Indian J. Prev. Soc. Med. Vol. 42 No.1, 2011

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1 ISSN Indian J. Prev. Soc. Med. Vol. 42 No.1, 2011 RISK FACTORS OF HYPERTENSION IN A RURAL AREA OF VARANASI CP Mishra 1, Sanjeev Kumar 2 ABSTRACT Background: Hypertension is emerging as an important public health problem. Primary prevention provides an attractive opportunity to interrupt and prevent the continuing costly cycle of managing hypertension and its complications. This in turn requires an understanding of risk factors of hypertension. Objectives: To pin point risk factors of hypertension in rural setup of Varanasi. Study Design: Community based case control study design Methods: In the three selected villages of a Community Development Block of Varanasi district, 3872 subjects of more than 30 year age were screened for detection of hypertension according to JNC 6 criteria; 93 cases and their age and sex matched controls (1:1) were selected. and controls were interviewed with the help of appropriate schedule to elicit information pertaining to socio demographic characteristics, behavioural parameters, disease related parameters, activity pattern and state anxiety and trait anxiety. Anthropometric measurements and 24 hour dietary recall method were used to assess the nutritional status. Results: Out of various variables significant in univariate analysis and having significant crude odds ratio for hypertension, educational status of high and intermediate level (AOR 6.79, CI ), upper middle and high socioeconomic status (AOR 14.04, CI ) and trait anxiety in the percentile range of >50% were significant with hypertension. Negative energy balance (> 500 kcal/day) had significant protective effect on the occurrence of hypertension. Conclusions: The findings of the study have immense potential for organising risk reduction programmes of hypertension. Key words: Risk factors, behavioural parameters, disease related parameters, activity pattern, state anxiety, trait anxiety INTRODUCTION An elevated arterial pressure is probably the most important public health problem in developed countries. It is common, asymptomatic, readily detectable, and usually easily treatable and often leads to the lethal complications if left untreated. It is now firmly established as risk factors for stroke, coronary heart disease (CHD), congestive heart failure, renal failure and peripheral vascular disease. 1 Cardiovascular diseases are the most common cause of the death world wide. 2 Epidemiological transition with increasing life expectancy and demographic shifts in population age profile combined with life style increases in the levels of cardio vascular risk factors is accelerating the CHD epidemic in India. 3 There has been a tenfold increase in CAD prevalence in the last three decades in Indian urbans. 4 Hypertension is an important risk factors for CHD. 5,6 It is predicted that noncommunicable diseases will account for 80% of the global burden of disease, causing 7 out of every 10 death today in developing countries, compared with less than half in Professor, Department of Community Medicine, Institute of Medical Sciences, BHU, Varanasi. 2. Assistant Professor, Department of Community Medicine, Peoples Medical College & Research Centre, Bhanpur, Bhopal (Corresponding author) Indexed in : Index Medicus (IMSEAR), INSDOC, NCI Current Content, Database of Alcohol & Drug Abuse, National Database in TB & Allied Diseases, IndMED, Entered in WHO CD ROM for South East Asia.

