Coronary heart disease has assumed epidemic proportions

Transcription

1 Original Article Serial Epidemiological Surveys in an Urban Indian Population Demonstrate Increasing Coronary Risk Factors Among the Lower Socioeconomic Strata R Gupta, VP Gupta, M Sarna, H Prakash, Shweta Rastogi, KD Gupta Abstract Objective : To determine trends of coronary risk factors in an Indian urban population and their association with educational level as marker of socioeconomic status. Methods : Two successive coronary risk factor surveys were performed in randomly selected individuals. In the first study (in 1995) 2212 subjects (1415 men, 797 women) and in the second (in 2002) 1123 subjects (550 men, 573 women) were studied. Details of smoking, physical activity, hypertension, diabetes, coronary heart disease, body-mass index, waist-hip ratio, blood pressure and electrocardiography were evaluated. Fasting blood was examined for lipid levels in 297 (199 men, 98 women) in the first and in 1082 (532 men, 550 women) in the second study. Educational status was classified into Group 0: no formal education, Group I : 1-10 years, Group II : years, and Group III : >16 years. Current definitions were used for risk factors in both the studies. Results : Prevalence of coronary risk factors, adjusted for age and educational status, in the first and second study in men was smoking/tobacco in 38.7 vs. 40.5%, leisure time physical inactivity in 70.8 vs. 66.1%, hypertension ( 140 and/or 90 mm Hg) in 29.5 vs. 33.7%, diabetes history in 1.1 vs. 7.8%, obesity (body-mass index 25 Kg/m 2 ) in 20.7 vs. 33.0%, and truncal obesity (waist:hip > 0.9) in 54.7 vs. 54.4%. In women, tobacco use was in 18.7 vs. 20.5%, leisure time physical inactivity in 72.4 vs. 75.3%, hypertension in 36.9 vs. 33.7%, diabetes history in 1.0 vs. 7.3%, obesity in 19.9 vs. 39.4%, and truncal obesity (waist:hip > 0.8) in 70.1 vs. 69.2%. In men, high total cholesterol 200 mg/dl was in 24.6 vs.37.4%, high LDL cholesterol 130 mg/dl in 22.1 vs. 37.0%, high triglycerides 150 mg/dl in 26.6 vs. 30.6% and low HDL cholesterol < 40 mg/dl in 43.2 vs. 54.9%; while in women these were in 22.5 vs. 43.1%, 28.6 vs. 45.1%, 28.6 vs. 28.7% and 45.9 vs. 54.2% respectively. In the second study there was a significant increase in diabetes, obesity, hypertension (men), total- and LDL cholesterol and triglycerides and decrease in HDL cholesterol (p< 0.05). In the first study with increasing educational status a significant increase of obesity, total cholesterol, LDL cholesterol and triglycerides and decrease in smoking was observed. In the second study increasing education was associated with decrease in smoking, leisure-time physical inactivity, total and LDL cholesterol, and triglycerides and increase in obesity, truncal obesity and hypertension (Least-squares regression p< 0.05). Increase in smoking, diabetes and dyslipidaemias was greater in the less educated groups. Conclusions : Significant increase in coronary risk factors- obesity, diabetes, total-, LDL-, and low HDL cholesterol, and triglycerides is seen in this urban Indian population over a seven year period. Smoking, diabetes and dyslipidaemias increased more in low educational status groups. INTRODUCTION Coronary heart disease has assumed epidemic proportions in developing countries. 1,2 Demographic shifts in Monilek Hospital and Research Centre, Jaipur, Mahatma Gandhi National Institute of Medical Sciences, Jaipur , and University of Rajasthan, Jaipur Received : ; Revised : ; Accepted : population age-profile combined with increasing trends in major coronary risk factors- smoking, sedentary lifestyle, hypertension, hypercholesterolaemia and diabetes- are accelerating this epidemic. 2 Studies in developed countries have shown that declining trends in coronary risk factors are associated with a decreasing coronary heart disease mortality as well as incident acute myocardial infarctions. 4 On the other hand in developing countries no systematic studies of risk 470 JAPI VOL. 51 MAY 2003

