that CVD mortality is increasing rapidly in the country. There are country-level differences in cardiovascular mortality in the world (Figure 1). The report on CVD in low income countries by the American Institute of Medicine shows that there are substantial country-level variations. The highest age-adjusted mortality is observed in countries of Central Asia, East and Central Europe, some countries in Africa and the lowest rates are observed in West European and North American countries. There are within country variations also and the report presents significant differences in regions and locations within country in many large nations such as USA, Russia and China. In India, CVDs are the largest causes of mortality in all regions of the country. Table 1 shows top five causes of deaths in different populations (rural vs. urban, economically backward vs. developed states, men vs. women, and at all-ages vs. middle aged individuals). CVD is the largest cause of mortality in each of these groups. There are large regional differences in cardiovascular mortality in India among both men and women (Figure ). The mortality is the highest in South Indian states, Eastern and North-eastern states and Punjab in both men and women while mortality is the lowest in Central Indian states of Rajasthan, Uttar Pradesh and Bihar. Sub-analysis of the mortality trends shows that CHD mortality is higher in the South Indian states while stroke mortality more in the Eastern Indian states. There is no currently available information on trends in CVD mortality in India or different regions and states. The ongoing prospective phase of the Million Deaths Study from -13 shall provide Table 1: Top Five Causes of Deaths in India - Classified According to Areas of Residence and Gender Rank India (all age groups) Economically backward states Economically advanced states Rural populations Urban populations Men Women Middle-age (5-9 years) 1 Cardiovascular Cardiovascular Cardiovascular Cardiovascular Cardiovascular Cardiovascular Cardiovascular Cardiovascular COPD, asthma Diarrhoeas COPD, asthma COPD, asthma Cancers COPD, asthma Diarrhoeas COPD, asthma 3 Diarrhoeas Respiratory Cancers Diarrhoeas COPD, asthma Tuberculosis COPD, asthma Tuberculosis infections Perinatal COPD, asthma Senility Perinatal Tuberculosis Diarrhoeas Respiratory infections Cancers 5 Respiratory infections Perinatal Diarrhoeas Respiratory infections Senility Perinatal Senility Ill-defined (Adapted from Registrar General of India report, 9) 8 J. Preventive Cardiology Vol. 1 No. 1 August 11

3 Epidemiology of CVD in India Males Females properly designed prospective studies to correctly identify trends. Regional variations in burden of CVD using a uniform protocol have not been studied and there is need to conduct such studies. CVD risk factors robust data on trends in CVD mortality in India. Morbidity CVD death rate per 1, < > 35 Figure Regional variations in cardiovascular mortality in different states of India in men and women according to Million Death Study (1-3) WHO has predicted that from years to disability adjusted life years lost (DALYs) from CHD in India shall double in both men and women from the current. and 5.5 million respectively. It has also been estimated that larger DALYs shall be lost by cerebrovascular diseases as compared to CHD in India. These data do not report on regional variations within a large country such as India and more region-specific data are needed. In the last 5 years, there have been multiple cardiovascular epidemiological studies in India that have defined prevalence of CHD and stroke and identified burden of disease. Prevalence studies have diagnosed CHD using history and ECG changes (Q-wave, ST-T changes). A meta-analysis of these studies reported that prevalence rates have more than quadrupled in both urban 8 and rural populations. The increase in CHD and stroke in India is largely an urban phenomenon and only recently a rapid rise in rural populations has been reported. Studies in middle of last century reported a low prevalence of 1-% in urban locations and.5-1% in rural locations with very little urban-rural difference. In the intervening years, the CHD prevalence in urban areas