|Year : 2016 | Volume
| Issue : 4 | Page : 292-298
BMI is a better indicator of cardiac risk factors, as against elevated blood pressure in apparently healthy female adolescents and young adult students: Results from a cross-sectional study in Tripura
Department of Medical Laboratory Technology, Women’s Polytechnic, Hapania, Tripura, India
|Date of Submission||06-Apr-2015|
|Date of Acceptance||11-Jun-2016|
|Date of Web Publication||3-Nov-2016|
Department of Medical Laboratory Technology, Women’s Polytechnic, Hapania, Tripura (W)
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Anthropometric measures are used as indicators of elevated blood pressure, but reported to have variable sensitivity among populations. This study was undertaken to identify the better indicator of Cardiac-risk factors by statistical comparison of BMI, Waist circumference, and Waist to Height (WtHr) ratio in apparently healthy adolescents and young adult female students of Tripura. Materials and Methods: A cross-sectional study was conducted in a resource limited setup on 210 apparently healthy female adolescents and young adult students in Tripura. Mean (±SD) of all parameters were compared (ANOVA) to recognize significant independent (anthropometric measures) and dependent factors (blood pressure indices and so on). Correlation (r) analysis was used to identify the better (p) indicator of blood pressure indices (dependent variable) and its impact was assessed by Multiple Regression analysis. Results: blood pressure indices are comparatively higher in obese and overweight participants with statistically significant (95.5% confidence) mean differences. Significant correlation with dependent factors is observed with BMI followed by WtHr and Waist Circumference. Impact of anthropometric measures with blood pressure Indices is most significant for BMI (P ≤ 0.020) followed by WtHr (P ≤ 0.500) and waist circumference (P ≤ 0.520). Conclusion: BMI is a superior indicator of blood pressure indices and can identify participants at risk even in apparently healthy adolescent and young adult females.
Keywords: Adolescent,young adults,female,Tripura,anthropometric measures,BMI,waist circumference,waist to height ratio, blood pressure indices, DBP, SBP, pulse pressure, mean pressure, rate pressure product, heart rate, students
|How to cite this article:|
Debnath S. BMI is a better indicator of cardiac risk factors, as against elevated blood pressure in apparently healthy female adolescents and young adult students: Results from a cross-sectional study in Tripura. Indian J Community Med 2016;41:292-8
|How to cite this URL:|
Debnath S. BMI is a better indicator of cardiac risk factors, as against elevated blood pressure in apparently healthy female adolescents and young adult students: Results from a cross-sectional study in Tripura. Indian J Community Med [serial online] 2016 [cited 2017 Mar 23];41:292-8. Available from: http://www.ijcm.org.in/text.asp?2016/41/4/292/193340
| Introduction|| |
Suboptimal blood pressure (>115 mmHg SBP) is the number one attributable risk for death throughout the world. Guidelines of advisory bodies (National Heart, Lung, and Blood Institute NHLBI, WHO) emphasize to increase awareness, prevention, and control of risk factors because awareness and early diagnosis of the vulnerability of hypertension and prehypertension can substantially reduce the risk .Anthropometric measures can be used as predictor for cardiovascular risk factors,, and essentially aids in prevention and control. However, there seems to have considerable variability of sensitivity among the anthropometric measures such as BMI, waist circumference, waist to height ratio and so on to predict cardiovascular risks among populations across geographies, ethnicity, and demography. The debate over a more sensitive anthropometric predictor of cardiovascular risks is amplified on the basis of the reports demonstrating variability in the efficacy of anthropometric parameters in predicting cardiovascular risks. According to several workers in India and abroad BMI alone is less accurate as a predictor and waist circumference and/or waist to height ratio is advocated as more sensitive indicator/s of cardiovascular risks,.On the contrary, some researchers argue that sensitivity of BMI is better and it sufficiently correlates with cardiovascular risk factors as hypertension., Yet another group reports BMI and waist circumference both are equally good predictors of cardiovascular risks., In this background, a study to evaluate sensitivity of anthropometric measures on cardiovascular risk factor as high blood pressure seems imperative, more so when similar studies are not reported from this region (Tripura).