2 factor trends exist although there appear to be increasing prevalence of coronary risk factors as reported in some studies and reviews. 4-6 Coronary heart disease is a malady of low socioeconomic status subjects in developed countries. Studies from Britain, Western Europe and North America have consistently shown that since mid and late 1970 s the coronary risks increased in low socioeconomic status individuals and coronary mortality is more than 2-3 times in them as compared to high socioeconomic status subjects. 7 The causes of these differences have been extensively investigated. The current opinion is that the low socioeconomic status subjects in developed countries have a higher prevalence of smoking, obesity, truncal obesity, dyslipidaemia and faulty diet. Role of harmful social gradients and stressful living conditions and associated psychological factors of chronic anxiety, hostility, and depression have also been found significant. 8 Most studies from developing countries have not focussed on coronary risks in different socioeconomic status individuals. Some studies from India up to late-twentieth century demonstrated that coronary heart disease was more prevalent in high-income groups. 9 Similar results were observed from other parts of Asia and Eastern Europe. 1,7 Gupta et al reported a higher prevalence of coronary heart disease, smoking, and hypertension among the illiterate in a rural Indian population. 10 Pais et al reported a higher incidence of acute myocardial infarction among the illiterate in a case-control study. 11 Misra et al reported high prevalence of coronary risk factors in an Indian urban slum population. 12 Studies from other parts of Asia are, however, not consistent. Dowse et al 4 from Mauritius did not observe any association of low socioeconomic status with coronary risks and Yu et al 5 from China reported greater prevalence of smoking, obesity and hypertension in those with higher education. We performed two successive epidemiological studies, seven years apart, in an Indian urban population to study trends in prevalence of coronary risk factors and evaluated influence of education as a marker of socioeconomic status on these risk factors. METHODS The institution ethics committee approved the studies. A proforma was prepared that incorporated information regarding demographic, anthropometric and clinical variables. This included various lifestyle factors such as education and type of job. Details of major cardiovascular risk factors such as smoking, alcohol intake, amount of physical activity, diabetes and hypertension were inquired. The physical examination emphasized measurement of height, weight, waist-hip ratio and blood pressure. Height was measured in centimetres and weight in kilograms using calibrated spring-balance. Supine waist girth was measured at the level of umbilicus with person breathing silently and standing hip girth was measured at inter-trochanteric level. The blood pressure was measured using standard mercury manometer. At least two readings at 5 minutes intervals as per World Health Organisation guidelines 13 were recorded. If a high blood pressure ( 140/90) was noted a third reading was taken after 30 minutes. The lowest of the three readings was taken as blood pressure. A 12-lead routine electrocardiogram was performed on all persons using proper standardization. Fasting blood sample was obtained for estimation of glucose, total-, high density lipoprotein (HDL), and low density lipoprotein (LDL) cholesterol and triglycerides using previously standardised techniques. 