ISSN- 0301-1216 Indian J. Prev. Soc. Med. Vol. 45 No. 1-2, 2014 A CORRELATIVE STUDY ON HYPERTENSION AND ANTHROPOMETRIC PARAMETERS IN RURAL POPULATION OF TEHRI GARHWAL Praveer Saxena 1, Daya Prakash 2 ABSTRACT Obesity adversely affects the normal human metabolic function and can lead to Hypertension, Coronary Heart Disease, Diabetes and other metabolic syndrome. This study was carried out to assess the association of four obesity-related indices body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to- Height ratio (WHtR). with hypertension. This study was carried out at Rural Health Training Centre (RHTC) Kirtinagar of VCSG Govt. Medical Science and Research Institute, Srinagar-Garhwal. A total 1241 rural inhabitant; 19 year and above were screened from Jan. 2011 to July 2011. Out of which 562 were male and 688 were female. With respect to Body Mass Index, Waist circumference, Waist-to-Hip ratio and Waist-to-Height ratio 15.4%, 7.24%, 13.94%, 12.0% were found obese respectively. Out of the four anthropometric variable waist circumference was most strongly associated with Hypertension (β=0.34, p 0.02) and then Body Mass Index ((β=0.32, p 0.02) and Waist- Hip ratio (β=0.23, p 0.045) was found associated. Key Words: Anthropometric variable, Hypertension, Rural-Hilly area. INTRODUCTION Obesity is now an important emerging Public Health Problem in India. Obesity is one of the major risk factor for hypertension. Obesity is also associated with decrease insulin sensitivity, diabetes, hypertension and dyslipidaemia, all of which are risk factors for coronary artery disease. Overweight persons have two- to six fold increase in the risk of developing hypertension. There is increase of 2-3 mmhg in systolic and 1-3 mmhg in diastolic blood pressure for every 10 kg increase in body-weight. 1 Body Mass Index (weight in kilograms divided by the square of the height in meters) is the most useful epidemiological marker of obesity but It is rather insensitive index to measure regional obesity i.e. abdominal obesity 2 Waisthip circumference ratio, waist-height ratio and waist circumference are important epidemiological tool to identify regional abdominal adiposity. 3 A study in urban population of India depicts strong relationship between different anthropometric indicators and blood pressure levels. 4 Little is known about these relationships in rural Indian population especially in Hilly Population. The present study was therefore undertaken to examine the relationship between different anthropometric indicators and blood pressure levels in rural population of Tehri-Garhwal district in Uttarakhand. MATERIAL AND METHODS This Hospital based study was carried out at Rural Health Training Centre (RHTC) Kirtinagar of Department of Community Medicine, VCSG Govt. Medical Science and Research Institute 1. Associate Professor, Deptt. of Community Medicine, Integral Institute of Medical Sciences and Research, Lucknow 2. Associate Professor, Deptt. of Community Medicine, Eras Medical College and Hospital, Lucknow Indexed in : Index Medicus (IMSEAR), INSDOC, NCI Current Content, Database of Alcohol and Drug Abuse, National Database in TB and Allied Diseases, IndMED, Entered in WHO CD ROM for South East Asia.