2 There is an evidence that lowering diastolic blood pressure by 5 to 6 mm of Hg results in 42% reduction in stroke and 15% reduction in the risk of CHD events. 8 However, without primary prevention, the problem of hypertension would never be solved. In fact, primary prevention provides an attractive opportunity to interrupt and prevent the continuing costly cycle of managing hypertension and its complications. Therefore an effective population wide strategy to prevent blood pressure rise with age and to reduce over all blood pressure levels, even by a little, could affect over all cardio vascular morbidity and mortality as much as or more than that of treating only those with established disease. 9 This requires an understanding of area specific risk factors of hypertension. Blood Pressure is a function of cardiac output and peripheral resistance, highly sensitive to a wide variety of internal and external physiological and socialpsychologic stimuli. There is a large body of empirical data indicating aggregation of hypertension and similarity of blood pressure levels within families. The risk factors of hypertension may be classified into non modifiable (viz. age, sex, genetic factors) and modifiable risk factors (e.g. obesity, dietary factors, alcohol intake, physical activity, environmental stresses etc.). Blood pressure rises with age in both sexes and rise is greater in those with higher initial blood pressure. Age probably represents an accumulation of environmental influences and the effects of genetically programmed senescence in body systems. Physical activity by reducing body weight and energy balance may have an indirect effect of hypertension. Psychological factors, personality traits and coping behaviour during anger and aggression may exert significant influence on blood pressure. With this background this study was undertaken to pin point risk factors of hypertension in rural setup of Varanasi. MATERIAL AND METHODS This study was undertaken in Chiraigaon Community Development Block of Varanasi District. A case control design was adopted for this study in a community setup. In the first stage one CD Block (i.e. Chiraigaon) was selected from 8 CD Blocks of Varanasi District by simple random sampling. In the second stage villages were stratified in to three strata (viz. <5km, 610 km, >10 km) from block headquarter and from each stratum one village was selected by simple random sampling. In selected villages subjects of >30 years of age (3872) were enrolled for the study. In the event of non availability of the subject during the first visit, two additional visits were made. In all blood pressure of 3569 (92.17%) subjects were measured with Sphygmomanometer as per criteria suggested by JNC6. 10 As blood pressure readings in many individuals are highly variable, the diagnosis of hypertension was made only after elevation was noted only after two readings. Overall prevalence of systemic hypertension was 13.06%. Corresponding value for male and female subjects were 13.16% and12.95% respectively. 11 Out of 240 male hypertensive, 48 subjects were selected as case by systemic random sampling. By adopting the same process, 45 female subjects were identified as case. In all 93 cases meeting the selection criteria were considered for the study. Known hypertensives on antihypertensive therapy were excluded and replacement samples were taken from the same age and sex group. Freshly diagnosed hypertensive with systolic blood pressure >140 and diastolic blood pressure>90 mm Hg were included. Age and sex matched community control were selected from the three villages considered for prevalence study. Age matching was done following the frequency for frequency matching within 5 years. and controls were selected in the ratio 1:1. and controls were interviewed with the help of predesigned and pre tested schedule to elicit information pertaining to socio demographic characteristics (viz. religion, caste, type and size of family, educational level, marital as well as socioeconomic status), behavioural parameters (i.e. Addiction), disease related parameters (Past illness of arthritis, family history of hypertension, family history of obesity, history of drug intake and, associated conditions). and controls were Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

3 subjected to anthropometry following standard technique. 12 Their weight was recorded using Libra weighing scale without using footwear and with minimal clothing. Accuracy of weighing scale was checked from time to time against known weight. Height of study subjects was recorded with the help of steel anthropometric rod with parallel bars. Body Mass Index (BMI) of each study subject was computed by their weight (in kg) divided by height 2 (in mt). Dietary intake of cases and control were assessed by 24 hours recall oral questionnaire method. Diatory intake in terms of macro and micro nutrients were computed by referring to guidelines suggested by Gopalan et al (2000) 13 and Swaminathan (1995). 14 Dietary practices of cases and controls were assessed by using interview schedule and by interviewing them. The activities performed by cases and controls in previous 24 hours and their duration were noted by interviewing them with the help of interview schedule. In this study, the multipliers suggested by Bouchard et al (1983) 15, Satyanarayan et al (1987) 16 and ICMR (1990), 17 have been taken for computation purpose. Utilizing the data on time spent on various activities and the corresponding multipliers, the rate of energy expenditure in terms of BMR units was found out mathematically. Rate of energy expenditure = timi/1440 where ti is the time, time spent (in minutes) for it activity and mi is the corresponding multiplier. and controls were evaluated for their state and trait anxiety. Each study subject was interviewed with the help of state anxiety and trait anxiety scale and their status was determined following guidelines suggested by Spielberger. 18 Data thus generated was analysed with the help of a PC using SPSS package. Statistical association of different parameters in cases and controls were tested by using x 2. Significant risk factors were examined through logistic regression analysis. 19 Crude as well as adjusted odds ratio was computed for different risk parameters. Confidence Interval were computed following Woolf method. 20 RESULTS and controls had similar age and sex composition. They did not differ significantly in terms of religion, caste, type and size of family and marital status. and controls did not differ significantly in terms of tobacco and alcohol consumption and addiction pattern. Results of the study are given below under following subheads [A] Socio Demographic Parameters and Odds of hypertension: As much as.63% cases and 63.43% controls were illiterate; Subjects with education, high school and intermediate were significantly (p) more in cases (.63%) than in controls (13.98%). In case of 47 (50.54%) and 32 (34.41%) cases per capita monthly income was between Rs and Rs. >1200 respectively; corresponding values for controls were 28 (30.12%) and 7 (7.53%). Income wise difference in cases and control were statistically significant (p). Fifty seven (61.29%) cases and 21 (22.58%) controls belonged to upper middle + high socioeconomic status. In comparison to illiterate cases, subjects with education high school and intermediate had higher odds (4.54; CI ) of hypertension. With reference to per capita income <600 rupees per month crude odds ratio (COR) for income categories PCI / and >1200 rupees per month were 6.95 ( ) and ( ), respectively. Odds ratio of hypertension was higher in lower middle+ middle (1.89, CI ), upper middle + high (7.92, CI ) socioeconomic status (Table 1). Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