In the present work, the focus is on correlation and the degree of association of anthropometric measures with blood pressure indices in apparently healthy female adolescent and young adult students. There was a general perception that women to be less vulnerable to cardiovascular complications but it is acknowledged that women are more prone to several other impediments for their inherent physiology,,,, which may have a negative synergistic effect if hypertension or prehypertension coexists. Moreover, prognosis of cardiac complications in women may be less satisfactory. Also in menopause the so-called "female advantage" is reversed due to rapid decrease in female steroid hormones, and thus, sex-associated differences must be considered in hypertension management of women., So identification of cardiovascular risk factors and its more sensitive anthropometric indicator even in apparently healthy female population is crucial for prevention and control of cardiovascular causalities in the long run. In this respect the present study is significant.
| Materials and Methods|| |
A cross-sectional study on anthropometric measures, blood pressure indices, and some hematologic parameters was conducted among the female students (Women’s Polytechnic) in Tripura, as a part of the academic dissertation during July 2014 and February 2015. All measurements were taken in duplicate and averaged.
Total 210 (n) female students of Women’s polytechnic studying in various disciplines in the age group 16–22 years participated in the study. Written consent of the participants and guardians were taken based on recommendation of World Medical Association Declaration of Helsinki Sixth revision guidelines. None of the participants were habitual users of Tobacco in any form. Any participant with immediate family history of sever cardiac anomalies were excluded from the study. All the included participants were on regular normal diet .All these factors including age, demography (urban/rural), ethnicity (data not shown), and medical history were self-reported by the participants. Participants on any medication and with any significant medical history were excluded from the study.
Trained female students of the institute carried out all measurements during college hours. Body weight (kg), height (m), waist circumference (cm) of the participants were collected in college uniform and subsequently adjusted. Measures were taken in relaxed standing position without shoes. Weight was measured in a doctor’s weight measuring machine (Krup’s) and Height was measured by a standard measuring tape against a wall. Waist circumference (cm) was measured at the midpoint between the lower costal margin and the top of iliac crest, while the participant was in the standing position using a non-stretch tape (WHO ).
Blood Pressure Indices
SBP and DBP (first and fifth Korotkoff sounds, respectively, using Stethoscope, Microtone) were measured to the nearest even digit by auscultation with an appropriate-size cuff and an aneroid sphygmomanometer (Diamond, ISI 3390). Blood pressure measurements were made in nonfasting state in the seated position. Heart rates (HR Times/minute) were measured manually using stop watch (Samsung).
Hemoglobin concentration (gm/dl) were detected by Sahli’s method (Marienfeld–Hemoglobinometer) using 0.1N HCl (Merck). Sahli’s method is a efficacious method of hemoglobin estimation in the field work, and is significantly economical in resource limited set up like in this case. RBC surface antigens were detected (ABO blood typing kit – Tulip Diagnostics) in the participants for database purpose and Rh typing was not done.
| Statistical analysis|| |
Data are expressed as mean, standard deviation, and range (max-min). Mean differences of parameters among the BMI classes are reported with statistical significance for dependent variables (ANOVA). Correlation (r) analysis was used to identify the better (p) indicator of elevated blood pressure (dependent variable) in the studied population and its impact was assessed by Multiple Regression analysis of parameters. Origin and MS Excel statistical packages were used for the analysis.
Definitions of variables
BMI was calculated from weight (kg) and height (m) in kg/m2. It was such that the participants could be divided in total seven groups depending upon their BMI class. Normal (BMI 18.5–24.9 kg/m2), overweight (25–30 kg/ m2), obese clas6s I (30–35 kg/m2), obese class II (35–40 kg/m2), severe thinness (<16 kg/m2), moderate thinness (16–17 kg/m2) and mild thinness (17–18.5 kg/m2).Waist to height ratio (WtHr) is a simple ratio. Among Cardiac parameters Pulse pressure (PP) was determined as the difference between SBP and DBP. Mean Pressure was calculated as DP + 1/3 PP, whereas Rate Pressure Product (RPP) was calculated as SP × HR × 10–2.
