Supplementary Material for: Increased Levels of Copeptin, a Surrogate Marker of Arginine Vasopressin, Are Associated with an Increased Risk of Chronic Kidney Disease in a General Population

<i>Background:</i> Our aim was to test if plasma copeptin, a stable surrogate marker of arginine vasopressin, predicts decline of glomerular filtration rate (GFR) and risk of chronic kidney disease (CKD). <i>Methods:</i> We measured copeptin and renal function at the Malmö Diet and Cancer Cardiovascular Cohort baseline exam and reassessed renal function after a follow-up time of 16.6 ± 1.5 years (n = 3,186). Furthermore, we defined CKD based on an estimated GFR (eGFR) calculated by the Modification of Diet in Renal Disease (MDRD) <60 (CKD_60MDRD), <45 (CKD_45MDRD) and <30 (CKD_30MDRD) ml/min/1.73 m2. <i>Results:</i> After multivariate adjustment (gender, age, baseline eGFR, smoking status, systolic blood pressure, antihypertensive treatment and follow-up time), copeptin (beta-coefficient per 1 SD increment of copeptin) was independently associated with significantly greater annual decline of eGFR (ml/min/1.73 m2) according to the MDRD formula (OR 0.057, 95% CI 0.022-0.093; p = 0.001) as well as according to the CKD Epidemiology Collaboration (CKD-EPI) formula (OR 0.050, 95% CI 0.022-0.077; p < 0.001). Each SD increment of copeptin independently predicted incident CKD_60MDRD (OR 1.19, 95% CI 1.04-1.36; p = 0.010), CKD_45MDRD (OR 1.33, 95% CI 1.04-1.71; p = 0.026) and CKD_30MDRD (OR 3.69, 95% CI 1.41-9.66; p = 0.008). The relationship between copeptin and CKD defined by CKD-EPI gave similar results. <i>Conclusion:</i> Our data suggest that increased levels of copeptin independently predict decline in eGFR and greater risk of new-onset CKD.