Mineral and bone disorder biomarkers and inflammation indexes in patients with end stage renal disease

Chronic kidney disease (CKD) is an independent risk factor for bone and mineral metabolism disorder. Bone and mineral metabolism disorder develop gradually with the progression of renal failure. Various abnormalities include elevated fibroblast growth factor-23, decreased levels of 1,25-Dihydroxy Vitamin D (1,25-(OH)2D), and secondary hyperparathyroidism. This study aimed to evaluate the biomarkers and inflammation indexes of CKD-mineral and bone disorder (MBD), and to examine the associations of serum alkaline phosphatase (ALP) levels with serum C-reactive protein (CRP) levels and leukocyte count, in patients with end-stage renal disease (ESRD). ESRD patients who were yet to initiate dialysis were enrolled as the study subjects. All CKD patients who were discharged from our hospital between January 1, 2013, and December 31, 2017, were screened. Based on quartiles of serum ALP, all subjects were categorized into four subgroups. The clinical characteristics of patients in the four subgroups were investigated. The prevalence of hypocalcemia, hyperphosphatemia, elevated intact parathyroid hormone (iPTH), and elevated CRP level was calculated in the four subgroups. The association between serum ALP and inflammation indexes was examined using regression analysis. Based on the inclusion criteria and exclusion criteria, 256 cases with ESRD were included in our study. The overall prevalence of hypocalcemia and hyperphosphatemia was 57.81% and 89.84%, respectively. Of the patients with ESRD, 174 (68.75%) had an elevated iPTH level >2 times of the upper limit of normal value), and 40 (15.63%) had an elevated iPTH level >9 times of the upper limit of normal value Discrepancies between serum ALP and iPTH levels were found in 29 patients. In the adjusted model, log-transformed CRP, log-transformed iPTH, and leukocyte count were significantly associated with log-transformed ALP. Hypocalcemia, hyperphosphatemia, and increased levels of iPTH and CRP were found to be extremely common in ESRD patients. Discrepancies between serum ALP and iPTH were also observed. Our results also indicate that serum ALP level is associated with the levels of iPTH and CRP, as well as leukocyte count.