Cross-sectional survey of the association of calcium and phosphorus metabolism with parathyroid hormone levels in maintained hemodialysis patients

Objective To investigate the control rate of calcium-phosphorus metabolism and parathyroid hormone in maintained hemodialysis patients in the First Affiliated Hospital of Dali University according to K/DOQI guidelines. Relating risk factors will be further explored to provide evidence for treatment.Methods Serum calcium and phosphorus, albumin, alkaline phosphatase (ALP), parathyroid hormone (iPTH) levels were detected in 128 maintained hemodialysis patients, and the control rate of those makers was analyzed according to the K/DOQI guidelines. Patients were grouped by the age (≤ 45 and >45 age group), residual urine volume (anuria groups:urine volume <100 ml/d and urinary groups:urine volume ≥ 100 ml/d), dialysis age (<3 years and ≥ 3 years group), dialysis adequacy (eKt/V ≥ 1.2 and eKt/V<1.2), and compared the difference of serum calcium, phosphorus and calcium phosphorus product, ALP, iPTH, URR%, eKt/V index between groups. Stepwise multivariable regression analysis was used to investigate the relationship of iPTH with age, dialysis age, serum calcium, serum phosphorus, calcium phosphorus product, albumin, ALP, serum urea nitrogen and creatinine as well as residual urine volume.Results The control rate of serum calcium, phosphorus, calcium-phosphorus product, iPTH were 48.4%, 42.2%, 58.6% and 25%, respectively. All the four makers were under control in 12 patients (9.38%). There was significant difference in serum phosphorus and calcium-phosphorus product between patients ≤ 45 years and those >45 years patients (P<0.05). The difference of iPTH levels between anuria patients and urinary patients was significant (P<0.05). There was also significant difference in URR% between adequate dialysis patients and inadequate dialysis patients (P<0.05). iPTH was negatively correlated to the duration of dialysis and serum calcium, and positively correlated with serum phosphorus, alkaline phosphatase and creatinine.Conclusions The control rates of calcium-phosphorus metabolism and parathyroid hormone in maintained hemodialysis patients in our hospital were lower. Serum phosphorus levels were difficult to control in younger patients, and the protection of residual urine might be helpful to control iPTH.