increased to1-1% while it increased to only -5% in rural adults. Stroke prevalence studies report a substantial burden of stroke in urban and rural subjects. Stroke is also increasing in India and incidence registries using population-based surveillance have reported that annual incidence of stroke varies from 1-15/1, population in urban locations with 9 greater incidence in rural regions. However, these studies provide only limited information and there is need for J. Preventive Cardiology Vol. 1 No. 1 August 11 There are no prospective cardiovascular epidemiological studies that have identified risk factors of importance in India. Multiple case-control studies exist. The largest of these case-control studies is the INTERHEART performed 1 on more than a thousand cases and controls. This study reported that standard risk factors such as smoking, abnormal lipids, hypertension, diabetes, high waist-hip ratio, sedentary lifestyle, psychosocial stress, and lack of consumption of fruits and vegetables explained more than 9% of acute CHD events in South Asians. Similar conclusions were reached in smaller case-control studies. 11 The INTERSTROKE study reported that ten common risk factors explained more than 9% incident haemorrhagic and thrombotic strokes. The risk factors are similar to the INTERHEART study but the population attributable risks are different with greater importance of hypertension and lesser importance of diabetes and lipids (Table ). Table : Population Attributable Risks (%) of various CVD Risk Factors for CHD and Stroke in INTERHEART and INTERSTROKE studies Risk Factor INTERHEART INTERSTROKE (acute myocardial (thrombotic or infarction) haemorrhagic strokes) Apolipoprotein 9..9 A/B ratio Hypertension 1.9 (history) 3. Smoking Diabetes history High Waist-hip ratio.1.5 Psychosocial stress Regular physical activity Diet/diet score Lack of alcohol intake. 3.8 Cardiac causes -. Reviews of epidemiological studies suggest that all the major cardiovascular risk factors are increasing in India (Figure 3). Tobacco production and consumption has increased significantly. Smoking is increasing among 9

4 Gupta R. young subjects (-35 years) according to second and third National Family Health Surveys (NFHS). Among urban populations smoking is increasing among the low 1 educational status subjects. Prevalence of hypertension has increased in both urban and rural subjects and presently 13 is 5-% in urban and 1-15% among rural adults. Lipids levels are increasing and serial studies from a North Indian city reported increasing mean levels of total, LDL and non-hdl cholesterol and triglycerides and decreasing 1 HDL cholesterol. Although there are large regional variations in prevalence of diabetes it has more than quadrupled in the last years from <1-3% to 1-15% in 15 urban and 3-5% in rural areas. Studies have reported increasing obesity as well as truncal obesity, due to sedentary lifestyles and psychosocial stress in the country. 1 1 Figure 3 Secular trends in prevalence of major coronary risk factors in India. Smoking, hypertension, hypercholesterolemia and diabetes show a significant increase both in urban (square markers) and rural (triangular markers) populations Regional variations In India, there has been no national study that used uniform methodologies to assess regional variations in multiple cardiovascular risk factor prevalence. A study in 19 s by 1 Chopra et al assessed difference on mean BP levels among army recruits belonging to different states in India and reported higher mean levels in north Indian states as 1 compared to the south. Malhotra performed a study among railway employees in 19 s studied variations in dietary habits and cardiovascular mortality in different regions of India. Greater CVD mortality was observed among north Indian railway men which were related to greater consumption of calories and fats. The multisite 18 Prevalence of Diabetes in India Study (PODIS) focussed on epidemiology of diabetes prevalence in the country and performed studies in all the large Indian states but did not report the regional variations. The multi-city Diabetes Smoking/tobacco use Smoked per adult Tobacco production I I Hypertension > 1/9 Men