Effects Of Vitamin D On Renal Anemia In Patients Undergoing Chronic Kidney Disease:a Meta-analysis

Background The prevalence of vitamin D deficiency in patients is high,especially in patients undergoing Chronic kidney disease.With the decline of renal function and the progression of CKD,the morbidity of vitamin D deficiency and anemia is increasing.Recently years,the study has found that vitamin D have the unique function of improving the anemia of CKD.Some clinical randomized controlled studies have shown that vitamin D supplementation can significantly improve renal anemia or reduce the application of erythropoietin,but in recent randomized controlled studies did not achieve significant clinical efficacy.To this end,we reviewed a large number of studies on the effects of vitamin D on renal anemia,and further conduct a Meta-Analysis to evaluate the effect of vitamin D supplementation on the clinical efficacy of renal anemia in patients with chronic kidney disease,in order to provide guidance for treatment of renal anemia.Objective This study based on the domestic and foreign studies about vitamin D supplement in patients with chronic kidney disease(CKD)patients with renal anemia,conducted a meta-analysis of clinical randomized controlled studies,exploring the clinical curative effect of vitamin D supplements in combination with erythropoietin for the treatment of chronic kidney disease(CKD)patients with renal anemia.Methods/design We will conduct a meta-analysis about the effects of Vitamin D on Renal anemia in patients undergoing Chronic kidney disease according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines.The primary objective is to assess the change of hemoglobin and the dosage of erythropoietin.Secondary outcomes will include the inflammatory state,hyperparathyroidism,the concentration changes of calcium and phosphate,and iron metabolism related indicators,etc.We will search all the Chinese and English databases of PUBMED,MEDLINE,EMBASE database,Web of Science,Cochrane Clinical Library,CNKI,WanFang VIP,and CBM from the start of the database to January 2018.Clinical randomized controlled trials were selected,which conforms to the standard of inclusion and exclusion preset.Information were extracted from the inclusion of the standard data.The content of the extraction includes:the author of the data,publication time,stochastic method,the basic information of the object of the study,intervention used,dose,course of treatment,the observation target of the outcome.The Cochrane Risk Assessment Tool will be used to assess the quality of eligible studies and the software Revman5.3 was used to analyze the extracted information through Meta-analysis.Results A total of 12 clinical randomized controlled studies were included in this meta-analysis,with a total of 739 patients,including 363 patients in the experimental group and 376 patients in the controlled group.This meta-analysis showed that Vitamin D supplementation can increase the hemoglobin level significantly in patients with chronic kidney disease.[P<0.00001,SMD=1.24,95%CI(1.02,1.45)];Can decrease the dose of erythropoietin.[P<0.00001,SMD=-0.76,95%CI(-1.09,-0.43)].However there no statistical difference of blood calcium[P=0.10,SMD=0.15,95%CI(-0.03,0.32)],blood phosphorus[P=0.17,SMD=-0.12,95%CI(-0.29,0.05)],Ferritin[P=0.51,SMD=-0.07,95%CI(-0.26,0.13)],transferrin saturation[P=0.95,SMD=0.05,95%CI(-1.63,1.73)],and no statistical difference of CRP[P=0.41,SMD=0.08,95%CI(-0.11,,0.28)].Conclusion The meta-analysis results showed that vitamin D supplements compared with control group could significantly increased hemoglobin concentration compared with control group,reduced the dosage of erythropoietin,and improved erythropoietin resistance.There was no negative effect on PTH,serum calcium and phosphorus plasma.There was no significant effect on iron metabolism index and inflammatory state of ferritin and transferrin saturation.Owing to the differences among patients chosen by randomized clinical controlled trials and differences in the application of Vitamin D in dose and course of treatment.The conclusion remains to be verified by large-scale,multicenter,and prospective randomized controlled trials.