10 The study was designed to investigate people at random and to cover large and varied areas of Jaipur, India with a view to include persons from all walks of urban life. Jaipur is divided into 70 wards according to publication of Jaipur Municipal Council. Randomly chosen wards from different regions of the city were identified so as to cover different socioeconomic groups. We studied population in colonies of Jawahar Nagar, Janta Colony, Ramganj Bazar, Chandpole Bazar, Moti-Doongri Road and Jaipur South in both the studies. Details of the population in these wards were available from the Voters Lists. The men:women ratio in the adult population (>20 years) of Jaipur is 1000:865 (Census of India, 1991). In the first study in we randomly selected 500 subjects from each locality (men 268, women 232) and a total of 3000 subjects (men 1608, women 1392) were invited for participation. In the second study in we invited 300 subjects (240 men, 160 women) from each locality. The total study sample was 1800 with a population proportionate gender ratio and 960 men and 840 women were invited for participation. No effort was made to enroll the same individuals for both the studies as also done in a recent Chinese study. 5 The studies were preceded by meetings with local leaders who cooperated in identifying and ensuring participation of selected subjects. Diagnostic criteria : Similar criteria were used in the first and the second studies. Smokers in India consume tobacco in various forms- rolled tobacco leaves (bidi), Indian pipe (chillum, hookah), cigarettes and tobacco-chewing -and more than one form is used by many making it difficult to accurately measure the amount of tobacco consumed. Therefore, users of all types of tobacco products and present and past smokers have been included in smoker category. Physical activity was measured by asking about both workrelated and leisure-time activities, a person who engaged in > 30 minutes of moderate grade physical activity at least 3 times/week was classified as physically active. Hypertension was diagnosed when systolic blood pressure was 140 mm Hg and/or diastolic blood pressure 90 mm Hg. Body mass index (weight in Kg)/(height in metres) 2 was calculated and obesity defined as BMI 25 kg/m 2. Truncal obesity was diagnosed when waist-hip ratio was > 0.9 in males and > 0.8 in females. Dyslipidaemia was defined by the presence of high total cholesterol ( 200 mg/dl), high low-density lipoprotein cholesterol ( 130 mg/dl), low high-density lipoprotein cholesterol (< 40 mg/dl) or high triglycerides ( 150 mg/dl) according to American National Cholesterol JAPI VOL. 51 MAY

3 Education Program-III guidelines and reported earlier. 15 Statistical analysis : The data were pooled and computerised. SPSS V4.0.1 (SPSS Inc, Chicago, USA) and GB-Stat V7.0 (Dynamic Microsystems, Silver Spring, USA) programs were used for data analysis. The prevalence rates are given in percent. Various numbers are given as mean ± 1 standard deviation. There was difference in age-distribution in the two studies (Table 1) and risk factor comparison in the first and the second study was performed after ageadjustment using the direct method. Continuous variables have been compared using t-test and categorical variables by χ 2 test. Educational status has been classified into four groups in both males and females. Group 0 with no years of formal education, Group I : 1-10 years, Group II : years, and Group III 16 years. Age- and educational-level adjusted prevalence of various coronary risk factors after categorisation into different educational strata was determined. Correlation of educational level with different risk factors was determined using non-parametric Spearman s rho. Trends in prevalence of coronary risk factors in different educational groups were determined using least-squares method and r 2 calculated. P values <0.05 have been considered significant. RESULTS The overall response rate in the first study was 73.7% (2212/3000), 1415/1608 (88.0%) in men and 797/1392 (57.3%) in women. Fifteen percent of the enrolled first study subjects were invited for participation for fasting blood lipid estimation and the response rate was 199/212 (93.9%) in men and 98/120 (81.7%) in women. In the second study the overall response rate was 62.4% (1123/1800), in men it was 550/960 (57.3%) and in women 573/840 (68.2%). All the Table 1: Number of subjects in various educational groups Educational Men Women Class First Study Second Study First Study Second Study N=1412 N= 550 N= 797 N=573 Total Numbers Group (33.4) 103 (18.7) 561(70.4) 213 (37.7) (Illiterate) Group1 I38 (27.1) 182 (33.1) 61 (7.6) 163 (28.4) (1-10 years) Group II 363 (25.7) 202 (36.7) 88 (11.0) 161 (28.1) (11-15 years) Group III 195 (13.8) 63 (11.5) 87 (10.9) 36 (6.3) ( 16 years) Lipid Values N= 199 N= 532 N= 98 N= 550 Group 0 66 (33.2) 96 (18.0) 63 (63.9) 211 (37.7) (Illiterate) Group I 41 (20.6) 181 (34.0) 34 (35.1) 158 (28.3) (1-10 years) Group II 48 (24.1) 198 (37.2) 1 (1.0) 156 (27.9) (11-15 years) Group III 44 (22.1) 57 (10.7) - 34 (6.1) ( 16 years) Table 2: Coronary risk factor prevalence adjusted for age and educational status in first (1995) and second (2002) study Men Women Risk Factors 1995 study 2002 study 1995 study 2002 study N=1415 N=550 N=797 N=573 Smoking/tobacco 548/ / / /573 (38.7) (40.5) (18.7) (20.5) Leisure-time 1003/ / / /573 physical inactivity (70.9) (66.1) (72.4) (75.3) Diabetes (History) 15/ /550 8/797 42/573 (1.1) (7.8)* (1.0) (7.3)* Obesity (BMI 293/ / / / Kg/m 2 ) (20.7) (33.0)* (19.9) (39.4)* Truncal obesity 128/ / / /573 Males >0.9, (54.7) (54.4) (70.1) (69.2) Females >0.8 Hypertension 417/ / / /573 ( 140/90) (29.5) (33.7) (36.9) (33.7) Total Cholesterol ± ± 43* ± ± 41* High cholesterol 49/ /532 22/98 243/ mg/dl (24.6) (34.4)* (22.5) (43.5)* LDL cholesterol ± ± 39* ± ± 39* High LDL choles- 44/ /532 28/98 254/559 terol >130 mg/dl (22.1) (34.2)* (28.6) (45.4)* HDL cholesterol 43.1± ± 8* 44.8 ± ± 9* Low HDL choles- 86/ /532 45/98 303/559 terol >40 mg/dl (43.2) (53.4)* (45.9) (54.2)* Triglycerides 126.1± ± 79* ± ± 62* High triglycerides 53/ /532 28/98 160/559 (>150) mg/dl (26.6) (30.6)* (28.6) (28.7)* Numbers in parentheses are percent. * P < 0.05 enrolled subjects were invited for blood lipid estimations and the response rates in men was 523/550 (95.1%) and in women 559/573 (97.6%). Prevalence of major coronary risk factors, adjusted for age and educational status, in the first and the second studies is shown in Table 2. In men, a significant increase was seen in the prevalence of self-reported diabetes, obesity, hypertension, high total cholesterol, high LDL cholesterol, and low HDL cholesterol (p<0.01). There was no significant change in smoking, leisure-time physical inactivity, truncal obesity and hypertriglyceridaemia prevalence. In women a significant increase was seen in the prevalence of diabetes, obesity, high total cholesterol, high LDL cholesterol and low HDL cholesterol. There was no significant change in truncal obesity, hypertension and high triglycerides (Figure 1). Spearman s correlation analysis showed that in the first study there was a significant negative correlation of educational level with smoking in men (rho = -0.21) and women (-0.24). A significant positive correlation was present with body-mass index (men 0.18, women 0.11), truncal obesity (men 0.13, women 0.16), total cholesterol (men 0.12, women 0.12) and triglycerides (men 0.19, women 0.14). In the second study there was a significant negative correlation of level of education with smoking (men -0.47, women -0.36), total cholesterol (men -0.14, women -0.29), LDL cholesterol (men -0.15, women -0.16), triglycerides (men -0.14, women -0.25). A positive correlation was 472 JAPI VOL. 51 MAY 2003

4 Fig. 1 : Age- and educational status-adjusted risk factor comparisons in the first study (1995-light shade) and the second study (2002-dark shade). In both men and women there is a significant increase in prevalence of obesity, diabetes, high total cholesterol (Chol >200 mg/dl), high LDL cholesterol (>130 mg./dl) and low HDL cholesterol (<40 mg/dl) (p<0.001) and not in other risk factors. observed with systolic BP (men 0.20), diastolic BP (men 0.28, women 0.23), body-mass index (men 0.40, women 0.27), and waist-hip ratio (men 0.23). Prevalence of coronary risk factors adjusted for age and educational status in different educational groups in the first and the second studies are shown in Table 3 and Figure 2. In the first study trend analyses (least-squares regression, r 2 ) show a significant decrease in smoking (men 0.74, women 0.82) and increase in obesity (men 0.90) with increasing education. In the second study there is declining trend of JAPI VOL. 51 MAY