4 Table 1: Socio demographic parameters and Odds of hypertension Test of significance No. % No. % 2 P value Educational status Graduate and above High school & intermediate Literate+ Primary+ Middle Illiterate (Reference) ( ) 4.54 ( ) 1.58 ( ) Per Capita Income (Rs / mth) > <600 (Reference) ( ) 6.95 ( ) Socioeconomic Status Upper Middle + High Lower Middle + Middle Very Low + Low (Reference) ( ) 1.89 ( ) <0.05 [B] Disease Related Parameters and Odds of hypertension: As much as 20.43% cases and 8.6% controls had arthritis in the past. Obesity was present in 7.03% cases and 2.15% controls (p>0.005). Family history of hypertension was present in 18.28% cases and 4.30% controls (p<0.01). Table 2: Disease related parameters and Odds of hypertension Test of significance No. % No. % 2 P value Past Illness of Arthritis Family history hypertension Family history of Obesity History of Drug Intake (NSAIDs) Associated Conditions Obesity ( ) 4.98( ) 3.61( ) 2.57( ) 2.75( ) <0.05 <0.01 < < < ( ) 5.87 <0.05 Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

5 Corresponding value for obesity were 10.75% and 3.22% (p<0.05). There existed no significant difference in cases and controls with respect to family history of diabetes mellitus (5.38% versus 2.15%) and stroke (3.22% verses 1.08%). There existed significant (p<0.05) difference in the use of NSAIDs by cases (23.66%) and controls (10.75%). They had similar pattern of use of oral contraceptive pills, corticosteroids nasal decongestants and tricyclic antidepressants. Arthritis and diabetes mellitus were associated in 18.28% and 3.23% cases respectively; corresponding values for controls were 9.68% and 2.15%. Obesity as associated conditions was present in 12.90% cases and 3.23% controls (p<0.05). Crude odds ratios revealed significant association (Table2) of hypertension with past illness of arthritis (2.73, CI ), family history of hypertension (OR 4.98, CI ), NSAIDs intake (OR 2.57, CI ), associated conditions (OR 2.75, CI ), presence of obesity (OR 4.44, CI ). Table 3: Nutrition and dietary practices related parameters and Odds of hypertension Test of significance No % No % 2 P value Body Mass Index (Kg/m 2 ) >23 <23 Type of physical activity Sedentary worker Moderate worker Heavy worker (Reference) Energy Intake (K cal/ day) < <2000 (Reference) Energy Expend (K cal / day) < >2800 (Reference) Energy Balance Positive Negative Positive Energy Balance > <500 Negative Energy Balance (Reference) Negative Energy Balance > <500 Positive Energy Balance (Reference) Nature of diet Nonvegetarian Vegetarian Timings of Meal Irregular Fixed Frequency of meal per day >3 < ( ) ( ) 2.71( ) 2.67( ) 2.77( ) 4.77( ) 3.15( ) 3.92( ) 4.46( ) 2.32( ) 4.95( ) 0.12( ) 0.24( ) 0.76( ) (IIII: 4.03) (IIIII: 10.05) <0.05 <0.01 <0.01 < < ( ) ( ) 4.72 < ( ) 5.44 <0.05 Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