| Results|| |
The sample population (n = 210) could be categorized into seven BMI categories. Anthropometric measures and hemoglobin (g/dl) of the population with sample size (n) is depicted in [Table 1]. Age and demography (urban/rural) is depicted in [Table 3]. It is apparent that mean age of obese (class I/II) and severe thin participants are higher compared with other BMI categories, as well as from the overall population. Blood pressure indices and HR is depicted in [Table 2] and [Table 4]. SBP, DBP, and mean pressure is comparatively higher in obese (I/II) and overweight participants with statistically significant (95.5% confidence) mean differences. BMI is positively correlated to DBP [r (+) 0.252185854, P = 0.0001], mean pressure [r (+) 0.248430338, P = 0.0002] and SBP [r (+) 0.203482052, P = 0.001] [Table 5]. BMI is also positively correlated to RPP and hemoglobin level but the correlation is not significant. Waist circumference is positively correlated with SBP, DBP, mean pressure, RPP, and hemoglobin level; however, significant correlation is found with DBP (r = (+) 0.227278779, P = 0.0006) and mean pressure (r = (+) 0.200640562, P = 0.001). WtHr is also positively correlated with SBP, DBP, mean pressure, RPP, and hemoglobin level and is significantly correlated with DBP (r = (+) 0.217848832, P = 0.0007) and mean pressure (r = (+) 0.189695053, P = 0.002). HR and PP are negatively correlated to BMI, waist circumference, and WtHr but the relationship is not statistically significant. Direct impact of independent variables (BMI, waist circumference, and WtHr) on the dependent variables (SBP, DBP, and mean pressure), which have significant correlation are depicted in [Table 6]. Impact of anthropometric measures with blood pressure indices is most significant for BMI (P ≤ 0.020) followed by WtHr (P ≤ 0.500) and waist circumference ( P ≤ 0.520) in the population.74.88% of the population are from urban Tripura and among RBC antigens “O” (30.80%) is the most common in the population followed by “A” (25.23%) , “B” (24.64%), and “AB” (18.95%).
|Table 1: Mean (±SD) of BMI , waist circumference , waist to height, and hemoglobin level in the population|
Click here to view
|Table 2: Mean (±SD) of SBP, DBP, pulse pressure, heart rate in the population|
Click here to view
|Table 5: Correlation analysis among Dependent and Independent parametrs in the population|
Click here to view
|Table 6: Multiple regression analysis among the significantly correlating dependent and Independent parameters in the population|
Click here to view
| Discussion|| |
The present study was conducted among 210 female adolescent and young adult students of Tripura to analyze the fidelity of using BMI as an indicator of suboptimal blood pressure in apparently healthy females. The schematic representation of the decision pathway is illustrated in Figure 1. Analysis of mean of parameters helped to initially identify significant independent (anthropometric measures) and dependent factors (Blood pressure indices, HR, and so on). Significance of correlation was used to pinpoint the most sensitive anthropometric index and the regression analysis fortified the argument. Overweight and Obese (I/II) participants (according to BMI categories) have WtHr more than 0.50 , the cutoff value for all age groups. SBP, DBP, and mean pressure is comparatively higher in obese (I/II) and overweight participants (95.5% confidence). When anthropometric parameters were correlated to Blood pressure indices, HR, and so on, it was observed that DBP and mean pressure are positively correlated to anthropometric measures to a significant extant followed by SBP. Therefore, DBP seems to be better responder in correlating anthropometric measures with blood pressure indices in the studied population. DBP is an important parameter that dictates cardiovascular outcome and is related to physiological stress and causality due to cardiac failure. Its significance in prevention and management of cardiovascular complications is established by the fact that a small reduction of 2 mmHg in DBP in the mean of the population distribution could have a great public health impact on the number of CHD and stroke events prevented. It is observed that PP, as well as, HR negatively correlates to anthropometric measures in the studied population. PP is a reliable indicator of vascular distensibility, whereas HR is an indicator of sympathovagal regulation. The negative correlation (anthropometric measures and PP/HR), although insignificant but can be explained on the basis of autonomic function and or energy metabolism in women with the aid of female steroid hormones., On the contrary, BMI among independent parameters is significantly correlated to most of the dependent factors (blood pressure indices and so on) than that of WtHr and waist circumference and the direct impact of BMI on the Blood Pressure indices are also more significant statistically.
