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

Abstract 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 multicen- tre cohort study, incident haemodialysis patients were re- cruited 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 con- ditions 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 in- verse correlation was observed between CCI (excluding age) and iPTH (P = 0.00002). Independently of CCI, pa- tients with iPTH <150 pg/ml had 76% as high as the risk of all-cause mortality. After multivariable adjustment, the combination of the first tertile of iPTH with second and third tertiles of CCI was significantly associated with all- cause mortality (RR = 3.83, P = 0.02; RR = 3.79, P = 0.01, respectively). Conclusions. Incident haemodialysis patients suffer from a high rate of clinical complications. In these patients, low iPTH and high CCI are often associated and very likely responsible for an adverse outcome