Abstract: 【Abstract】Objective To investigate the relationship between serum levels of microRNA- 155 (miR-155) and programmed cell death 4(PDCD4) and disorder of calcium and phosphorus metabolism in maintenance hemodialysis (MHD) patients. Methods A total of 86 MHD patients treated during September 2018 to October 2020 in Yanjiao People's Hospital of Sanhe City for more than 3 months and with stable conditions were recruited as the study group, and 80 healthy people for physical check-up in our hospital were selected as the control group. Serum PDCD4 and high-sensitivity C-reactive protein (hs-CRP) were assayed by ELISA,
hemoglobin and serum albumin, calcium, phosphorus and intact parathyroid hormone (iPTH) were detected by automatic biochemical analyzer, and serum miR-155 was determined by fluorescence quantitative PCR. General information of the patients was analyzed. Serum miR-155 and PDCD4 levels were compared between the study group and the control group. The MHD patients were further divided into subgroups based on age, dialysis vintage and dialysis frequency, and serum miR-155 and PDCD4 levels were then compared among the subgroups. The MHD could be further grouped into the high expression group and the low expression group based on their average serum miR-155 and PDCD4 levels; calcium and phosphorus metabolism were then analyzed between the two groups. Logistic regression analysis was used to evaluate the risk factors for calcium and phosphorus metabolism disorder in MHD patients. Results Serum albumin was significantly lower in the study group than in the control group (t=8.848, P<0.001), but serum phosphorus, iPTH, hs-CRP, miR-155, and PDCD4 levels were significantly higher in the study group than in the control group (t=10.491, 3.578, 10.988, 16.298 and 19.419 respectively; P<0.001). Serum miR-155 and PDCD4 levels were higher in the MHD patients with age ≥60 years, dialysis vintage ≥3 years and dialysis frequency >2 times/week than those with age <60 years, dialysis vintage <3 years and dialysis frequency 2 times/week (t=13.723, 7.773, 4.846, 15.740, 10.206 and 5.154, respectively; P<0.001). The compliance rates of serum calcium, phosphorus and iPTH were lower in the high expression group than in the low expression group. The expression levels of miR- 155 and PDCD4 were correlated with the serum levels of calcium, phosphorus and iPTH (Z=21.333, 7.898, 7.407, 15.712, 9.234 and 7.899, respectively; P <0.001, 0.019, 0.025, <0.001, 0.010 and 0.019, respectively). Multivariate logistic regression analysis showed that serum albumin (OR=2.431, 95% CI: 1.38～
4.258, P=0.002), miR-155 (OR=2.715, 95% CI: 1.433～5.144, P=0.002) and PDCD4 (OR=2.629, 95% CI:1.429～4.836, P=0.002) were the independent risk factors for calcium and phosphorus metabolism disorder in MHD patients (P<0.05). Conclusion Serum miR-155 and PDCD4 levels were correlated with calcium and phosphorus metabolism and iPTH in MHD patients. High serum levels of miR-155 and PDCD4 were the independent risk factors for calcium and phosphorus metabolism disorder in MHD patients.

Key words: Maintenance hemodialysis, microRNA-155, Programmed cell death 4, Calcium and phosphorus metabolism disorder, Relationship