Although it is observed that the Blood Pressure indices in the studied population is not alarming but normal BP in higher margin and hypertensive BP is regarded as a cause of concern in women. In the studied population 20% of the participants are either overweight or obese and have risk of developing cardiovascular complications. Individuals with prehypertensive levels of blood pressure have an increased risk of developing cardiovascular disease relative to those with optimal levels and the association is pronounced among those with high BMI. Also, high-normal blood pressure is associated with an increased risk of cardiovascular disease. Therefore, this study is significant and aids to identify participants at risks. In the studied population, it is observed that BMI is significantly associated with blood pressure indices and, therefore, is a good indicator of cardiovascular risks. It has been observed that the long-term reproducibility of BMI is superior and it significantly correlates to hypertension and prehypertension in various age groups even in normal individuals., Therefore, BMI is a superior predictor of cardiovascular risks in apparently healthy adolescent and young adult female students of Tripura.
|Figure 1: Schematic representation of the decision pathway (ORIGINAL FIGURE)|
Click here to view
| Limitations|| |
The participants included in this academic study were the students of Women’s Polytechnic , Govt. of Tripura. About 20% populations is overweight/obese and another 20% population is thin. Stroke volume was not estimated to indicate vascular distensibility. Demographical considerations were not addressed in analysis.
| Conclusion and Recommendation|| |
BMI is a superior indicator of blood pressure indices and can identify participants at risk of cardiovascular complications even in apparently healthy adolescent and young adult females. Screening on the basis of BMI may aid to awareness generation and prevention of complications. Identified participants were informed about the risk factors accordingly.
The corresponding author acknowledges Women’s Polytechnic, Govt. of Tripura for providing the infrastructure to conduct the study. The anthropometric data used in the cross-sectional study were collected by 6th semester (2015) DMLT students (Chandika Saha, Ankita Das, Bidhatri Sarkar Rajsmita Das, Sandipa Dhar) of Women’s Polytechnic, Govt. of Tripura.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
World Health Organization.The world health report 2002: reducing risks, promoting healthy life. World Health Organization, 2002.
Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr., Jones DW, Materson BJ, Oparil S, Wright JT, Jr. Roccella EJ. National High Blood Pressure Education Program Coordinating Committee. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. Hypertension
World Health Organization. Obesity: preventing and managing the global epidemic. World Health Organization; 2000.
National Institutes of HealthClinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults—the evidence report. Obes Res 1998;6:51-209S.
Emerging Risk Factors Collaboration.Separate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies. The Lancet. 2011;377:1085-95.
Panjikkaran ST, Kumari KS, Augmenting BMI and waist-height ratio for establishing more efficient obesity percentiles among school-going children. Indian Journal of Community Medicine. 2009;34:135.
Savva SC, Tornaritis M, Savva ME, Kourides Y, Panagi A, Silikiotou N, Georgiou C, Kafatos A. Waist circumference and waist-to-height ratio are better predictors of cardiovascular disease risk factors in children than body mass index. International journal of obesity 2000;24:1453-8.
Browning Lucy M, Hsieh Shiun Dong, Ashwell. Margaret, A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0·5 could be a suitable global boundary value. Nutr Res Rev 2010;23:247-69.
Falkner Bonita, Gidding Samuel S, Ramirez-Garnica Gabriela, Wiltrout Stacey Armatti, West David, Rappaport Elizabeth B, The relationship of body mass index and blood pressure in primary care pediatric patients. J Pediatr 2006;148:195-200.
Lorenzo C, Serrano-Rios M, Martinez-Larrad MT, Gabriel R, Williams K, Gonzalez-Villalpando C, Stern MP, Hazuda HP, Haffner S. Prevalence of hypertension in Hispanic and non-Hispanic white populations. Hypertension 2002.39:203-8.
Lee S, Bacha F, Arslanian SA, Waist circumference, blood pressure and lipid components of the metabolic syndrome. J Pediatr 2006;149:809-16.
Kaur S, Sachdev HP, Dwivedi SN, Lakshmi R, Kapil U, Sareen N, Association of obesity with hypertension amongst school-age children belonging to lower income group and middle income group in national capital territory of Delhi. Indian Journal of Community Medicine 2013;38:175.
Garg C, Khan SA, Ansari SH, Garg M, Prevalence of obesity in Indian women. Obes Rev 2010;11:105-8.
Lin TM, Chen KP, MacMohan B, Epidemiological characteristics of cancer of the breast in Taiwan. Cancer 1971;27:1497-504.
