Purpose of the Study
Upon the realization that sugar-sweetened beverages (e.g., soft drinks/sodas, fruit-flavored drinks, sports drinks, and energy drinks) are closely associated with adverse health outcomes such as elevated risks of obesity, metabolic syndrome, type 2 diabetes and cardiovascular disease, the authors in this particular study set out to investigate whether leukocyte telomere length maintenance is a mediating factor in the relationship between consumption of sugar-sweetened beverages and cardiometabolic risk. Available knowledge prior to the research study demonstrated that leukocyte telomere length maintenance is responsible for healthy cellular aging and that the harmful effects associated with sugar-sweetened beverages (e.g., oxidative stress, inflammation and insulin resistance) were to blame for telomere shortening; however, it was not fully understood how impairment of the leukocyte telomere length could help explicate the relationship between the consumption of these beverages and elevated metabolic disease (Leung et al., 2014). As demonstrated in the literature, the purpose of this study is nested on deductive reasoning, which moves from the general to the specific in an attempt to establish the inferences between the various variables of interest (World Health Organization, 2001).
Hypothesis
The authors of the study intended to test the hypothesis that “beverages with high sugar content would be the most detrimental to cellular aging such that sugar-sweetened sodas and non-carbonated SSBs would show the strongest associations with telomere shortness” (Leung et al., 2014, p. 2426). As indicated in the literature, an inferential supposition between sugar-sweetened beverages and telomere shortness has been made with the view to posing a testable hypothesis which will in turn advance knowledge in science (World Health Organization, 2001).
Study Variables
Drawing from the above exposition, it is evident that the independent variable in the study is the consumption of sugar-sweetened beverages, while the dependent variable is the risk of cardiometabolic disease. It can be argued that telomere length forms the mediating variable in the study.
Research Methodology
Study Participants
The study enrolled 5,309 adults from the 1999-2002 National Health and Nutrition Examination Surveys using two main inclusion criteria, namely age (between 20 and 65 years) and health status (no prior history of diabetes and cardiovascular conditions such as coronary heart disease, angina, myocardial infarction, stroke or congestive heart failure). Manolio et al (2012) argue that recruiting participants using a structure (e.g., use of the 1992-2002 National Health and Nutrition Examination Surveys) enhances or facilitates determination of study outcomes in most health-related surveys.
Study Design
The study used a quantitative research approach and a cross-sectional research design, which enabled the authors to examine the relationship between consumption of sugar-sweetened beverages and telomere length using various groups of individuals who differed in the above-named variables but shared other typical characteristics, such as sociodemographic variables, health-related variables, and adiposity measures (Leung et al., 2014).
Data Collection Procedures
DNA samples purified from whole blood were collected from the participants and processed by the Division of Laboratory Sciences at the National center for Environmental Health using the quantitative polymerase chain reaction (PCR) technique with the view to evaluating telomere length relative to standard reference DNA. Additionally, one 24-hours dietary recall was administered to the study participants at a Mobile Examination Center and analyzed to identify consumption of SSBs using predetermined measures originating from USDA Food and Nutrient Database for Dietary Studies (Leung et al., 2014).
Statistical Analysis
From the study, it is evident that the arising data were analyzed using a multiplicity of statistical procedures, including univariate analysis to describe sociodemographic characteristics, bivariate analysis to test relationships between variables, as well as statistical significance tests to establish relationships (Leung et al., 2014).
References
Leung, W.C., Laraia, B.A., Needham, B.L., Rehkopf, D.H., Adler, N.E., Lin, J…Epel, E.S. (2014). Soda and cell aging: Associations between sugar-sweetened beverage consumption and leukocyte telomere length in healthy adults from the national health and nutrition examination surveys. American Journal of Public Health, 104(12), 2425-2431.
Manolio, T.A., Weis, B.K., Cowie, C.C., Hoover, R.N., Hudson, K., & Kramer, B.S. (2012). New models for large prospective studies: Is there a better way? American Journal of Epidemiology, 175(9), 859-866.
World Health Organization. (2001). Health research methodology: A group for training in research methods (2nd ed.). Web.