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Prevalence of Elevated Blood Pressure Levels In PREVALENCE OF ELEVATED BLOOD PRESSURE LEVELS IN OVERWEIGHT AND OBESE YOUNG POPULATION (2 – 19 YEARS) IN THE UNITED STATES BETWEEN 2011 AND 2012 By: Lawrence O. Agyekum A Dissertation Submitted to Faculty of the School of Health Related Professions, Rutgers, The State University of New Jersey in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Biomedical Informatics Department of Health Informatics Spring 2015 © 2015 Lawrence Agyekum All Rights Reserved Final Dissertation Approval Form PREVALENCE OF ELEVATED BLOOD PRESSURE LEVELS IN OVERWEIGHT AND OBESE YOUNG POPULATION (2 – 19 YEARS) IN THE UNITED STATES BETWEEN 2011 AND 2012 BY Lawrence O. Agyekum Dissertation Committee: Syed Haque, Ph.D., Committee Chair Frederick Coffman Ph.D., Committee Member Shankar Srinivasan, Ph.D., Member Approved by the Dissertation Committee: _____________________________________ Date: _______________ _____________________________________ Date: _______________ ____________________________________ Date: _______________ ii ABSTRACT Prevalence of Elevated Blood Pressure Levels in Overweight and Obese Young Population (2 -19 Years) in the United States between 2011-2012 By Lawrence Ofori Agyekum Several studies have reported hypertension prevalence in children and adolescents in the United States (US) using regional or local population-based samples but few have reported national prevalence. The present study estimates national hypertension prevalence in US children and adolescents for 2011-2012. A convenient sample size of 4,196 (population aged ≤ 19) representing 43% of 9,756 (total survey respondents) was selected and stratified by age groups; “Children” and “Adolescents” using the 2007 Joint National Committee recommended definitions. Next, hypertension distribution was explained by gender, race, age, body weight, standing height and blood serum total cholesterol. Variations in BP levels were measured and expressed in percentiles for nominal variables and by means and standard deviations for continuous variables. Estimated national hypertension prevalence in the US for the 2011-2012 analysis period were 3% in children aged (2<=11 years) and 14% in adolescents aged (12<=19 years). Rates were highest among adolescent boys (4%) stage 1 and (7%) stage 2 and lowest among adolescent girls (2%) stage 1 and (0.86%) stage 2. Adolescent Blacks had highest relative rate (21% SE <1) compared to lowest rate of 8% in Non-Hispanic Asians. The highest BP risk factor was body weight with a t-value of 7.75 and (p<.0001). 05 significance. In conclusion, 4 of 10 (46%) US adolescents who had hypertension were either overweight or obese. The findings in this report suggest that overweight and obese children and adolescents might have increased risk of hypertension. Therefore, iii interventions that decrease obesity in children such as healthy eating and good exercise and those that decrease elevated BP levels in children and adolescents must be broad based and focused on children and adolescents at the risk of high BP. The major limitation of this study is that regression models used in this study assume constant variability across subpopulations and constant time between analysis periods. Therefore, interpretation of estimates from this study must be made only after a careful consideration of the methods used. The results confirm hypertension risk in children with associated prevalence of obesity. Therefore, comprehensive hypertension intervention programs can positively improve population health. Future studies should focus on assessing the impact of intervention programs. Keywords: Pediatric hypertension, hypertension and obesity, hypertension prevalence in children, hypertension definition in children, blood pressure measurement in children, hypertension risk factors. iv ACKNOWLEDGEMENTS There are many people who contributed their time, shared their knowledge and experiences to make this work successful. I would like to thank Faculty of the Department of Health Informatics, Rutgers School of Health Related Professions for their support and encouragement. Especially, Drs. Syed Haque, Frederick Coffman and Shankar Srinivasan for their enormous help and counseling accorded me throughout this research process. Special thanks goes to Ms. Kim Gadsden-Knowles, Associate Science Director for the Division of Health Informatics, Centers for Disease Control and Prevention (CDC), for her invaluable technical guidance and patience during on-site supervision. This work would not have been successful without Drs. Haque and Srinivasan and Ms. Gadsden-Knowles’s expertise and meaningful contributions. I also want to thank Ms. Yvonne Rolley and all staff of the Department of Health Informatics for their enormous assistance in coordinating counseling sessions. This work is dedicated to my spouse Margie Enele and two sons Clifford and Michael Agyekum whose love and support strengthened me to go through tedious days and nights of extensive reading in conducting this research and preparing this report. v TABLE OF CONTENTS TOPIC PAGE ABSTRACT. ……………………………………………………………….. iii ACKNOWLEDGEMENTS. ………………………………………………. v TABLE OF CONTENTS. …………………………………………………. vi LIST OF FIGURES. ………………………………………………………. x LIST OF TABLES. ………………………………………………………... xii LIST OF EQUATIONS................................................................................ xvi CHAPTER 1 INTRODUCTION 1.1 Statement of the problem. ………………………………………..... 1 1.2 Historical Background. …………………………………………..... 2 1.3 Study Purpose, Goals and Objectives. …………………………….. 8 1.4 Study Hypothesis. …………………………………………............. 9 1.5 Study Significance. ……………………………………………....... 10 1.6 Related Theories. ………………………………………………….. 11 1.7 Intended Results............................................................................... 13 CHAPTER 2 LITERATURE REVIEW 2.1 Disease and Economic Burden of Blood Pressure. ……………….. 14 2.2 Surveillance Definitions for Hypertension Prevalence and Control in Adults........................................................................................... 15 2.3 Definition of Hypertension: Perspectives from the 2007 Joint National Commission (JNC 7) Release............................................ 17 vi 2.4 Hypertension Definition in Children................................................ 20 2.5 High Blood Pressure Symptoms in Children and Adolescents........ 21 2.6 Link between High Blood Pressure and Obesity in Children........... 23 2.7 High Blood Pressure from Childhood to Adulthood........................ 26 2.8 Blood Pressure Measurement in Children........................................ 27 CHAPTER 3 RESEARCH METHODOLOGY 3.1 Study Design..................................................................................... 30 3.2 Data Sources and Data Elements..................................................... 31 3.3 Data Collection................................................................................. 32 3.4 Study Population.............................................................................. 33 3.5 Selected Sample............................................................................... 33 3.6 Variable Selection and Categorization............................................. 34 3.7 Analytic Variables, Exposures and Outcomes of Interest................ 35 3.7.1 Resultant Variable............................................................................ 37 3.7.2 Exposure Variables........................................................................... 38 3.7.3 Covariates......................................................................................... 39 3.8 Data Organization and Cleaning....................................................... 39 3.9 Analysis of Data............................................................................... 41 3.9.1 Descriptive Statistics........................................................................ 42 • Checking of Frequency Distribution and Normality............ 42 • Percentiles............................................................................. 44 • Means.................................................................................... 45 • Proportions............................................................................ 49 vii 3.9.2 Variance Estimation and Significance Testing of Blood Pressure Risk Factors...................................................................................... 49 Logistic Regression.......................................................................... 51 Linear Model of Unbalanced ANOVA............................................ 53 3.10 Measurements and Definitions of Cardiovascular Risk Factors...... 59 3.10.1 Classification of Body Mass Index (BMI)....................................... 59 3.10.2 Classification of Blood Pressure Levels........................................... 60 3.10.3 Classification of Cholesterol Levels................................................. 61 CHAPTER 4 RESULTS 4.1 Prevalence of Elevated Blood Pressure Levels in Us Children and Adolescents by Gender / Sex............................................................ 62 4.2 Prevalence of Elevated Blood Pressure Levels in US Children and Adolescents by Race/ Ethnicity........................................................ 66 4.3 Prevalence of Elevated Blood Pressure Levels in US Children and Adolescents by Body Mass Index.................................................... 74 4.4 Prevalence of Elevated Blood Pressure Levels in US Children and Adolescents
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