Risk Factors And Effect On Prognosis Of Hyperphosphatemia In Critical Ill Patients

Background:Phosphorus ranks the sixth in the content of all elements necessary for human body and is involved in the metabolism and structur of human body.Phosphorus in body mainly comes from food.After being absorbed into the body,it mainly exists in the form of inorganic and organic phosphorus.Inorganic phosphorus mainly exists in the form of phosphate(PO3-4)in bones,teeth,blood and tissue fluids.Organic phosphorus is an important component of DNA,cell membranes and proteins.The absorption,excretion and distribution of phosphorus are mainly regulated by parathyroid hormone,1,25-dihydroxy vitamin D3 and fibroblast growth factor 23.It is the homeostasis of phosphorus metabolism that enables the cell to maintain optimal function.Various factors can lead to abnormal serum phosphorus concentration.Studies have suggested that hypophosphatemia may lead to rhabdomyolysis,respiratory failure,hemolysis,left ventricular dysfunction,impaired chemotactic function of leukocytes,and increased oxygen binding of red blood cells.Hyperphosphatemia was associated with increased incidence and mortality of cardiovascular disease,tissue calcification and left ventricular hypertrophy.Objective : The purpose of this study is to uncover the relationship of hyperphosphatemia and outcomes,and the risk factors of hyperphosphatemia by using the large number of clinical data collected by the naval military medical university affiliated Changzheng hospital emergency department for many years.And propensity score methods can improve the credibility of the conclusion,furthermore,we used the MIMIC-? data to verify this conclusion.Finally the blank of the related research at China and abroad in critical ill patients can be filled.Methods:we defined 28 days death as the end events,this study mainly use the survival curve,multivariate Cox proportional hazards model and Propensity score matching(PSM)analysis and Propensity score weighting,(PSW)to estimate the relationship between hyperphosphatemia and the major end events,and the similar analysis were performed with the data from the third edition of MIMIC-III database to evaluate the generality of our main results.Results:A total of 3747 samples were included in this study.The mortality of patients with hyperphosphatemia was significantly higher than that of the patients with normal blood phosphorus(13.0%VS3.7%,p < 0.001).Cox proportional risk model showed that the mortality hazard ratio(HR)of patients with hyperphosphatemia was significantly higher than that of patients with normal serum phosphate(HR 1.88,95% CI 1.35-2.60,P < 0.001).Major risk factors for hyperphosphatemia include age,creatinine,SOFA score,hypocalcemia,and diabetes.After most of the unbalanced confounding covariates were eliminated by propensity score matching and IPTW-based propensity score weighting,the mortality hazard ratio of patients with hyperphosphatemia was still significantly higher than that of patients with normal serum phosphate(PSM:HR 1.56,95%CI 1.04-2.30;P < 0.001;PSW:HR2.09,95%CI 1.49-2.93;P < 0.001).The risk of death in patients with hyperphosphatemia increased with blood phosphorus concentration rise.Similar analysis yielded consistent results when using MIMIC database.Conclusion:In critically ill patients,the 28-day mortality risk of patients with hyperphosphatemia was significantly higher than that of patients with normal blood phosphorus,and was proportional to the degree of elevated blood phosphorus.The increase of both the initial blood phosphorus level on admission and the average blood phosphorus level indicate that patients may have poor prognosis.Age,creatinine,SOFA score,hypocalcemia and diabetes are all independent risk factors for hypercalcemia.