Figure 15: Linear regression of Urinary Ni with age (top diagram), quantilenormalized and log transformed AGA for GID = 191 with the age (middle diagram), and Urinary Ni with creatinine (bottom diagram). The diagrams show R-squared values, regression coefficients with their p-values and the Pearson correlation coefficient. The low Pearson correlation coefficients in the first two diagrams indicate that there is no association of Urinary Ni or AGA with the age of subjects in this study. The relatively high correlation between Urinary Ni and creatinine suggests that these factors are potentially interchangeable in our analysis.