The Impact of Nutrition and Physical Activity Variables in Early Cardiovascular Disease Prevention

Abstract

Cardiovascular disease continues to be one of the leading causes of death worldwide. While much is known about the prevalence and risk of cardiovascular disease in adults, less is known about these variables in youth populations. Therefore, data was taken from two recent studies (e.g., High School Youth Risk Behavior Survey and the National Health and Nutrition Examination Survey, 2009-2010) to determine the precise role of physical activity and nutritional variables in the prevalence of early warning signs for cardiovascular disease. Results from this study confirmed previous research, demonstrating that students reporting healthier eating behaviors and higher levels of physical activity experience significantly lower risk factors for cardiovascular disease. The information gained from this study may be beneficial for researchers and practitioners seeking support for earlier health promotion efforts to combat cardiovascular disease. 

Introduction 

Cardiovascular disease is one of the leading causes of death throughout the world and serves as a pertinent global health promotion need. While a range of pharmacological and medical interventions have been explored in the treatment and prevention of cardiovascular disease, less is known about the specific impacts of lifestyle factors, such as nutrition and physical activity. Additionally, little is known about the longitudinal impact of nutrition and physical activity health promotion for youth populations. Most public health professionals agree that cardiovascular disease prevention is an important factor, not just in saving lives, but also reducing national healthcare costs. Therefore, the purpose of this paper is to explore the specific impact of key physical activity and nutritional variables in the secondary prevention of cardiovascular disease for youth populations. Specifically, this paper will analyze the impact of data gathered from two comprehensive data sets regarding dietary behaviors, exercise habits, and cardiovascular disease risk. A more detailed description of this issue will first be provided, as well as the purpose and significance of the current study. A review of relevant literature is then included, highlighting key points and gaps in existing research. The research methodology is then explained, followed by a description of the data analysis. This report concludes with a summary and outline of key points. 

Description of the Issue

Cardiovascular disease pertains to a broad range of problems related to the heart and its accompanying blood vessels (Williams, et al., 2004). The causes for this condition vary significantly but are strongly connected to hereditary factors, nutrition, exercise habits, tobacco and alcohol use, and psychological and emotional stress (Lawlor, Smith, Patel, & Ebrahim, 2005). Cardiovascular disease continues to be the leading cause of death worldwide, although declining trends in this disease suggest that people are adopting healthier lifestyle habits (Kiran, Hutchings, Dhalla, Furlong, & Jacobson, 2010). Experts also suggest that increased mindfulness of contributing factors and improved lifestyle behaviors serve as primary contributors to reduced mortality percentages (Lawlor, et al., 2005). Persons of all ages and ethnic backgrounds are at risk of cardiovascular disease, although older people, men, and persons from higher socioeconomic backgrounds countries experience the greatest incidence rates (Sharma. Malarchar, Giles,  &Myers, 2004). Male face approximately a 50% likelihood of acquiring cardiovascular disease at some point in their lives, while females face nearly a 33% risk (Liu, Maniadakis, Gray, & Rayner, 2002).  Almost 90% of individuals who die from cardiovascular disease are over the age of 60 (Williams, et al., 2004). However, cardiovascular disease begins during youth, representing a critical period in which healthy lifestyle promotion is needed (Williams et al., 2004). 

Cardiovascular disease typically develops with the onset of atherosclerosis, or a stiffening of the arterial walls that ultimately leads to the prevention of blood and oxygen delivery throughout the circulatory system (Kiran, et al., 2010). Atherosclerosis is frequently related to the buildup of cholesterol in the arteries, which is often a result of diets high in cholesterol and fat, tobacco usage, stress, and poor physical activity habits (Kelly & Stanner, 2003). Atherosclerosis commonly begins during youth, with beginning signs and symptoms appearing prior to 10 years of age (Lawlor, et al., 2005). Due to the fact that nearly 33% of all persons die from circumstances connected to atherosclerosis, recognizing early risk factors in children and young adults is particularly important in the fight against this disease (Kiran, et al., 2010). Cardiovascular disease is also related to diabetes and obesity, which is accompanied by its own adverse health-related and economic drawbacks (Kelly & Stanner, 2003). 

