[Renal disease-related clinical examination in a cohort study]

Various clinical examinations are utilized as variables, surrogate markers, and outcomes in a cohort study. Since the significance of chronic kidney disease as a risk for cardiovascular diseases and premature death was reported, the number of studies including renal disease-related clinical examinations is increasing. Depending on the purpose of the study, renal parameters including the glomerular filtration rate (GFR), proteinuria/albuminuria, hematuria, renal tubular markers, uric acid, bone mineral disorders, and anemia are examined. Among these parameters, GFR and proteinuria/albuminuria are the most frequently used. These parameters are independently associated with the risk of various events, and the combination of these parameters improves the ability to predict the outcomes. Additionally, recent progress in molecular biology has allowed us to include genetic factors as clinical parameters in cohort studies. To investigate the association between the genetic predisposition and outcome, candidate gene analysis and, more recently, genome-wide analysis, are performed. These methodologies are very useful to explore new factors and clarify the underlying mechanisms of the target diseases. Most of the lifestyle-related diseases are multi-factorial, and the association between each factor and the event are sometimes modulated by characters of the examined population. Therefore, careful selection and evaluation of clinical examinations are very important for precise risk evaluation in a cohort study.