6 [C] Nutrition and Dietary practices related parameters and Odds of hypertension: and controls differ significantly with respect to nutritional status. Forty six (49.46%) cases and 13 (13.98%) controls were either overweight or obese as per WHO criteria for Asian population. In 3.23% cases and 40.86% controls BMI was less than 18.5 (i.e. undernourished). Sixty seven (72.04%) cases and 42 (45.16%) controls were sedentary workers. and controls differed significantly (P) in terms of physical activity In 13 (13.98%) cases and 9 (9.68%) controls, calorie consumption was more than 2800 kcal/ day. and controls differed significantly (p<0.01) in their calorie intake. As much as 27.96% cases and 51.51% controls had calorie consumption less than 2000 Kcal/day. Their existed significant (p<0.01) difference in energy expenditure of cases and controls. As much as 56.98% cases and % controls spent less than 2000 Kcal/day. Subjects with positive energy balance were significantly (p) more in cases (76.34%) than in controls. Positive and negative energy balances of 1000 Kcal/day were in 26.88% and 5.38% cases respectively; corresponding values for controls were 13.98% and 25.81%. Strict vegetarianism was practiced by 18.28% cases and 46.24% controls. They differ significantly (p<0.01) in terms of nature of diet. Irregular timings of meal was observed significantly (p<0.05) more in cases (68.82%) than in controls (48.39%). and controls differ significantly (p< 0.05) in terms of frequency of meals/day. In comparison to cases with BMI <23 kg/m 2, subjects with BMI >23 kg/m 2 had significant higher odds of hypertension (COR 6.02, CI ). Taking heavy workers as reference it was observed that sedentary workers had significantly (p ) higher odds (COR 6.38; CI ) of hypertension. For cases with energy intake and >2800 kcal/day COR were 2.77 ( ) and 2.67 ( ), respectively. Subject with energy expenditure <2000 and kcal/day had higher odds of hypertension with reference value of >2800 kcal/day. In comparison to subjects with negative energy balance, cases with positive balance had significantly (p) higher odds of hypertension (OR 3.92; CI ), computations of COR and CI taking negative energy balance as reference value, increasing odds of hypertension was observed in other groups. Reverse trend prevailed when positive energy balance was taken as reference (Table3). Significantly higher odds of hypertension prevailed for nonvegetarians (COR 3.84; CI ) and subjects with frequency of meals >3 per day (COR 2.57; CI ) and with irregular timings of meal. [D] Macronutrients intake and Odds of hypertension: In 77.42% cases and 59.41% controls protein consumption was more than 50 grams/day (p <0.01). Saturated fat and salt intake were significantly more in cases than in controls. Consumption of unsaturated fats and oils had been similar in cases and controls (p ). In case of 13.98% cases and 12.9% controls fibre intake was >20 gm/day. They did not differ significantly (p) in their fibre intake (Table4). Higher odds of hypertension prevailed for subjects with protein intake >50g/day, saturated fat intake > 5 g/day (p). COR of hypertension for unsaturated fat and oil and dietary fibre intake were not statistically significant (Table4). [E] Micronutrients intake and Odds of hypertension: Sixty one (65.59%) cases and 53 (56.9%) controls had calcium intake 400 ml/day (p). As much as 35.48% cases and 18.28% controls consumed 10 gm of salt/day. They differ significantly in their salt intake. However, sodium intake other than in the form of salt had been similar in cases and controls. As much as 65.59% cases and 82.80% controls had potassium intake >1000 mg/day (p). In 54.84% cases and 39.79% controls magnesium intake was <150 mg/day (p). Odds ratio for hypertension was significantly high for salt consumption > 5g/day. COR of the hypertension for calcium, potassium and magnesium were not statistically significant (Table5). Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

7 Table 4: Macronutrient intake and Odds of hypertension Test of significance No % No % 2 P value Protein Intake (g/day) >50 < ( ) 7.17 <0.01 Saturated Fat intake (g/day) >5 < ( ) <0.01 Unsaturated fat and oil Intake (g/day) >10 < ( ) 1.89 Fibre intake (g/day) <20 > ( ) 0.05 Table 5: Micronutrient intake and Odds of hypertension Test of significance No % No % 2 P value Calcium Intake (mg/day) <400 > ( ) 1.45 Salt consumption (g/day) > <5 (Reference) ( ) 4.48( ) Sodium intake other than in the form of salt (mg/day) >100 < ( ) 3 Potassium intake (mg/day) < >2500 (Reference) ( ) 0.91( ) Magnesium intake (mg/day) < >350 (Reference) ( ) 1.23(0.4.08) [F] Psychological status and Odds of hypertension: with state and trait anxiety >75 percentile range were 20.43% and 16.13%, respectively; corresponding values for controls were 5.38% and 3.23%. In 31.18% cases and 79.57% controls state anxiety was in 50 percentile ranges. Trait anxiety of % cases and 80.64% were 50 percentile ranges. They differed significantly (p) in terms of state and trait anxiety. In compression to subjects with Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

