Fig. 6

Scheme of older dialysis patients and heterogeneities. Conceptually, two types of age expression can be considered in a single patient, actual and chronological ages. The chronological age is usually used to determine the age of patients, while health age is a conceptual age and it determines the phenotype of the patients. During the normal aging process, the two ages are identical. Patients are considered frail when their health ages are higher than their actual ages. Importantly, the disparities or the heterogeneities across patients are wider in the older population