Although there is a substantial indication that lifestyle interventions are successful in the prevention of cardiovascular disease, less is known about the longitudinal impact of specific variables (e.g., nutrition and physical activity) and their impact on youth populations (Labarthe & Dunbar, 2012). It seems likely that addressing the causes of cardiovascular disease earlier in life will likely reduce the incidence of this public health problem for generations (Labarthe & Dunbar, 2012). However, few reviews have systematically evaluated the long-term impact of these health promotion variables for cardiovascular disease in youth and the specific determinants of these interventions' success (Labarthe & Dunbar, 2012). 

Purpose of the Study

Based on the lack of research described above, the purpose of this study is to assess the impact of dietary and exercise-related factors involved in cardiovascular disease prevention for youth populations. Specifically, this study aims to determine the relationship between key nutritional and physical activity variables (e.g., cholesterol intake, sports participation) have in the longitudinal prevalence of cardiovascular disease. Drawing on a review of the two comprehensive databases, this study will attempt to provide a coherent and accurate depiction of current knowledge related to youth secondary cardiovascular disease prevention. 

Significance of the Study

As cardiovascular disease is among the leading causes of death in almost every nation, understanding how to most effectively prevent this disease from an early age may have the ability to not only save lives but also reduce national healthcare costs. The information gathered from this study will help researchers, public health professionals, and parents and guardians more effectively address key factors that influence the occurrence of cardiovascular disease. 

Data to be Used

Two datasets will be used in the current study. First, the High School Youth Risk Behavior Survey (Centers for Disease Control and Prevention, CDC, 2011) will be used to assess dietary and physical activity behaviors in high-school-aged youths within the United States. Additionally, the National Health and Nutrition Examination Survey, 2009-2010 (CDC, 2013) will be utilized to assess the prevalence of cardiovascular disease in youth populations. 

Literature Review

In the past decade years alone, more than 500,000 peer-reviewed studies have been conducted on the varying risk factors, causes, prevention and rehabilitation of different forms of cardiovascular disease. Strokes and heart attacks represent the two most pertinent cardiovascular risks to adult patients worldwide, although these episodes are substantially less frequent in youth populations (Smith et al., 2012). However, the risk of strokes and heart attacks remains relatively high due to the often-undetected cholesterol build-up that begins to occur during childhood and adolescence (Smith et al., 2012). The high rates of strokes and heart attacks in adult populations may also be due to the persistent gap that seems to exist between cardiovascular disease research and public health promotion (Trioci, Allen, Kramer, Califf, & Smith 2009). Despite considerable advancements in knowledge related to cardiovascular disease prevention, health promotions efforts have been relatively slow to adopt new information in many cases (Trioci et al., 2009).  While educational interventions have significantly raised public knowledge of the risk factors and causes of cardiovascular disease, the public has also been much slower to incorporate healthful lifestyle alternatives such as low-fat diets, increased exercise, smoking cessation and abstaining from, or reducing, alcohol intake.

Public health professionals and researchers (e.g., Bibbins-Domingo et al., 2010) have acquired a significant understanding of the causes and prevention of cardiovascular disease over the past 10 to 20 years. Improved public health promotion efforts have resulted in increased knowledge of the causes and results of cardiovascular disease, while rehabilitative interventions have become more needs-based and oriented to individuals' specific risk factors (Groeneveld, Proper, van der Beek, Hildenbrandt, & van Mechelen, 2010). However, the prevalence of cardiovascular disease remains high in the United States, as well as globally (Groeneveld et al., 2010). According to the World Health Organization (WHO, 2013), more than one in ten deaths worldwide are directly a result of various forms of cardiovascular disease. Additionally, cardiovascular disease is the number one cause of all deaths in Western, industrialized countries (WHO, 2013). Therefore, the WHO (2013) currently lists heart attack and stroke prevention as a top-five public health concern for public health professionals. 