8 state anxiety (<50 percentile range) significant odds of hypertension was observed in subjects with state anxiety in the range of and >75. Higher odds were also observed for trait anxiety in these categories (Table6). Table6: Psychological status and Odds of hypertension Test of significance No % No % 2 P value State Anxiety (Percentile range) > <50 (reference) ( ) 8.20 ( ) Trait Anxiety (Percentile range) > <50 (reference) ( ) 4.80 ( ) [G] Adjusted Odds Ratios (AOR) and confidence intervals of risk factors of hypertension: Per capita income being integral components of SES was not considered for logistic regression analysis. The four variables found significant in the logistic model had sensitivity and specificity of 84.6% and 81.7% respectively, in classifying cases and controls correctly. Out of various variables significant in univariate analysis and having significant crude odds ratio for hypertension, educational status of high and intermediate level (AOR 6.79, CI ), upper middle and high socioeconomic status (AOR 14.04, CI ) and trait anxiety in the percentile range of >50% were significant with hypertension. Negative energy balance had significant protective effect on the occurrence of hypertension (Table7). Table7: Adjusted Odd s ratio (AOR) and confidence interval of risk factor of hypertension Risk Factors Educational status Graduate and above High school and intermediate Literate+ Primary+ Middle Illiterate (Reference) Socioeconomic Status Upper Middle + High Lower Middle + Middle Very Low + Low (Reference) Negative Energy Balance > <500 Positive Energy Balance (Reference) Trait Anxiety (Percentile range) > <50 (reference) Beta estimate S.E. (AOR) 95% CI Chi Square Probability Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

9 DISCUSSION In recent decades the prevalence of non communicable disease and their antecedent risk factors are rising in developing countries. These changes are caused to a large extent by dietary changes in relation to socioeconomic and environmental conditions. Among the various socioeconomic factors education is a marker of socioeconomic status. It is expected that with increasing level of education, the magnitude of hypertension will increase in a given area. A study conducted in the rural area could not find significant association between education and hypertension 22. Contrary to this significant association has been observed in this study between educational status and hypertension. In conformity with the finding of several workers, 22, 23 in this study higher risk of hypertension was observed in upper and middle socioeconomic groups. Per capita income being integral component of SES, it is likely to exhibit same trend as SES and this observation is supported by other studies as well 22, 24. It is generally accepted that approximately 30% of the variance of blood pressure is attributable to genetic heritability and 50% to environmental influences. Cultural heritability and residual variance each account for 10% variance 25. Higher odds of hypertension and obesity call for close scrutiny of environmental influences. Obesity predisposes to arthritis as well. It is interesting to note that arthritis has been significantly more in cases than controls and so was use of NSAIDs (table2) which is considered as a risk factor for hypertension. The relation of weight, weight gain, BMI with hypertension has been explored to a considerable extent 22. Although more energy intake predispose to hypertension, one has to consider another dimensions of it. It is the total energy balance which is responsible for obesity and therefore in any study it becomes imperative to compute energy expenditure on the basis of physical activity. In the present observation cases had significantly more intake of energy and thereby more positive energy balance. CORs of hypertension (table3) amply highlights linkage of energy balance with hypertension. Non vegetarian diet may be associated with occurrence of hypertension, probably due to increased sodium intake. Finding of univariate analysis supports this observation. As per this study, irregular timing of meal and frequency of meals >3 per day also predispose to hypertension. Protein intake has been significantly more in cases than in controls (table4). High intake of saturated fat has been identified as a risk factor for hypertension 22 as observed in the present observation too. and controls had similar pattern of consumption of unsaturated fat and oil as well as dietary fibres. This study could not substantiate the protective role of dietary fibres for occurrence of hypertension. The relationship between sodium intake and hypertension remains controversial. Direct correlation between salt intake and hypertension has been reported in literature 9, 26. Higher CORs have been observed for subjects consuming more salt (table5). The beneficial effect of potessium 9, 27, calcium 9 and magnisium 9 has not been observed on the occurrence of hypertension in the present study. Results given in table6 clearly state the role of state and trait anxiety in occurrence of hypertension. CORs have been more in higher percentile ranges. Logistic regression modal pinpoints higher educational level and socioeconomic status as well as trait anxiety as risk factors of hypertension. However, negative energy balance exerted protective effect on it. These findings have significant policy implications and provide basic framework for programme directions for primordial prevention of hypertension. Due emphasis should be given for promotion of healthy life styles 28 which include eating of balanced diet, regular physical exercise and stress reduction activities as suggested by a group of researchers as well 29. REFERENCES 1. Kannd WB. Coronary risk factors: an overview, in: Cardiovascular medicine edited by Willerson JT, Cohn J N: Churchill Livingstore 1995, New York, NY, 1995: Murray CH, Lopez AD. Global mortality, disability and contribution of risk factors: Global burden of disease study. Lancet 1997; 349: Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