5 Table 3: Trends in educational status and coronary risk factors in first (1995) and second (2002) study and absolute change in risk factors Groups Men Women 1995 study 2002 study Change (95% CI) 1995 study 2002 study Change (95% CI) Smoking Group (44.0) 56 (54.4) (0.2 to 21.0) 135 (24.1) 60 (28.2) +4.1 (-2.8 to 11.0) Group I 198 (51.6) 78 (42.9) -8.7 (-17.5 to 0.1) 14 (22.9) 5 (3.1) (-11.6 to -28.0) Group II 107 (29.5) 52 (28.7) -0.8 (-8.6 to 7.0) 1 (0.6) +0.6 Group III 35 (17.9) 15 (23.8) +5.9 (-5.3 to 17.1) 1 (2.8) +2.8 r 2 (p value) 0.74 (0.137) 0.97 (0.016) 0.82 (0.095) 0.60 (0.222) Leisure Time Physical Inactivity Group (86.7) 92 (89.3) +2.6 (-4.5 to 9.7) 454 (80.9) 190 (89.2) +8.3 (2.4 to 14.2) Group I 271 (70.6) 117 (64.3) -6.3 (-14.5 to 1.9) 34 (55.7) 96 (58.9) +3.2 (-11.3 to 17.7) Group II 198 (54.5) 102 (50.5) -4.0 (-12.6 to 4.6) 47 (53.4) 64 (39.8) (-0.7 to -26.5) Group III 123 (63.1) 27 (42.9) (-6.2 to -34.2) 47 (48.3) 12 (33.3) (-34.3 to 4.3) r 2 (p value) 0.67 (0.179) 0.97 (0.016) 0.79 (0.112) 0.92 (0.038) Obesity Group 0 80 (16.9) 13 (12.6) +4.3 (-3.5 to 12.1) 91 (16.2) 72 (33.8) (11.2 to 24.0) Group I 79 (20.6) 58 (31.9) (3.7 to 18.9) 19 (31.1) 84 (51.5) (5.7 to 35.1) Group II 78 (21.5) 100 (49.5) (20.0 to 36.0) 25 (28.4) 109 (67.7) (26.3 to 52.3) Group III 56 (28.7) 34 (53.9) (11.7 to 38.7) 24 (27.6) 21 (38.3) (-7.2 to 28.6) r 2 (p value) 0.90 (0.051) 0.94 (0.029) 0.38 (0.383) 0.07 (0.734) Truncal Obesity Group 0 27/54 (50.0) 40 (38.8) (-27.5 to 5.1) 92/125 (73.6) 147 (69.0) -4.6 (-14.7 to 5.5) Group I 48/78 (61.5) 92 (50.5) (-24.2 to 2.2) 12/19 (63.2) 93(57.1) -6.1 (-29.6 to 17.4) Group II 44/87 (50.6) 137 (67.8) (5.0 to 29.4) 13/21 (61.9) 127(78.9) 17.0 (-2.2 to 36.2) Group III 20/33 (60.6) 47 (74.6) (-5.3 to 33.3) 17/28 (60.7) 25 (69.4) 8.7 ((-14.8 to 32.2) r 2 (p value) 0.19 (0.566) 0.98 (0.012) 0.76 (0.128) 0.11 (0.667) Diabetes History Group 0 7 (6.8) (0.4) 14 (6.6) +6.2 (3.2 to 8.5) Group I 8 (2.1) 16 (8.8) +6.7 (3.1 to 10.3) 4 (6.6) 20 (12.3) +5.7 (-3.4 to 14.8) Group II 1 (0.3) 16 (7.9) +7.6 (4.7 to 10.5) 2 (2.3) 12 (7.3) +5.0 (-0.9 to 10.9) Group III 6 (3.1) 5 (7.9) +4.8 (-0.3 to 10.5) - 3 (8.3) +3.0 r 2 (p value) 0.43 (0.345) 0.14 (0.621) 0.09 (0.807) 0.00 (0.995) Hypertension Group (29.4) 20 (19.4) (-0.5 to -19.5) 188 (38.5) 62 (29.1) -9.4 (-1.8 to 17.0) Group I 126 (32.8) 74 (40.7) +7.9 (-0.5 to 16.3) 33 (53.2) 75 (46.0) -7.2 (-21.9 to 7.5) Group II 94 (25.9) 76 (37.6) (3.8 to 19.6) 28 (31.8) 59 (35.8) +4.0 (-8.3 to 16.3) Group III 58 (29.7) 30 (47.4) (4.2 to 31.2) 18 (20.7) 19 (52.8) (14.3 to 43.9) r 2 (p value) 0.08 (0.726) 0.76 (0.127) 0.51 (0.289) 0.56 (0.253) Numbers in parentheses are percent unless mentioned otherwise. r 2 = squares r by least squares regression. smoking (men 0.97, women 0.60), leisure-time physical inactivity (men 0.97, women 0.92) and increasing trend of obesity (men 0.94), truncal obesity (men 0.98, women 0.76)and hypertension (men 0.76, women 0.51) with increasing education. In the second study as compared to the first, the trends in smoking and diabetes increased while positive trends of obesity, truncal obesity and hypertension did not change significantly. For lipids, the trend analyses (Figure 3) demonstrate that in men in the first study there was an increasing trend (r 2 ) in mean levels of total cholesterol (0.83), LDL cholesterol (0.95), and triglycerides (0.90), with increasing education. This trend reversed in the second study in men for total cholesterol (0.58), LDL cholesterol (0.26), and triglycerides (0.86). Similar results are seen for women. Sub-group differences (Table 3) showed that in men smoking or tobacco use increased the most in the illiterate group (+10.4%). Leisure-time physical inactivity levels were higher among the illiterate and less educated groups and inactive lifestyle declined the most among Group III men (- 20.2%). Obesity or overweight increased in all the educational