Women R =.3 R = I Type diabetes R = R = Hypertension > 1/95 R = Cholesterol mean mg/dl R = R = Epidemiology Study in India (DESI) reported on differences in prevalence of diabetes in eight urban 19 locations. Greater prevalence of diabetes was reported in south India as compared to other regions. NFHS-3 inquired for prevalence of self-reported diabetes and reported a low prevalence of this condition in this countrywide study precluded further analyses for determination of regional differences. A few studies evaluated prevalence of multiple CVD risk factors in two-three cities of India using uniform methodology. An Indian Council of Medical Research (ICMR) study in 199s evaluated risk factors in Delhi (North) and Vellore (South) and reported significantly greater prevalence of risk factors in the northern part of 1 India. A multisite Indian Industrial Population Surveillance Study (8 sites) reported variable prevalence of risk factors among industrial workers. An ICMR surveillance study also evaluated differences in selfreported prevalence of CVD risk factors in different Indian 3 states in rural and urban populations. No consistent regional differences were observed. A multisite study involving five rural and four urban sites in middle-aged women reported prevalence of CVD risk factors in different regions of India. The results focussed on assessment of urban-rural differences and not on regional variations. An analysis of reviews of CVD risk factor epidemiological studies shows significant regional variations in prevalence of important CVD risk factors- smoking, obesity, hypertension, diabetes and lipid abnormalities. The second and third NFHS reported prevalence of smoking and tobacco use in populations of all Indian states. There were significant state-level and regional variations in, smoking. The smoking rates were the highest in Eastern Indian states and the lowest in Punjab. The second and third NFHS also reported on differences in prevalence of overweight and obesity among men and women in different Indian states. Prevalence of overweight and obesity was the highest in southern and northern Indian states and the lowest in Central Indian states (Figure ). Regional variations in other cardiovascular risk factors are not well reported within a single study using uniform methodology. Review of hypertension epidemiological studies report that prevalence of hypertension is significantly in urban populations in India as compared to 13 the rural. However; no consistent trends were observed for regional variations. In rural populations, the prevalence of hypertension is higher in Rajasthan while in urban J. Preventive Cardiology Vol. 1 No. 1 August 11 5

5 Epidemiology of CVD in India Urban-rural differences CVD diseases are epidemic in urban regions of low income countries such as India. Cardiovascular mortality data from India has reported large regional variations with annual mortality rates greater than 5/1, in southern and eastern regions of the country and less than 1/1, in central India (Figure ). Figure Prevalence of overweight in different states of India in second ( ) and third (5-) National Family Health Surveys (NFHS) in India 13 studies prevalence rates are similar. Prevalence of hypertension was the highest in metropolitan cities such as Mumbai and low in less populated cities (Table 3). An important finding is that hypertension prevalence in rural populations are approaching the rates in urban subjects. There are large urban-rural differences in cardiovascular mortality also with rates of less than /1, in rural areas and 5-5/1, in metropolitan urban locations (Figure 5). Only a few prospective studies of cardiovascular mortality are available in India. A small 8 study in rural Gujarat and a larger study in rural Andhra 9 Pradesh reported annual mortality rates of - 3 5/1, while studies in urbanised Kerala and 31 Mumbai have reported a very high cardiovascular mortality with rates approaching 5/1, for men and 5/1, for women. These rates are almost twice that of USA (Figure 5). Causes for these urban-rural differences in CVD mortality Table 3: Recent Studies of Hypertension Prevalence in India First Author Year Reported Place Age group Sample size Prevalence Urban Populations Gupta R 1995 Jaipur > Anand MP Mumbai Gupta R Jaipur > Shanthirani CS 3 Chennai > Gupta PC Mumbai > Prabhakaran D 5 Delhi Reddy KS National Mohan V Chennai > 35. Kaur P Chennai Yadav S 8 Lucknow > Rural Populations Gupta R 199 Rajasthan > Kusuma Y Andhra > Hazarika NC Assam > Krishnan A 8 Haryana Todkar SS 9 Maharashtra > 19. Bhardwaj R 1 Himachal > Yuvraj BY 1 Karnataka > Kinra S 1 National J. Preventive Cardiology Vol. 1 No. 1 August 11 11

