School
School of Public Health
Document Type
Dissertation
Department (new version)
Public Health
Date of Award
2002
Degree Name by School
Doctor of Public Health (DrPH) School of Public Health
Abstract
Generalizability of possible seasonality of cardiovascular disease risk factors has not been demonstrated, and, if present, biologic mechanisms remain uncertain. This was addressed by examining cross-sectional seasonal variation in cardiovascular disease risk factors among Coronary Artery Risk Development in Young Adults (CARDIA) subjects, and cross-sectional and longitudinal seasonal variation in and interrelationships between lipids and thyroid hormone levels in a Lipid Variation Influence of Stress (LVIS) study subsample. Although crude analyses identified some significant seasonal variation in low density lipoprotein (LDL) cholesterol, physical activity, maximum heart rate, caloric intake, triglycerides, body weight and blood pressure overall and/or among race/gender strata among CARDIA subjects; interaction of season and age or race removed the significant seasonal variation. There were significant longitudinal seasonal variations in high density lipoprotein (HDL) cholesterol, thyroid stimulating hormone (TSH), and weight, adjusting for all potential confounding variables among LVIS subjects. Addition of weight removed significant seasonal variation in HDL cholesterol, but not TSH. Thyroid hormone levels did not contribute to the seasonal variation of HDL cholesterol, and seasonal variation in weight appeared to result from the interaction between season and stress and season and saturated fat. It was concluded that seasonal variation seen in CARDIA stemmed from seasonal recruitment differences by age and/or race, and any seasonal variation, if present, was minimal. HDL cholesterol and TSH in the LVIS subsample demonstrated seasonal variability, but TSH did not appear to influence lipid variability. Overall, little evidence for much seasonal variation in cardiovascular disease risk factors was found. Based on these results, any seasonality in cardiovascular disease risk factors in healthy young adults, if it exists, appears to be too small to be of much clinical or even epidemiologic significance. In addition, thyroid function does not appear to be an important determinant of lipid seasonal variability. Last, it is recommended that age and race recruitment distribution be taken into consideration when analyzing cross-sectionally for risk factor seasonality.
ProQuest Publication Number
ProQuest ID
3042719
ISBN
978-0-493-56361-9
Recommended Citation
Robbins, Donna Garland, "Seasonality of cardiovascular disease risk factors" (2002). All ETDs from UAB. 7223.
https://digitalcommons.library.uab.edu/etd-collection/7223
Comments
DrPH