Interaction between parathyroid hormone and the Charlson comorbidity index on survival of incident haemodialysis patients

Background. Haemodialysis patients are ageing and have with a high rate of comorbidities. The impact of this novel clinical setting on intact parathyroid hormone (iPTH) is not well established. Methods. For this observational, prospective multicentre cohort study, incident haemodialysis patients were recruited in 40 Italian centres and followed up for a mean period of 18 ± 6.7 months. Clinical characteristics and biochemistry were recorded at baseline. Comorbid conditions were scored by the Charlson comorbidity index (CCI). Results. Data of 411 patients (mean age: 66.5 ± 14.8 years; 17.3% >80 years old) were recorded. The mean CCI was 4.17 ± 2.8. In patients with CCI >0, an inverse correlation was observed between CCI (excluding age) and iPTH (P = 0.00002). Independently of CCI, patients with iPTH