6 Gupta R. Rates/1, Gujarat 198 n=5 Rural India 55 5 Andhra n=181 Men 9 Women Urban India 31 kerala1 n= Mumbai 1 n= USA 5 have not been systematically evaluated but previous studies from India have reported that there are significant urban-rural differences in metabolic cardiovascular risk factors. Prevalence of smoking is greater in rural men while all other risk factors such as sedentary lifestyle, obesity, central obesity, hypercholesterolemia, diabetes and the metabolic syndrome are more in urban men and 3 women. A recent nationwide study among women has reported greater prevalence of multiple CVD risk factors in urban women (Table ). This is similar to the previous studies on urban-rural differences in cardiovascular risk factors using uniform protocols reported from Haryana, Delhi, Rajasthan and Tamilnadu. Figure 5 Urban-rural and regional variations in cardiovascular mortality in India in recent population-based prospective studies Greater prevalence of cardiovascular risk factors in urban areas in India is in contrast to high income countries where 33 the CVD risk factors are equal in urban and rural areas. Table : Greater Prevalence of CVD Risk Factors in Indian Women in a Nationwide Study Variable Urban (n=8) Rural (n=1) Urban-rural relative risk (95% CI) Smoking/tobacco use (n=393) Current users 3 (19.) 81 (1.).35 (.18-.5) Smoking 1 (.) (1.).9 (.1-.) Non-smoked tobacco use 35 (1.) (3.). ( ) Former users (stopped > months) 1 9 (1.) (.1).9 (.-5.55) Sedentary lifestyle (n=) 1 (1.) 1558 (.1) 1.3 (.9-.9) Physical activity levels <1.55 units Overweight/obesity (n=1) BMI kg/m 355 (11.) 3 (1.5).91 (.-.11) BMI kg/m (31.) 51 (1.8).3 (1.1-3.) BMI 3. kg/m 88 (13.9) 15 (5.).55 ( ) Truncal obesity (n=11) WHR >.9 88 (.3) 318 (13.3) 5. (.1-1.3) Waist circumference >9 cm 38 (31.) (8.) 5.1 (.-11.9) Hypertension 95 (8.) (31.) 1.9 ( ) Hypercholesterolemia (n=35) mg/dl 188 (5.) 15 (5.1) 1.8 (.-1.89) mg/dl 55 (.) 3 (13.5).39 ( ) Impaired fasting glycemia (n=38) <1 gm/dl 118 (.) 138 (8.9).3 (.15-.) 1-15 gm/dl (.3) 3 (1.1).5 ( ) Diabetes (FPG 1 gm/dl or history) (n=8) 9 (15.1) 98 (.3). ( ) 1 J. Preventive Cardiology Vol. 1 No. 1 August 11

7 Epidemiology of CVD in India This is due to advancing disease and epidemiological transition and it is likely that prevalence of risk factors would change in India with socioeconomic development of rural areas. There is recent evidence that in more developed states of India such as Kerala, the rural-urban differences in cardiometabolic risk factors have largely disappeared and the risk factors are equal or slightly greater in rural 3 subjects. Whether similar situation emerges in other Indian states is matter of future studies. Recent studies in certain states have reported high prevalence of diabetes (Figure 3) and hypertension (Table 3) in some rural locations in South and West India. Trends in risk factors An important focus of recent studies is changing trends in cardiovascular risk factors. Reappraisal of various reviews articlessuggests that all major risk factors are increasing in 35 India (Figure 3). In the last 3 years, prevalence of hypertension and hypercholesterolemia has doubled while that of diabetes has trebled. However, there are almost no studies that have evaluated risk factors using either a prospective cohort design or multiple cross-sectional designs. Such studies are urgently required. The Global Burden of Diseases Chronic Disease Risk Factors Collaborating Group has reported that 35-year trends (198-5) in mean levels of BMI, systolic BP and cholesterol are different in high income countries, middle income countries and low income countries (such as 3 India). This study evaluated trends in these risk factors using data from local and