groups in both men and women, greater increase was in the more literate subjects. Truncal obesity prevalence showed a mixed change among various educational groups. The prevalence of self-reported diabetes increased significantly among the illiterate (absolute increase men 6.8%, women 6.2%) and men in Groups I (+6.7%) and II (+7.6%). Prevalence of hypertension decreased significantly in illiterate men (-10.0%) and women (-9.4%) and increased significantly in Groups II (men +11.7%) and III (men +32.1%, women +17.7%). In men, mean levels of total cholesterol and LDL cholesterol levels increased significantly in Groups 0, I, and II; triglyceride levels increased in Groups 0 and I. HDL cholesterol decrease was more in Groups 0 and I. In women, mean levels of total cholesterol, LDL cholesterol and triglycerides increased significantly in Group 0 and HDL cholesterol decreased in Group I (Figure 3). The 474 JAPI VOL. 51 MAY 2003

6 Fig. 2 : Prevalence of coronary risk factors in different educational groups in the first and the second study. Educational Group 0 is denoted by dark bars, and successive bars represent Groups I, II and III respectively. The first study shows significant trends calculated using least-squares regression analysis in obesity (men). In the second study significant trends are observed in smoking (men), leisure-time physical inactivity, obesity (men), and truncal obesity (men). This suggests that smoking and physical inactivity are increasing in illiterate men, while obesity and truncal obesity are increasing among more literate. magnitude of increase in levels of total cholesterol, LDL cholesterol and triglycerides was the largest in illiterate persons. DISCUSSION This study shows a significant increase in coronary risk factors in an urban Indian population over a seven-year period. There is increase in diabetes, obesity, high total and LDL cholesterol and low HDL cholesterol in both men and women. Low socioeconomic status individuals, characterized by illiteracy and low educational level, demonstrate increased prevalence of smoking, sedentary lifestyle, diabetes and abnormal lipid profile. The increase in coronary risk factors in this urban Indian population correlates well with the increasing coronary heart disease in India and other developing countries. 1 In the present study we failed to demonstrate any overall change in the coronary heart disease prevalence as compared to the earlier study. 14 This could be due to the fact that the present study lacked sufficient statistical power. The increase in multiple coronary risk factors is similar to a recent study from China and other developing countries. Yu et al, 5 in China, reported a 3% increase in smoking in men, 4% (men) and 3% (women) increase in hypertension, and significant increase in diastolic blood pressure among 14,275 Tianjin residents over a seven-year period. In the Yugoslavian cohorts of the Seven Countries Study the prevalence of smoking, hypertension and physical inactivity as well as population cholesterol levels increased over a 15-year period. 16 Rural-urban migrant studies in India and Africa showed increase in obesity, hypertension and cholesterol levels among the migrant subjects. 6 These results are similar to the present study. On the other hand, in Mauritius, where a community-wide cardiovascular disease prevention was evaluated, Dowse et al 4 reported a decline in prevalence of smoking, hypertension and physical inactivity over a fiveyear period, the prevalence of overweight/obesity increased and no change was observed in population cholesterol levels. In India, no non-communicable disease prevention program has been initiated hence our results are not comparable. Age-adjusted smoking prevalence has not changed significantly in men and has declined in women. However, smoking has increased significantly in the illiterate and loweducational status men and women. This suggests the target population for smoking intervention programs should be the illiterate. Public awareness programs appear to be successful in declining smoking trends among the more literate subjects. The large increase in diabetes prevalence may be an artifact JAPI VOL. 51 MAY