The required sample size was 1241 based on the prevalence of hypertension 7.24% as reported by Todkar et al in rural Maharashtra study with 10% non response error 5. Average new patient OPD load in RHTC is around 50.Due to limited manpower daily 10 subjects were interviewed. So every 5 th patient was included in a systematic random manner. Duration of study was from Jan. 2011 to July 2011. After obtaining oral consent, blood pressure was measured on left arm by auscultatory method using mercury sphygmomanometer (Diamond Co., Industrial Electronics and Allied Products, Electronics Cooperative Estate, Pune, Maharashtra). Hypertension was defined as systolic blood pressure (SBP) >140 mmhg and/or diastolic blood pressure (DBP) >90 mmhg or taking antihypertensive medications (6). An appropriate-sized cuff (cuff bladder encircling at least 80 percent of the arm above the elbow) given below was used (Table-1). Table- 1: Arm and corresponding Cuff Size in Sphygmo-manometer Arm Cuff Size 22 to 26 cm 12 x 22 cm 27 to 34 cm 16 x 30 cm 35 to 44 cm 16 x 36 cm Blood pressure was recorded after a person seated quietly for at least 15 minutes in a chair with feet on the floor, and arm supported at heart level. In addition, participants were advised to avoid exercise, alcohol, cigarette smoking and coffee/tea at least 30 minutes before BP measurement. The cuff was applied evenly to the upper arm and was rapidly inflated until the Manometer reading was 30 mm Hg. above the level at which Radial Pulse disappears, and then slowly deflated at the rate of 2 mmhg./sec. Two readings at five minute intervals as per the WHO guidelines were recorded. SBP was considered as a point at which the first sound is heard (phase 1), and DBP was considered as a point before the disappearance of sound (phase 5). Average of these two readings was used in the present analyses 6. Body weight was measured (to the nearest 0.5 kg) with the subject standing motionless on weighing scale. Each weighing scale was standardized every day with a weight of 50 kg. Height was measured (to the nearest 0.5 cm) with the subject standing in an erect position against a vertical scale of portable stadiometer and with the head positioned so that the top of the external auditory meatus was in level with the inferior margin of the bony orbit Waist circumference was measured at the level halfway between the iliac crest and the costal margin in the mid-axillary line after exhaling with the subject in standing position. Hip circumference was measured at the level of greater trochanters with the subject in standing position and both feet together.. BMI (Body Mass Index ) was calculated as weight in kilograms divided by squared height in meter. BMI was calculated by the standard formula and based on their BMI, individuals were classified into three groups: Low (BMI <18.5), Normal (BMI = 18.5-22.99Kg/m 2 ), Overweight (23.00-24.99 Kg/m 2 ) and Obese (BMI >25Kg/m 2 ) as per WHO s classification. Male subjects having Waist circumference (WC) more than 102cmr and female subjects having waist circumference more than 88c.mr.were considered as obese. Males having waist-hip ratio more than 0.9 and females having waist-hip ratio more than 0.8 was considered overweight. Males and Females having waist-height ratio more than 0.5 was considered overweight. WHtR is an important index of central obesity, which is free from any bias due to hip width changes along with waist circumference of short and tall subjects. 7 Data were analyzed using SPSS 10.0. T-test is used to compare difference between two mean. For dichotomous variable biserial correlation coefficient is used. Multiple logistic regression analysis was used to assess the influence of different anthropometric indicators on the SBP and DBP. All tests of significance were two tailed and level of significance was taken at P<0.05. 36
