The fundamental objectives of this proposal are two-fold: 1) to evaluate risk factors for and sequelae of thyroid functional disease in patients with impaired renal function and 2) to promote development towards a career as an independent clinical investigator. Both chronic kidney disease and thyroid dysfunction are common in the US population, and both are known to adversely affect cardiovascular health in survival. Prior evidence indicates that there is an increased prevalence of thyroid disease in patients with chronic kidney disease and end-stage renal disease, which occurs in proportion to the degree of renal injury. Aim 1 will explore one potential mechanistic link for this association, namely whether thyroid disease is promoted by exposure to iodinated contrast media in the setting of decreased renal excretory capacity. There is uncertainty as to whether, and in which direction, hyper- and hypothyroidism may influence mortality in the end-stage renal disease population based on limited data, and there has been no study of the associations of hyper- and hypothyroidism and mortality among patients with pre-end-stage chronic kidney disease. Aim 2 will explore whether the association between thyroid dysfunction and cardiovascular and all-cause mortality is magnified in the context of renal dysfunction. Aim 1 will be explored using a retrospective cohort of patients cared for by Harvard Vanguard Medical Associates, a large, community based multispecialty group that services a diverse patient population and provides comprehensive capture of co-morbidity, procedural, and medication data. Aim 2 will be explored using the Third National Health and Nutrition Examination Survey data which provides detailed cross-sectional data and longitudinal mortality follow-up on a representative sample of the US population. This study will provide valuable data that both informs clinical practice and guides future research. Moreover, the proposed study will provide additional experience in applying tenants of study design, data analysis, statistical programming, and scientific writing, in paralle with didactic training in the Master of Science in Epidemiology program at the Harvard School of Public Health. The combination of formal didactics, experience in the conduct of research, opportunity to create a publication track record, and mentorship provided by the sponsor and collaborators will promote development towards becoming an independent investigator. Furthermore, this research endeavor will provide the practical experience and data necessary for development and submission of a Mentored Career Development Award application, which will be formulated toward the end of the period under award. PUBLIC HEALTH RELEVANCE: Both chronic kidney disease and thyroid dysfunction are common in the US population, and both are known to adversely affect cardiovascular health in survival. Prior evidence indicates that there is an increased prevalence of thyroid disease among patients with chronic kidney disease and end-stage renal disease. This study will explore 1) whether thyroid disease is promoted by exposure to iodinated contrast media in the setting of impaired renal function and 2) whether the cardiovascular and all-cause mortality of thyroid dysfunction are magnified in the context of impaired renal function.