regional population-based epidemiological studies. Increasing trends in BMI were observed in all the three regions with greatest increase in high income countries and lesser magnitude of increase in low income countries. Mean systolic BP declined in high and middle income countries but increased in low income countries and is now more than in high income countries. Mean cholesterol levels have also declined in high and middle income countries but have increased in low income countries. The India specific data were similar to the overall trends in low-income countries. Gaps in knowledge There are significant gaps in knowledge of epidemiology of CVD and their risk factors in countries of South Asian region such as India. The mortality data have been inadequately collected and collated and there is little information on regional variations in CVD incidence and mortality. Secondly, there are no national studies that have evaluated the disease incidence and prevalence. Studies in 3 similar densely populated regions in Europe, North America and China have reported significant regional variations in CVD mortality, CVD prevalence and incidence and major cardiovascular risk factors. Thirdly, the reasons for regional variations of CVD in India are not well studied. For example, CVD mortality is greater in 3 North European countries than in South Europe. This is associated with greater prevalence of hypertension, hypercholesterolemia and diabetes in North Europe. CVD mortality is more in Northern region of England related to multiple socioeconomic factors as well as greater smoking, obesity and lipid abnormalities. CVD mortality, 38 especially stroke, is more in south-west of USA associated with greater prevalence of abnormal lifestyles, obesity and hypertension. In China cardiovascular diseases, especially stroke mortality is greater in the North- 39 east and this is due to greater prevalence of obesity and hypertension. Fourthly, regional variations in CVD risk factors such as smoking, obesity, hypertension, diabetes and lipid abnormalities have not been systematically studied. The government of India sponsored National Sample Survey Organization (NSSO) surveys and NFHS have been going on since last many years but have not focused on noncommunicable diseases such as CVD. Only in the recent NFHS- and NFHS-3 has there been an attempt to quantify,5 smoking and tobacco use and adult body weight. Other risk factors have not been studied. There have been a number of ad-hoc population-based surveys for estimation of CVD risk factor prevalence in India as reported above. All these studies have been performed by local investigators using different age-groups, variable sample sizes, non-uniform methodology, improper statistical techniques and reported results inconsistently. Fifthly, there are no prospective studies in India that have evaluated either the incidence of CVD or risk factor associations. The Prospective Urban Rural Epidemiological (PURE) study is he only large study for prospective identification of risk 1 factor disease association. And finally, due to lack of national data there are no national efforts to initiate policy change for controlling the cardiovascular disease 3 epidemic. There are no clinical initiatives to change the population-wide distribution of risk factors or to evaluate the efficacy of high-risk approach for risk factor control and disease management. Clearly, there is need to perform multisite and multicity studies for identification of cardiovascular risk factor prevalence in high income countries using uniform methodology. Such studies have been reported from Europe and North America. The US National Health and Nutrition Evaluation Surveys have periodically assessed risk factor studies in the country and have reported greater J. Preventive Cardiology Vol. 1 No. 1 August 11 13