RESULTS Patients attending the OPD of Rural Health Training Centre were included in this study. Total 1250 persons of 19 year and above were screened. Out of which 562 were male and 688 were female (Table-2). In male the prevalence of hypertension was 23.1% and in female the prevalence of hypertension was 19.3%. The overall prevalence of hypertension was 21.3%. The mean systolic blood pressure in male was 124.34±23.56 mmhg and in female it was 120.89±22.45 mmhg. The mean Diastolic blood pressure in male was 81.32±13.78 mmhg and in female it was 79.54 ±12.50 mmhg. The difference between mean Systolic blood pressure (t =2.64 & mean, p =0.0083) Diastolic blood pressure (t = 2.39, p = 0.02) was found statistically significant. The prevalence of overweight and obesity defined as BMI >23.0 and >25.0 was found to be 23.84 and 25.64 per cent respectively in males and 16.13 and 36.28 in female respectively. The mean age of male subjects was 31.4±8.4 and the mean age of female subjects was 30.6±14.3.The mean height of male and female subjects was 160.23±10.5 and 150.45±8.90 respectively. Table-2: Baseline characteristics of study population Characteristics Male Female Number 562 688 Number of hypertensives (%) 130 (23.1%) 135 (19.3%) Age (yr) 31.4±8.4 30.6±14.3 Height (cm) 160.23±10.5 150.45±8.90 Weight (kg) 46.2±13.50 39.4±14.56 Body mass index (kg/m2) 19.45±6.87 18.45±9.56 Waist-hip ratio 0.78±0.078 0.74±.092 Waist circumference (cm) 74.45±12.56 64.34±9.78 Waist-height ratio 0.41±0.046 0.40±0.43 Systolic blood pressure (mmhg) 124.34±23.56 120.89±22.45 Diastolic blood pressure (mmhg) 81.38±13.78 79.54±12.50 The mean BMI of male and female was19.45±6.87 and18.45±9.56 respectively. The mean waist hip ratio in male and female was 0.78±0.078 and 0.74±.092 respectively. The mean waist circumference ratio in male and female was 74.45±12.56 and 64.34±9.78 respectively. The mean waist height ratio in male and female was 0.41±0.046 and 0.40±0.43 respectively. 8.72 per cent males had waist circumference more than 102 cmr and 7.56 per cent females had higher waist circumference more than 88 c.mr, 23.32 per cent males and 17.69 percent females had WHR higher than the cut-off value (Table-3). Table-3: Prevalence of overweight/obesity as per different anthropometric indicators Anthropometric Indicators Male Female Body Mass Index (kg/m2) Waist-height ratio Waist (Male <94 cmr, 94-102 cmr >102 cmr; Female <80 cmr 80-88 cmr >88 cmr) Waist-hip circumference ratio (0.9 for males and 0.8 for females) 37 No % No. % <18.5 137 24.38 185 26.39 18.5-22.9 196 34.87 235 34.16 23-24.9 151 26.87 155 22.53 >25.0 78 13.88 113 16.42 <0.5 480 85.41 621 90.26 0.5 82 14.69 67 9.74 415 73.84 564 81.98 98 17.44 72 10.46 49 8.72 52 7.56 <Cut-off value 458 86.09 589 85.61 >Cut-off value 74 13.91 99 14.39
Mean values of body mass index, waist hip ratio, waist circumference and waist-height ratio was significantly higher among hypertensive than normotensive men and women (Table-4). Table-4: Comparison of anthropometric variables between hypertensive and normotensive subjects Male Female Total Normotensive Hypertensive Normotensive Hypertensive Normotensive Hypertensive 432 (69.91%) 130 (30.09%) 553 (80.38%) 135 (19.62%) 985 (78.80%) 265 (21.2%) Weight 51.87±12.42 59.4± 10.34 48.23±16.54 53.34±12.81 49.78±12.43 52.65±10.42 t = 6.29, p =0.0001 t =3.35, p =0.0008 t =3.45, p=0.0006 Height 159.4±9.43 160.2±8.86 153.58±6.52 154.4±5.42 156.79±2.1 157.45±3.47 t = 0.86, p =0.39 t =1.35, p =0.177 t =1.01,p=0.22 BMI 19.75±2.90 21.34±5.73 18.84±4.34 21.41±3.85 19.43±2.8 21.23±3.1 Waist Waist Hip ratio Waist Height ratio t =4.24, p =0.0001 t =6.30, p =0.0001 t =9.07, p =0.0001 68.22±11.49 76.45±16.43 60.67±15.95 68.43±14.58 64.90±14.27 74.34±11.58 t =6.43, p =0.0001 t =5.15, p =0.0001 t =6.30, p =0.0001 0.71±0.04 0.79±0.062 0.65±0.026 0.72±0.084 0.68±0.04 0.75±0.03 t =17.38, p =0.0001 t =16.63, p =.0001 t =9.43, p=.0001 0.42±0.054 0.46±0.043 0.41±0.065 0.48±0.040 0.47±0.034 0.42±0.021 t =7.74, p =0.0001 t =11.97, p =.0001 t =9.43, p=.0001 P value <0.05 is significant It can be seen (Table-5) as the BMI is increasing prevalence of hypertension is also increasing.in male 21.93% of normal subjects (BMI =18.5-22.9) was found hypertensive whereas 23.84% of overweight subjects (23-24.99kg/mr 2 ) and 25.64% of obese subjects (BMI>25kg/mr 2 ) was found hypertensive. In female with normal range of BMI (18.5 22.9 kg/mr 2 ) 20.42% subjects were found hypertensive whereas 16.13% of overweight subjects and 36.28% of obese subjects was found hypertensive. In total study population subjects belong to underweight category BMI <18.5, the prevalence of hypertension was found 16.15%. Individual belong to normal category BMI=18.5-22.99, the prevalence of hypertension was found 21.11%.Individual belong to overweight category 23.00-24.99 the prevalence of hypertension was found 19.93%. Individual belong to obese category BMI >24.99 the prevalence of hypertensionwasfound31.93%.this difference was found statistically significant (p value<0.00). BMI Kg/mr 2 Table-5: Hypertensive status in relation to BMI Male Female Total Normotensive Hypertensive Normotensive Hypertensive Normotensive Hypertensive No. % No. % No. % No. % No. % No. % <18.5 106 71.38 31 22.62 164 88.65 21 11.35 270 80.70 52 16.15 18.5-22.9 153 72.55 43 21.93 187 79.58 48 20.42 340 79.07 91 21.11 23-24.9 115 72.33 36 23.84 130 83.87 25 16.13 245 78.03 61 19.93 >25.0 58 74.36 20 25.64 72 63.72 41 36.28 130 68.07 61 31.93 Total 432 76.87 130 23.13 553 80.38 135 19.62 985 78.80 265 21.20 2 =0.495,p=0.920 2 =29.2,p =0.00 P value <0.05 is significant 2 =18.4, p=0.000 38
It can be seen (Table- 6) as the waist circumference is increasing the prevalence of hypertension is also increasing in both sexes. In male with waist circumference >102 cmr 66.67% were found hypertensive as compare to male having waist circumference less than 94 cmr. Only 10.94% subjects found hypertensive. In female with waist circumference >88 cmr. 69.23% were found hypertensive as compare to female having waist circumference less than 80 cmr only 11.87% subjects found hypertensive. This difference is found statistically significant (p<0.05). Waist (cmr) Table-6: Hypertensive status in relation to waist circumference Male Waist Female No. % No. % (cmr) No. % No. % <94 364 89.06 51 10.94 <80 488 88.13 76 11.87 94-102 55 56.13 43 43.87 80-88 49 75.79 23 24.21 >102 13 33.33 36 66.67 >88 16 30.77 36 69.23 Total 432 76.87 130 23.13 Total 553 80.38 135 19.62 2 =12.1 p =0.000 2 =102, p =0.000 Anthropometric Indicator Table-7: Correlation between anthropometric indicators and hypertension Partial Correlation ( r ) Coefficient Male Female Total P Value* Partial Correlation ( r ) Coefficient P Value* Partial Correlation ( r ) Coefficient P Value Waist 0.51 0.000 0.35 0.000 0.41 0.00 BMI 0.44 0.000 0.26 0.041 0.32 0.035 Waist Height ratio 0.12 0.07 0.08 0.10 0.09 0.1 Waist Hip ratio 0.35 0.034 0.42 0.026 0.38 0.04 P value <0.05 is significant In males co-relational analysis shows maximum correlation of prevalence of hypertension with waist circumference (r= 0.51, p=0.000) followed by BMI (r=0.44, p<0.00) and waist-hip ratio (r=0.35, p<0.034).the waist height ratio is nonsignificantly correlated with prevalence of hypertension. In females co-relational analysis shows maximum correlation of prevalence of hypertension with waist circumference (r= 0.35, p=0.000) followed by BMI (r=0.26, p<0.041) and waist-hip ratio (r=0.42, p<0.026).the waist height ratio is non-significantly correlated with prevalence of hypertension (Table-7). Multiple regression analysis controlled for age and sex shows significant association of waist circumference (β=0.34, p=0.02), Waist Hip ratio ( β=0.23, p<0.045), and BMI (β=0.32, p=0.02), with prevalence of hypertension.waist Height ratio is not significantly associated with prevalence of hypertension (Table-8). Table-8: Effect of anthropometric correlates on prevalence of hypertension; multiple logistic regression analysis β(95% C.I. of β) P value* Waist 0.34 (0.21 0.45) 0.02 Waist Hip ratio 0.23(0.15 0.29) 0.045 BMI 0.32(0.19 0.38) 0.02 39