The Centers for Disease Control and Prevention (CDC, 2013) has served as one of the global frontrunners in the prevention of cardiovascular disease, as well as the implementation of interventions to combat this health problem. This CDC's Division for Heart Disease and Stroke Prevention (DHDSP) made its first major attempt to explore the causes of these two cardiovascular diseases in the mid-1980s, with the development of its Behavioral Risk Factor Surveillance System. This public health effort was designed to gather blood pressure and cholesterol data from individuals around the country and develop a longitudinal database for cardiovascular disease risk factors. This national effort ultimately resulted in a substantial expansion of public knowledge related to cardiovascular disease prevention, as well as early warning signs for episodes such as strokes and heart attacks (CDC, 2013). Further work by the CDC to contest the high incidence of cardiovascular disease consist of the Cholesterol Education Program (CEP), development of the Cardiovascular Health (CVH) Practitioners Institute, partnering with the WHO to develop a worldwide stroke and heart attack database, and creation of the National Acute Stroke Registry. All of these efforts have helped in the ongoing battle against the multiple variations of cardiovascular disease (CDC, 2013). Nevertheless, limited data is available related to the prevalence and risk factors for cardiovascular disease in youth populations. 

Preventative Efforts   

A range of lifestyle factors has been shown to influence the risk of cardiovascular disease (Mente, de Koning, Shannon, & Anand, 2009). Recent data indicates that nutrition, tobacco reduction and exercise habits are the three most impactful changeable behaviors associated with lowering the risk of cardiovascular episodes (Mente et al., 2009). As a result, a vast majority of public health promotion interventions have incorporated one or more of these variables. However, few cardiovascular disease prevention efforts have focused specifically on these behaviors in youth populations (Mente et al., 2009). Exercise and physical activity interventions appear to be particularly relevant to the prevention of atherosclerosis for younger individuals, as this condition begins to develop very early in life. 

Intervention efforts for cardiovascular disease include multiple nutrition and physical activity behaviors that assist in the reduction of cholesterol and reduce body fat percentage, as well as serum cholesterol levels (Kiran, et al., 2010).  For example, diets low in saturated fat and high in fiber are strongly correlated with a low risk of cardiovascular disease (Kiran et al., 2010). It is believed that such diets serve to reduce cholesterol levels and prevent their accumulation within the arteries (Davey-Smith, Ben-Shlomo, and Lynch, 2002). Additionally, raising exercise levels has been shown to reduce cholesterol and help people of all ages achieve a healthy weight (Williams, et al., 2004). Emotional stress and chronic hypertension are both correlated with an increased risk of strokes and heart attacks (Lawlor, et al., 2005). According to Lawlor and colleagues (2005), nearly half of all people with cardiovascular disease also experience psychological problems such as anxiety and depression (Lawlor, et al., 2005). Identifying methods of reducing these psychological stressors with the goal of reducing blood pressure represents another potential avenue for reducing the risk of cardiovascular disease (Kelly & Stanner, 2003).

Kvaavik, Batty, Ursin, Huxley, and Gale (2010) evaluated the effects of an individualized dietary and nutritional health promotion program. These researchers discovered that catering diet and physical activity variables to the individual preferences of patients resulted in better adherence to a stroke and heart attack prevention efforts (Kvaavik et al., 2010). Additionally, these healthy lifestyle changes reduced the incidence of cancer in this population. Based on these results, Kvaavik and colleagues (2010) suggest that health promotion programs should be needs-based (Kvaavik et al., 2010). 

Epidemiological studies (e.g., Berlin & Colditz; 1990) abound revealing the role physical activity plays in the reduction of heart disease risk. Research (e.g., Andersen, Schnor, Schroll, & Hein, 2000) is also in abundance regarding the relationship between exercise and the reduction in all-cause mortality. Exercise interventions also appear to offer multiple beneficial effects beyond just cardiovascular disease prevention, including enhancements in general physical performance and quality-of-life. As a result of these effects, multiple public health professionals and associations (e.g., Goble & Worcester, 1999) endorse exercise as efficacious secondary prevention strategies for cardiovascular disease. However, these associations are less clear on recommendations for youth populations. 