8 Gupta R. prevalence of hypertension and metabolic risk factors in the South-eastern states. The British Regional Heart 3 Study and similar studies in Europe have reported almost similar prevalence of risk factors in different regions of these countries. Studies in Europe have reported greater prevalence of cardio metabolic risk factors in the North and East European countries as 3 compared to the southern countries. The CARMELA study in seven Latin American cities in Argentina, Chile, Colombia, Ecuador, Mexico, Peru and Venezuela reported high prevalence of smoking, hypertension, hypercholesterolemia and diabetes in these cities. The study reported a high prevalence of all these risk factors in urban communities in these countries with different 39 socioeconomic levels. Regional studies in China have reported greater hypertension and hypercholesterolemia prevalence in the south-western regions as compared to others. In conclusion, this review shows that there are wide regional variations in cardiovascular mortality in India. Apart from the well known gender based differences, there are variations in mortality in different states and in urban and rural regions and among different socioeconomic groups within states. Although no nationwide study of risk factors exists, review suggests that there are significant state-level and rural-urban differences in major CVD risk factors. However, there is need to perform nationwide studies for determining these risk factors using uniform protocols to assess regional differences. There is also a need to determine the causes of the causes or primordial determinants of these risk factors. References 1. World Health Organization. Global Status Report of NCD 1. Geneva. World Health Organization Fuster V, Kelly BB, and Board for Global Health. Promoting cardiovascular health in developing world: a critical challenge to achieve global health. Washington. Institute of Medicine Gupta R, Guptha S, Joshi R, et al. Translating evidence into policy for cardiovascular disease control in India. Health Res Policy Syst. 11; 9:8.. Gupta R, Misra A, Pais P, et al. Correlation of regional cardiovascular disease mortality in India with lifestyle and nutritional factors. Int J Cardiol. ; 18: Registrar General of India. Report on causes of deaths in India 1-3. New Delhi. Registrar General of India, Ministry of Home Affairs. 9.. Mony P. Geographic epidemiology of cardiovascular disease in India: an exploratory study. MSc Thesis, University of Toronto, Canada. Available at: Last th accessed on August, 11.. Gupta R, Joshi PP, Mohan V, et al. Epidemiology and causation of coronary heart disease and stroke in India. Heart. 8; 9: Gupta R, Gupta VP. Meta-analysis of coronary heart disease prevalence in India. Indian Heart J. 199; 8: Sridharan SE, Unnikrishnan JP, Sukumaran S, et al. Incidence, 1 types, risk factors and outcome of stroke in developing country: the Trivandrum Stroke Registry. Stroke. 9; : Joshi P, Islam S, Pais P, et al. Risk factors for early myocardial infarction in South Asians compared with individuals in other countries. JAMA ; 9: O Donnell M, Xavier D, Liu L, et al. on behalf of the INTERSTROKE Investigators. Risk factors for ischemic and intracerebral haemorrhagic stroke in countries (the INTERSTROKE study): a case-control study. Lancet 1; 3: Gupta R, Gupta VP, Sarna M, et al. Serial epidemiological surveys in an urban Indian population demonstrate increasing coronary risk factor among the lower socioeconomic strata. J Assoc Physicians India. 3; 55:-. 13.Gupta R. Trends in hypertension epidemiology in India. J Human Hypertens ; 18: Gupta R, Guptha S, Agrawal A, et al. Secular trends in cholesterol lipoproteins and triglycerides and prevalence of dyslipidemias in an urban Indian population. Lipids Health Dis. 8; : (e1- e13). 15.Anjana RM, Ali MK, Pradeepa R, et al. The need for obtaining accurate nationwide estimates of diabetes prevalence in India: rationale for a national study on diabetes. Indian J Med Res 11; 133: Chopra RN, Chopra GS. A study of normal blood pressure in Indians. Ind Med Gazette. 19; :1-. 1.Malhotra SL. Studies in blood coagulation, diet, and ischemic heart disease in two population groups in India. Br Heart J 198; 3: Sadikot S, Nigam A, Das S, et al. Diabetes India. The burden of diabetes and impaired glucose tolerance in India using the WHO 1999 criteria: the prevalence of diabetes in Indian study (PODIS). Diab Res Clin Pract ; : Ramachandran A, Snehalatha C, Kapur A, et al. High prevalence of diabetes and impaired glucose tolerance in India. Diabetologia 1; : Indian Institute of Population Sciences and Macro International. National Family Health Survey 5- (NFHS-3). Mumbai. Indian Institute of Population Sciences.. 