Li CI, Malone KE, White E, Daling JR, Age when maximum height is reached as a risk factor for breast cancer among young U.S. women. Epidemiology 1997;8:559-65.
Singh P, Kapil U, Shukla NK, Deo SV, Dwivedi SN. Association of overweight and obesity with breast cancer in India. Indian Journal of Community Medicine 2011;36:259.
Cabrerizo-García JL, Pérez-Calvo JI, Zalba-Etayo B, Influence of gender on prognosis of acute coronary syndromes. Rev Port Cardiol 2015;34:43-50.
BÄƒlan H, Popescu L, Gender specific medicine”: a focus on gender-differences in hypertension. Rom J Intern Med 2014;52:129-41.
Harvey RE, Coffman KE, Miller VM, Women-specific factors to consider in risk, diagnosis and treatment of cardiovascular disease. Womens Health (Lond Engl) 2015;11:239-57.
Schmidt H, Mehring S, McMillan J, Interpreting the declaration of Helsinki 2008: “Must”, “should” and different kinds of obligation. Med Law 2010;29:565-91.
World Health OrganizationPhysical status: the use and interpretation of anthropometry-Geneva: WHO Technical Report Series-854. 1995.
Anand Hema, Mir Rashid, Saxena Renu, Hemoglobin color scale a diagnostic dilemma. Indian J Pathol Microbiol 2009;52.
Kaplan NM. Measurement of blood pressure. Clinical hypertension 2002;19-40.
McCarthy HD, Ashwell M, Trends in waist: height ratios in British children aged 11-16 years over a two-decade period. In Proc Nutr Soc Am 2003;62:46A-46A. 1999.
Schnall PL, Pieper C, Schwartz JE, Karasek RA, Schlussel Y, Devereux RB, Ganau A, Alderman M, Warren K, Pickering TG. The relationship between'job strain,'workplace diastolic blood pressure, and left ventricular mass index: results of a case-control study. Jama 1990;263:1929-35.
Prospective Studies CollaborationCholesterol, diastolic blood pressure, and stroke: 13 000 strokes in 450 000 people in 45 prospective cohorts. Lancet 1995;346:1647-1653.
Cook Nancy R, ScDCohen Jerome, MDHebert Patricia R, PhDTaylor James O, MDHennekens Charles H, MDImplications of small reductions in diastolic blood pressure for primary prevention. Arch Intern Med 1995;155:701-709.
Wykretowicz A, Adamska K, Guzik P, Krauze T, Wysocki H, Indices of vascular stiffness and wave reflection in relation to body mass index or body fat in healthy subjects. Clin Exp Pharmacol Physiol 2007;34:1005-9.
Malliani A, Pagani M, Lombardi F. Methods for assessment of sympatho-vagal balance: power spectral analysis. Vagal control of the heart: Experimental basis and clinical implications 1994;7:433-54.
Shaikh WA, Patel M, Singh SK. Association of adiposity with pulse pressure amongst Gujarati Indian adolescents. Indian journal of community medicine: official publication of Indian Association of Preventive & Social Medicine. 2010;35:406.
Ravisankar P, Udupa KA, Prakash ES. Correlation between body mass index and blood pressure indices, handgrip strength and handgrip endurance in underweight, normal weight and overweight adolescents. Indian journal of physiology and pharmacology 2005;49:455.
Kshirsagar Abhijit V, Carpenter Myra, Heejung Bang, Wyatt Sharon B, Colindres Romulo E, Blood pressure usually considered normal is associated with an elevated risk of cardiovascular disease. Am J Med 2006;119:133-141.
Vasan Ramachandran S., Larson Martin G, Leip Erick P, Evans Jane C, Odonell Christopher J, Kannel William B, Levy Daniel, N Engl J Med 2001:345.
Gupta Anu Taneja, Siddhu Anupa, Desirable Factors for Maintaining Normal BMI of Urban Affluent Women of Delhi. Indian J Public Health 2015;59.
Kumar J, Deshmukh PR, Garg BS, Prevalence and correlates of sustained hypertension in adolescents of rural Wardha, central India. Indian J Pediatr 2012;79:1206-12.
Qing He, Ding Zong Yi, Fong Daniel Yee-Tak, Karlberg Johan, Blood pressure is associated with body mass index in both normal and obese children. Hypertension 2000;36:165-70.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]