Factors Influencing the Parathyroid Hormone Response in Hemodialysis Patients

Abstract

PURPOSE OF STUDY: Adynamic bone disease (ABD) indicates a significant risk factor for morbidity and mortality, therefore risk factors for ABD should be investigated. In this study we aimed to determine the contributing factors for ABD and parathyroid hormone (iPTH) response in HD patients. METHODS: A series of 139 patients (age: 47.8 ± 13.8 years, HD duration: 67.1 ± 52.7 months) were included. Five years data about the patients clinical therapy and cumulative calcium dose) and laboratory features were collected. Patients were divided into three groups as those with low, intermediate and high iPTH: Group I (iPTH 300 pg/ml n:59). We excluded the patients who received calcitriol therapy after the initiation of HD from group I. RESULTS: When the groups were compared, patients in-group I had significantly shorter HD duration (54.5 ± 40.1 and 72.8 ± 54.3 months, p < 0.04), higher mean calcium and lower phosphorus levels (p < 0.0001, p < 0.0001), higher total cholesterol (p < 0.001), CRP (p < 0.02), fibrinogen (p < 0.005), and ferritin (p < 0.01) levels than those in-group II and III. A higher calcium phosphorus product (44.7 ± 12.5 and 50.9 ± 12.4, p < 0.0005) and presence of rHuepo resistance (p < 0.003) were strikingly different between Group II and III. According to the multivariate analysis, follow-up data of higher calcium (p < 0.0001) and fibrinogen (p < 0.03); lower phosphorus (p < 0.001) levels were significant determinants of low PTH levels. CONCLUSION: Even small changes in calcium phosphorus balance can influence a wide spectrum of parathyroid hormone response in long-term follow-up. Underlying inflammation is an additional risk factor for the development of adynamic bone disease, which could explain the potential co-morbidity of this clinical condition.