7 Fig. 3 : Mean blood lipid fractions in men and women in the first (1995) and the second (2002) study. The dark bar denotes Group 0 and successive bars are Groups I, II and III. In the first study with increasing education there is a weak increasing trend in mean levels in men of total cholesterol (CHOL), LDL cholesterol and TG (triglycerides), while in the second study in men there is a significantly decreasing trend with in total cholesterol, LDL and triglyceride levels. In women, in both the studies with increasing education there is decreasing trend in total cholesterol, LDL and triglyceride levels and the trend in more significant in the second study. but also could be due to increased awareness as self-reported diabetes prevalence has increased significantly in illiterate and low educational classes. In the second study, we diagnosed diabetes using the recent criteria of knowndiabetes or fasting hyperglycaemia and the prevalence of diabetes was 13.1% in men and 11.3% in women. The diabetes prevalence rates (Table 2) compare well with a recent Indian multi-centric study that reported diabetes in 8%-15% of general population in different parts of India and confirms diabetes epidemic in this part of the world. 17 The levels of blood pressure and prevalence of hypertension have not shown very large changes. However, the increase in standard deviations in the second study 29 denote increased population dispersion of blood pressure levels and correlates well with the increased prevalence of hypertension in men. It seems that the given period is very small to compare trends in hypertension prevalence. 18 A study from Chandigarh reported increase in hypertension ( 140/ 90) prevalence from 26.9% in 1968 to 44.9% in In the present study the increase in diabetes and hypertension prevalence in men could be due to the large increase in prevalence of overweight subjects (Table 2). Although we have not inquired regarding the dietary habits of these individuals (a study limitation), a recent study from Delhi has reported a high prevalence of obesity and truncal obesity associated with a diet rich in calories and saturated fats among the urban slum-dwellers. 12 The large increase in obesity in the present study can, therefore, be accounted for by the high calorie foods that are easily available to an urban Indian population. The substantial increase in lipid levels (Figure 1) over such a short-time period is alarming. This can be attributed to dietary factors involving larger intake of calories, saturated fats and cholesterol and low intake of monounsaturated fats and n-3 fatty acids as reported in our earlier 20 and other studies. 12 In the rural Japanese cohorts of Seven Countries Study cholesterol levels in men increased from 150 ± 41 mg/dl in 1958 to 161 ± 32 in1977, 178 ± 35 in 1982 and 188 ± 37 mg/dl in This was associated with an increased intake of meat and milk-products and decline in rice intake. In various Yugoslav cohorts of Seven Countries Study 16 the increase in cholesterol levels over a 15-year period was associated with increase in dietary fat consumption. At 5- yearly periodic examinations, in Velika Krsna the cholesterol levels increased from ± 31 mg/dl to ± 35 and ± 36; in Zrenjanin these increased from ± JAPI VOL. 51 MAY 2003

8 mg/dl to ± 39 and ± 46; and in Beograd cohort these increased from ± 41 mg/dl to ± 45 and ± 43; all associated with dietary changes and increasing body-mass index and systolic blood pressure. On the other hand, declining population cholesterol levels in the USA and other parts of Western Europe are ascribed to changes in dietary habits and increased physical activity levels. 