University of South Carolina Scholar Commons Theses and Dissertations Spring 2020 The Interaction Between Caffeine Consumption, Alcohol Use, and Amount of Sleep on Bone Health Haley Davis-Martin Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Clinical Epidemiology Commons Recommended Citation Davis-Martin, H.(2020). The Interaction Between Caffeine Consumption, Alcohol Use, and Amount of Sleep on Bone Health. (Master's thesis). Retrieved from https://scholarcommons.sc.edu/etd/5796 This Open Access Thesis is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. THE INTERACTION BETWEEN CAFFEINE CONSUMPTION, ALCOHOL USE, AND AMOUNT OF SLEEP ON BONE HEALTH by Haley Davis-Martin Bachelor of Arts University of South Carolina, 2017 ___________________________________________________________ Submitted in Partial Fulfillment of the Requirements For the Degree of Master of Science in Public Health in Epidemiology Arnold School of Public Health University of South Carolina 2020 Accepted by: Matthew Lohman, Director of Thesis Susan Steck, Committee Member Fei Fei Xiao, Committee Member Cheryl L. Addy, Vice Provost and Dean of the Graduate School © Copyright by Haley Davis-Martin, 2020 All Rights Reserved. ii Abstract Using cross-sectional data from the 2009-2010 and 2013-2014 NHANES surveys we examined potential interaction between caffeine consumption, alcohol use, and sleep and its relation to bone health, measured using bone mineral density (BMD). The study population consisted of 2,405 individuals at least 40 years old who were not taking any medications or hormones that would affect bone mineral density. Several factors such as smoking status, exercise, dietary intake of calcium, dietary intake of vitamin D, dietary intake of phosphorus, presence of arthritis, age, gender and race were considered in this project. We found a statistically significant negative linear relationships between femur BMD and caffeine consumption and a statistically significant positive linear relationship between the estimated risk of major osteoporotic fracture and caffeine consumption for both those who did and did not have a previous fracture. We found no evidence of interaction between caffeine, alcohol, and sleep in regard to bone health. iii Table of Contents Abstract .............................................................................................................................. iii List of Tables ...................................................................................................................... v List of Figures .................................................................................................................... vi Chapter One: Introduction .................................................................................................. 1 Chapter Two: Literature Review ........................................................................................ 4 Caffeine and Bone Health ............................................................................................... 4 Alcohol and Bone Health ............................................................................................... 6 Sleep and Bone Health ................................................................................................... 8 Interactions between Exposures ................................................................................... 10 Other Factors ................................................................................................................. 12 Summary ....................................................................................................................... 15 Chapter Three: Methods ................................................................................................... 16 Study Design ................................................................................................................. 16 Measurement of Exposure ............................................................................................ 16 Measurement of Outcome ............................................................................................. 18 Measurement of Effect Modifiers ................................................................................. 22 Measurement of Confounders ....................................................................................... 23 iv Statistical Analysis ........................................................................................................ 25 Chapter Four: Results ....................................................................................................... 28 Spine Bone Mineral Density ......................................................................................... 28 Femur Bone Mineral Density – Two Categories .......................................................... 32 Femur Bone Mineral Density – Three Categories ....................................................... 36 Secondary Analyses ..................................................................................................... 40 Chapter Five: Discussion .................................................................................................. 47 v List of Tables Table 2.1: Demographics of study participants by two level bone mineral density categories by scan site ...................................................................................................... 19 Table 2.2: Demographics of study participants for three level femur bone mineral density categories ......................................................................................................................... 21 Table 3.1: Chi-Square results comparing factors of interests and potential covariates with spine BMD ....................................................................................................................... 29 Table 3.2: Adjusted odds ratios (OR) and 95% confidence intervals (CI) for low spine bone mineral density (BMD) ........................................................................................... 30 Table 3.3: P-values for the interaction analysis for spine BMD ....................................... 32 Table 3.4: Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the interaction between alcohol and sleep for spine BMD ..................................................... 32 Table 3.5: Chi-Square results comparing factors of interests and potential covariates with femur BMD at two levels ................................................................................................. 34 Table 3.6: Adjusted odds ratios (OR) and 95% confidence intervals (CI) for low femur BMD ................................................................................................................................. 35 Table 3.7: P-values for the interaction analysis for femur BMD ...................................... 36 Table 3.8: Chi-Square results comparing factors of interest and potential covariates with femur BMD at three levels ............................................................................................... 37 Table 3.9: Adjusted odds ratios (OR) and 95% confidence intervals (CI) for femur BMD by BMD category ............................................................................................................. 39 Table 3.10: P-values for interaction analysis for three levels of femur BMD .................. 40 Table 3.11: Linear regression results for femur BMD and spine BMD adjusted for age, gender, race, and smoking status ...................................................................................... 41 vi Table 3.12: Linear regression results for hip FRAX scores based on previous fracture status adjusted for age, gender, calcium intake, phosphorus intake, and smoking status ........................................................................................................................................... 43 Table 3.13: Linear regression results for major osteoporotic FRAX scores based on previous fracture status adjusted for age, gender, calcium intake, smoking, and arthritis ........................................................................................................................................... 45 Table 3.14: P-values for interaction analysis for all linear regression models ................. 46 vii List of Figures Figure 2.1: Flow chart demonstrating change in size of study population by various exclusion criteria .............................................................................................................. 17 Figure 3.1: Linear model of femur BMD by average caffeine intake (mg) with 95% confidence limits and prediction limits ............................................................................. 41 Figure 3.2: Linear model of spine BMD by average caffeine intake (mg) with 95% confidence limits and prediction limits ............................................................................ 42 Figure 3.3: Linear model of 10-year risk of hip fracture (FRAX) for those who had a previous fracture by average caffeine intake (mg) with 95% confidence limits and prediction limits ............................................................................................................... 43 Figure 3.4: Linear model of 10-year