PTH and chronic kidney disease: The novel finding of our study is that when time-varying ∆PTH was added into the model, the longitudinal increment of serum PTH acted as a predictor of renal death independent of basal fixed covariate, i.e. older age, CKD stage, serum levels of PTH and phosphate, and, more important, independently from proteinuria, that is considered the main risk factor of CKD progression [32].