3 More dietary epidemiological studies in India are needed to clarify the issues involved in the present study. The present study also shows a greater prevalence of certain coronary risk factors among the illiterate and less literate subjects belonging to low socioeconomic classes. Smoking, fasting hyperglycaemia, total cholesterol, LDL cholesterol and triglycerides are more and hypertension and obesity less among the lower social classes. These findings are similar to studies from North America and Western Europe. 7 In conclusion, the present study shows a significant increase in diet-related coronary risk factors- obesity, diabetes, hypertension and dyslipidaemias in an Indian urban population with smoking and dyslipidaemias increasing more in the low socioeconomic status individuals. The focus of prevention programs in India and other developing countries should be on decreasing coronary risks among the deprived of the society. REFERENCES 1. Reddy KS, Yusuf S. Emerging epidemic of cardiovascular disease in developing countries. Circulation 1998;97: Murray CJL, Lopez AD. Global mortality, disability, and the contribution of risk factors: Global Burden of Disease Study. Lancet 1997;349: Thom TJ. International mortality from heart disease: rates and trends. Int J Epidemiol 1989;18(Suppl 1):S20-S Dowse GK, Gareeboo H, Alberti KGMM, Zimmet P, Toumelhito J, Purran A, et al. Changes in population cholesterol concentrations and other cardiovascular risk factor levels after five years of the non-communicable disease intervention programme in Mauritius. BMJ 1995;311: Yu Z, Nissinen A, Vertiannen E, Song G, Guo A, Tian H. Changes in cardiovascular risk factors in different socioeconomic groups: seven year trends in a Chinese urban population. J Epidemiol Comm Health 2000;54: Gupta R, Rastogi S, Panwar RB, Soangra MR, Gupta VP, Gupta KD. Major coronary risk factors and coronary heart disease epidemic in India. South Asian J Prev Cardiol 2003;7: Kaplan GA, Keil JE. Socioeconomic factors and cardiovascular disease. A review of the literature. Circulation 1993; 88: Rozanski A, Blumenthal JA, Kaplan J. Impact of psychological factors on the pathogenesis of cardiovascular disease and implications for therapy. Circulation 1999;99: Sarvotham SG, Berry JN. Prevalence of coronary heart disease in an urban population in Northern India. Circulation 1968;37: Gupta R, Gupta VP, Ahluwalia NS. Educational status, coronary heart disease, and coronary risk factor prevalence in a rural population of India. BMJ 1994;309: Pais P, Pogue S, Gerstein H, Zachariah E, Savitha D., Jayaprakash S, Yusuf S. Risk factors for acute myocardial infarction in Indians: a case-control study. Lancet 1996;348: Misra A, Sharma R, Pandey RM, Khanna N. Adverse profile of dietary nutrients, anthropometry and lipids in urban slum dwellers of northern India. Eur J Clin Nutr 2001; 55: Rose GA, Blackburn H, Gillum RF, Prineas RJ. Cardiovascular Survey Methods. 2nd Ed. WHO Monograph Series No. 56. Geneva. World Health Organisation, Gupta R, Prakash H, Majumdar S, Sharma SC, Gupta VP. Prevalence of coronary heart disease and coronary risk factors in an urban population of Rajasthan. Indian Heart J 1995;47: Gupta R, Gupta VP, Sarna M, Bhatnagar S, Thanvi J, Sharma V, et al. Prevalence of coronary heart disease and risk factors in an urban Indian population: Jaipur Heart Watch-2. Indian Heart J 2002;54: Toshima H, Koga Y, Blackburn H (Editors). Recent trends in cardiovascular disease and risk factors. In: Lessons for Science from the Seven Countries Study. Tokyo. Springer-Verlag. 1994; Ramachandran A, Snehalatha C, Kapur A, Vijay V, Mohan V, Das AKet al. High prevalence of diabetes and impaired glucose tolerance in India: National Urban Diabetes Survey. Diabetologia 2001;44: Gupta R, Al-Odat NA, Gupta VP. Hypertension epidemiology in India: meta-analysis of fifty-year prevalence rates and blood pressure trends. J Human Hypertension 1996;10: Ahlawat SK, Singh MMC, Kumar R, Kumari S, Sharma BK. Time trends in the prevalence of hypertension and associated risk factors in Chandigarh. J Indian Med Assoc 2002;100: Singhal S, Gupta P, Mathur B, Banda S, Dandia R, Gupta R. Educational status and dietary fat and anti-oxidant intake in urban subjects. J Assoc Physicians India 1998;46: JAPI VOL. 51 MAY