1.Reddy KS, Prabhakaran D, Shah P, et al. Differences in body mass index and waist:hip ratios in North Indian rural and urban populations. Obesity Rev ; 3:19-..Reddy KS, Prabhakaran D, Chaturvedi V, et al. on behalf of the Sentinel Surveillance System for Indian Industrial Populations Study Group. Methods for establishing a surveillance system for cardiovascular diseases in Indian industrial populations. Bull WHO. ; 8: Mohan V, Mathur P, Deepa R, et al. Urban rural differences in prevalence of self-reported diabetes in India: WHO-ICMR Indian NCD risk factor surveillance. Diab Res Clin Pract. 8; 8: Pandey RM, Gupta R, Gupta R, et al. Determinants of urban-rural differences in cardiovascular risk factors in middle-aged women in India: A cross-sectional study. Int J Cardiol. 11 : doi. 1.11/j.ijcard Subramanian SV, Nandy S, Kelly M, et al. Patterns and distribution of tobacco consumption in India: cross sectional multilevel evidence from the national family health survey. BMJ ; 38: Wang Y, Chen HJ, Shaikh S, et al. Is obesity becoming a public health problem in India? Examining the shift from under- to overnutrition problems over time. Obesity Rev 9; 1:5-..Deedwania PC, Gupta R. Hypertension in South Asians. In: Black HR, Elliott WJ. Editors. Hypertension: A Companion Textbook to Braunwald s Heart Disease. nd Edition. New York. WB Saunders. 11; In press. 8.Trivedi DH, Sharma V, Pandya H, et al. Longitudinal epidemiological study of coronary heart disease in a rural population of Kheda district, Gujarat, India. Soz Preventivmed J. Preventive Cardiology Vol. 1 No. 1 August 11

9 Epidemiology of CVD in India 199; 1: Joshi R, Cardona M, Iyengar S, et al. Chronic diseases now a leading cause of death in rural India: mortality data from the Andhra Pradesh Rural Health Initiative. Int J Epidemiol. ; 35: Soman CR, Kutty VR, Safraj S, et al. All-cause mortality and cardiovascular mortality in Kerala state of India: Results from a 5- year follow-up of 119 rural community dwelling adult. Asia Pac J Pub Health 1; Epub: May 1, Pednekar MS, Gupta R, Gupta PC. Illiteracy, low educational status, and cardiovascular mortality in India. BMC Public Health. 11; 11:5. 3.Gupta R, Gupta VP. Urban-rural differences in coronary risk factors do not fully explain greater urban coronary heart disease prevalence. J Assoc Physicians India. 199; 5: Stuckler D. Population causes and consequences of leading chronic diseases: a comparative analysis of prevailing explanations. Milbank Q. 8; 8: Thankappan KR, Shah B, Mathur P, et al. Risk factor profile for chronic non-communicable diseases: results of a community based study in Kerala, India. Indian J Med Res. 1; 131: Gupta R. Coronary heart disease in India: From epidemiology to action. Fortis Medical J. 9; (1): Anand SS, Yusuf S. Stemming the global tsunami of cardiovascular disease. Lancet. 11; 3: Mariotti S, Copocaccia R, Farchi G, et al. Age, period, cohort and geographic area effects on the relationship between risk factors and coronary heart disease mortality. 15-year follow-up of the European cohorts of the Seven Countries study. J Chronic Dis. 198; 39: Centre for Disease Control and Prevention. Estimated prevalence of diabetes and obesity in United States. MMWR. 9; 58: Liu M, We B, Wang WZ, et al. Stroke in China: epidemiology, prevention, and management strategies. Lancet Neurology ; :5-..Heart disease mortality. Available at: Last th accessed on August, Teo K, Chow CK, Vaz M, et al. The Prospective Urban Rural Epidemiology (PURE) study: Examining the impact of societal influences on chronic non-communicable diseases in low, middle and high-income countries. Am Heart J 9; 158:1-..Walker M, Whincup PH, Shaper AG. The British Regional Heart Study. Int J Epidemiol. ; 33: Schargrodsky H, Hernandez-Hernandez R, Champagne BM, et al, for the CARMELA study investigators. CARMELA: assessment of cardiovascular risk in seven Latin American cities. Am J Med. 8; 11:58-5. Address for correspondence Dr. Rajeev Gupta: rajeevg@satyam.net.in J. Preventive Cardiology Vol. 1 No. 1 August 11 15