10 3. Reddy KS, Yusuf S. Emerging epidemic of cardiovascular disease in developing countries, Circulation 1998, 97: Singh RB, Jonlinson B, Thomos N, Sharma R. Coronary artery disease and coronary risk factors: The south Asian Paradox. J. Nutrition Environ Med 2001; 11: Chadha SL, Radhakrishnan S, Ramchandran K, Gopinath N. Epidemiological study of coronary disease (CHD) in rural population of Gurgaon district (Haryana State). Indian Journal of Community Medicine 1989; 15(4): Zodpey SP, Kulkarni HR, Vasudeo ND, Kulkarni SW. Risk factors of coronary heart disease: A case control study. Indian Journal of Community Medicine. 1998; 23 (1): Boutayeb A, Bouteyab S. The burden of Non communicable disease in developing countries: International Journal of Equity Health. 2005; 4:2. 8. Collins, Peto R, Mac Mohan S et al. Blood pressure, stroke and coronary artery diseases. Part Z, short term reduction in blood pressure, overview of randomized drug trial in their epidemiological context. Lancet 1990; 335: National Institute of Health. National High Blood Pressure Education Programme. The sixth report of Joint National Committee on Prevention, detection, evaluation and treatment of high blood pressure. Bethesda, USA, NIH publication No. 98, P Joint National Committee. The fifth report of the Joint National Committee on detection, evaluation and treatment of high blood pressure (JNCV), Arch Intern Med 1993; 153: Kumar S, Mishra CP. Prevalence sand spectrum of hypertension i n a rural area. Kathmandu University Medical Journal. 2008; 6(2); Jilliffe DB. The assessment of nutritional status of the community. World Health Organization, Geneva, 1966; Gopalan C, Rama Sastri BV, Balasubramanian. Nutritive value of Indian foods. NIN ICMR, Hyderabad, 2000; Swaminathan N. Nutritive value of common Indian food calculations. Advanced Textbook on Food & Nutrition.1995; 2: Bouchard C, Trembly A, Leblanc C, Lortic G, Savart R, Theriault GA. Method to assess energy expenditure in children and adult. Amer. J. Clinical Nutrition. 1983; : Satyanarayan K, Vankata Raman Y, Rao MS, Anuradha A, Narasinga Rao BS. Quantitative assessment of physical activity and energy expenditure pattern among rural working woman. Update Growth. 1987; ICMR. Nutrient requirement and dietary allowances for Indians. A report of the expert group of the Indian council of medical research, 1990; Spielberger CD. Preliminary manual for the StateTrait Personality Inventory, University of South Florida, Tampa, FL Thomson WD. Statistical analysis of case control study epidemiological reviews.1994; 16(1): Woolf B. On estimating the relation between blood group and diseases. Ann Hum Genet, 1995; 19: Svetkey L P, Moore T J, Simons Morton D C, Apple L J, Bray GA et al. Angiotesinogen genotype and blood pressure response in the dietary approaches to stop hypertension (DASH) study, J Hypertension, 2001, 19: Goel NK. Epidemiology of hypertension in a rural community of Varanasi District. Thesis submitted for the degree of MD (PSM) of Banaras Hindu University. 1994; pp Gupta SP, Siwach SN, Noda VK. Epidemiology of hypertension. Ind HJ. 1977; 29: Dash SC, Swain PK, Sunderan KR, Malhotra KK. Hypertension epidemiology in an Indian Tribal population. JAPI, 1986, 34(8) : Word R. Familial aggregation and genetic epidemiology of blood pressure. In Hypertension: Pathophysiology, Diagnosis and Management edited by Laragh JH and Bernner BM. Raven press; 1990: Massie Barry M. Systemic Hypertension. CMDT, 2003: Intersalt Cooperation Research Group. Intersalt: an international study of electrolyte excretion and blood pressure: Results for 24 hours urinary sodium and potassium excretion. BMJ, 1988; 297: Pickrung TG. New guidelines on diet and blood pressure. Hypertension, 2006, 47: Ramsay SE, Whincup PH, Shaper AG, Wannamethee SG. The relation of body composition and adiposity measures to ill health and physical disability in elderly man. Am J Epidemiology, 2006, 164: Indian J. Prev. Soc. Med Vol. 42 No January March, 2011

11 Indian J. Prev. Soc. Med Vol. 42 No January March, 2011