Cardiovascular Disease Prevention in Schools

The classroom may represent a promising environment in which to reach at-risk youth populations. Substantial evidence (e.g., Berry et al., 2012) exists that policy mandating healthy diet and exercise monitoring in schools is an efficacious strategy in the fight against heart disease. Foster and colleagues (2008) evaluated the impact of a multidimensional school-wide dietary policy on the reduction of obesity in elementary school populations. Due to the high correlation between obesity and atherosclerosis, this policy promoted the usage of self-assessments, educational intervention on healthy eating and physical activity and parental participation in adhering to cardiovascular disease-preventative dietary guidelines. Results demonstrated that the policy was associated with more than a 50% reduction in obesity across the school, in addition to significantly improved eating and exercise behaviors (Foster et al., 2008). 

Despite the fact that parents and guardians are responsible for the diets of their children, the national and international consequences of cardiovascular disease necessitate governmental intervention (Friedman & Scwartz, 2008). The academic environment serves as a prime opportunity in which to deliver lifelong health promotion strategies that will promote a healthier and more economically viable national outlook (Al-Naqeeb, 2010). Factors that comprise ideal cardiovascular health perpetually change based on new research (Al-Naqeeb, 2010). However, dietary intervention and physical activity appear to be the two most important strategies in which to educate youth populations (Drewnowski & Darmon, 2005). Schools face a responsibility to offer nutritious, affordable alternatives to junk food and other unhealthy dietary choices students (Drewnowski & Darmon, 2005). Due to time and economic constrictions, many low-socioeconomic families lack possess the means to enforce optimal lifestyle choices in their young children (Drewnowski & Darmon, 2005). As a result, the elementary school system seeks ways to better meet the needs of these families.

Gaps in Research

Numerous limitations have potentially detracted from the quality and validity of previous health prevention efforts aimed at youth populations. In addition to the general lack of research in this area, it is difficult to distinguish between genetic contributions to cardiovascular disease risk, and those generated by healthy lifestyle interventions (Bowling, 2009). Researchers are still exploring the role of genetics and modifiable behaviors play in the course of cardiovascular disease. Research has unequivocally shown that those interventions incorporating changeable factors such as diet and exercise have been successful in the reduction of cardiovascular disease risk (Berry et al., 2012). However, a lack of longitudinal data beginning in youth populations has limited the ability to explore these relative contributions over time. 

Lennon, Galvin, Smith, Doody, and Blake (2013) also performed a comprehensive revaluation of current healthy lifestyle programs designed to prevent strokes and heart attacks. Based a review of 17 randomized controlled studies (RCTs), including approximately 2,500 individual cases, Lennon and colleagues (2013) concluded that the quality of research is lacking in many ways. Among one of the more pertinent limitations of existing research is the failure to evaluate longitudinal cardiovascular disease risk factors beginning in early childhood (Lennon et al., 2013). 

An additional problem associated with existing research related to cardiovascular disease prevention in youth is the expense of conducting such studies. For example, Labarthe and Dunbar (2012) contend that interventions aimed at reducing salt intake or smoking on an international level are too costly and impractical for many nations that experience the highest rates of cardiovascular disease. While more detailed economic evaluations are needed to ascertain the practicality of cardiovascular disease prevention efforts in youth, public health professionals estimate that the costs resulting from cardiovascular disease significantly outweigh those of preventative efforts (Labarthe & Dunbar, 2012). Therefore, future research is needed relating to identifying critical preventative factors and intervention strategies for school-aged populations.

Research Methodology

This section includes an outline of the research methodology used in the current study. The study design is first outlined, followed by a detailed description of the variables of measurement drawn from the two data sets. Finally, an explanation of the study participants and the sample population will be included. 

Study Design

The current study utilized a retrospective cross-sectional design to determine the impact of key physical activity and nutritional variables in the prevalence of cardiovascular disease. Drawing on the two data sets described above, this study compared the population effects of these variables to estimate the risk of developing cardiovascular disease and other cardiovascular disorders. A cross-sectional design is an effective and low-cost method of gaining insight into the epidemiology of public health problems and does not require the acquisition of new data (Berlin & Colditz, 1990). 