DISCUSSION In the present study, mean values of all the anthropometric indicators were significantly higher in hypertensive than in normotensive population in both the genders. These findings were similar to study carried by Midha et al in Lucknow district and Kokiwar et al in rural area of Karimnagar. 8,14 The mean BMI of hypertensives was found 21.23±3.1 kg/mr 2 as compared to non-hypertensives in whom mean BMI was found 19.43±2.8 kg/mr 2. Midha et al, Kokiwar et.al also reported that mean BMI of hypertensives was higher than the mean BMI of non-hypertensives. Present study has shown that subjects having BMI <18.5 kg/mr 2 16.15% were found hypertensive where subject having BMI >25 kg/mr 2 31.93% were found hypertensive similar result is shown by Midha et al, Todkar et al. 8,5 In males 21.93% of normal subjects (BMI =18.5-22.9) were found hypertensive whereas 23.84% of overweight subjects (23-24.99kg/mr 2 ) and 25.64% of obese subjects (BMI>25kg/mr 2 ) were found hypertensive. In female with normal range of BMI (18.5 22.9 kg/mr 2 ) 20.42% subjects were found hypertensive whereas 16.13% of overweight subjects and 36.28% of obese subjects were found hypertensive. Several studies have shown that Central obesity is positively correlated with hypertension 11,12,13,14. In present study the mean waist circumference of hypertensives was found 74.34±11.58 cmr which was significantly higher as compare to non hypertensives 64.90±14.27 c.mr. There was increasing prevalence of hypertension with increasing waist circumference. In females with waist circumference >88 cmr 69.23% were found hypertensive as compare to females having waist circumference less than 80 c.mr. only 11.87% subjects found hypertensive. Similar result were also depicted by Midha et al., Kokiwar et.al, Dhall et a 8,11,13. In Male Subjects having waist circumference <94 c.mr 10.94% were found hypertensive where subject having waist circumference >102 c.mr 66.67% were found hypertensive. Similar result were also shown by Midha et al, Snehalatha et al, Misra et al, Dhall et al 8,9,10,13. Multiple logistic regression analysis showed that waist circumference (β=0.34,p<0.05), waist-hip ratio (β=0.23, p <0.05)and BMI (β=0.32, p<0.05) were significantly associated with subject hypertensive status. Similar result were also shown by Midha et al and Kaur et al where BMI, Waist circumference were found significant 8,12. Results of partial correlation coefficients controlled for age and sex for all the anthropometric indicators BMI(r,0.44), WHR (r,0.35), WC (r,0.34) except waist-height ratio indicated significant positive correlation similar result were also shown by Ashwini et al in his study 14. CONCLUSION and RECOMMENDATION The classic Framingham study depicted that over 70% of hypertension among males and 61% among females was attributed to excess adiposity. Same phenomenon was also reciprocated in the intersalt study which also showed a strong association between body mass index and blood pressure. Obesity is the emerging public health problem even in hilly area also. This study finds the significant association of BMI, waist-hip ratio and waist circumference with respondent hypertensive status. This study recommends the population based health education programme to aware the community about health hazards due to obesity. They should also be informed about importance of early morning 40 mts. brisk walking, balanced diet and aerobic exercises. So that emergence of hypertension can be prevented. Acknowledgement: We thank, Mr. Mukesh Bhatt (P.S.W.), Mrs. Meena Kandari (Health Educator) in the Department of Community Medicine, VCSG Govt Medical Science and Research Institute, Srinagar-Garhwal, Uttarakhand. 40
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