Study Variables and Measures

This study utilized combined data from both the High School Youth Risk Behavior Survey and the National Health and Nutrition Examination Survey, 2009-2010. The former contains 18 unique nutritional variables designed to assess key healthy eating behaviors in high school populations. These variables include the consumption of whole fruit juices, fruits, vegetables, and soda. Additionally, the High School Youth Risk Behavior Survey contains eight variables related to physical activity, including total amount of physical activity obtained, involvement in sports and sedentary behaviors (e.g., video game playing and television watching). The National Health and Nutrition Examination Survey, 2009-2010, contains data on cardiovascular disease prevalence in youth populations. Conglomerate scores were given to all nutritional and physical activity data to determine significant differences in cardiovascular disease prevalence between those who reported healthy dietary and physical activity behaviors versus those who did not. While it is acknowledged that previous research (e.g., Drewnowski & Darmon, 2005) has already been conducted revealing the impact of nutrition and physical activity on cardiovascular disease, this study will provide current statistics related to this subject, as well as up-to-date information on the precise impact of these factors on cardiovascular disease risk. 

Study Participants

In the High School Youth Risk Behavior Survey, participants included approximately 15,000 students in the United States ranging from ages 14 to 18. The exact number of participants varied from one item to the next, so a weighted score was provided for each variable based on the percentage of the sample that responded to each question. Each item contained approximately 50% males and 50% females. As the goal of this study was not to determine gender-related differences in cardiovascular disease risk, this variable was not factored into the statistical analysis. In the National Health and Nutrition Examination Survey, 2009-2010, data were filtered to only utilize respondents aged 14 to 18 in order to compare data with the High School Risk Behavior Survey. As the actual prevalence of cardiovascular disease in children this age is relatively low, a conglomerate score was granted to widely documented risk factors for this health problem, including angina, shortness of breath, high blood pressure.

Data Analysis

To evaluate the impact of nutritional and exercise variables on cardiovascular disease prevalence, simple student's t-tests were conducted for a range of variables from the data sets described above. First, t-tests were run to determine any significant differences in cardiovascular disease prevalence for the combined nutritional data from the High School Youth Risk Behavior Survey and the prevalence of cardiovascular disease risk factors from the National Health and Nutrition Examination Survey, 2009-2010. Additionally, t-tests were run to determine any significant differences in cardiovascular disease prevalence for the combined physical activity data and cardiovascular disease risk factors from the National Health and Nutrition Examination Survey, 2009-2010. A conglomerate mean score was given to each variable based on the percentage of respondents who responded either affirmatively to each of the nutritional and physical activity questions. The results of this data analysis are presented below. 

(Table 1 omitted for preview. Available via download)

As can be seen in Table 1, substantially more high school students in the United States reported healthy nutritional habits. Additionally, the respondents who reported healthier eating habits demonstrated reduced risk factors for cardiovascular disease, t(15,072) = 243.94, p = 0.0001. This finding was expected and confirms previous research related to healthy nutritional habits and cardiovascular disease risk in youth populations.

(Table 2 omitted for preview. Available via download)

Results presented in Table 2 demonstrate that a slightly higher percentage of high school-aged students in the United States report obtaining sufficient levels of physical activity than those who do not. Additionally students who obtain higher levels of physical activity experience reduced risk factors for cardiovascular disease, t(15,590) = 94.42, p = 0.0001. This finding was also expected and confirms previous research related to health exercise habits and cardiovascular disease risk in youth populations.  

Conclusion

The purpose of this study was to determine current risk factor statistics for cardiovascular disease in youth populations. Specifically, this study compared data from the High School Youth Risk Behavior Survey and the National Health and Nutrition Examination Survey, 2009-2010 to evaluate variables related to healthy eating, physical activity participant and individual risk factors for cardiovascular disease. While substantial research exists pertaining to the impact of these variables on cardiovascular disease, this study aimed to provide current statistics specifically for high school-aged children in the United States. Results from this study confirmed previous research, demonstrating that widely documented healthy lifestyle behaviors are efficacious in preventing early warning signs for cardiovascular disease. While cardiovascular disease contains a strong genetic component, the evidence presented in this study suggests that healthy dietary and physical activity habits can help mediate these hereditary contributors. The information gained from this study may be useful to public health professionals seeking to gain support for early cardiovascular disease prevention efforts in young students. 

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