Levels Of25(OH)D And Related Factors In Patients With Chronic Kidney Disease

Objective: Chronic kidney disease(CKD) is a common disease that isseriously harm to human health, and is associated with a substantial burden ofmorbidity, mortality and health care costs, the number of patients with CKD inChina is estimated to be about119.5per million population, how to delay theprogression of CKD has become a clinical research hotspot. People graduallyhas been concerned about renoprotective effects of active vitamin D in CKDpatients. Vitamin D is an inherent steroid hormone, which active form hasanti-proliferative, anti-differentiation, regulation of apoptosis, mediatedimmune response and multiple endocrine hormone secretion. Now generallyaccepted the clinical evaluation index of vitamin D was25-hydroxyvitaminD(25(OH)D), which is he most abundant and most stable vitamin Dmetabolite in the circulation, its biological half-life is about3weeks, testingcan be used as the effective indicator of vitamin D nutritional status in thebody.25(OH)D in patients with chronic kidney disease is also associated withcardiovascular disease, and even affect the prognosis of CKD population toend-stage renal disease or death. The kidney is the key organ involved in thesynthesis of vitamin D, vitamin D deficiency is often associated with chronickidney disease, and its prevalence increases related to renal function declines.Emerging evidence that active vitamin D can prevent the progression ofchronic kidney disease. Therefore, the early monitoring of serum25(OH)Dlevels in patients with CKD to assess disease trends, outcomes and theoverall prognosis is of great significance. This paper aims to investigate thesituation of25(OH)D insufficiency and deficiency in non-dialysis chronickidney disease patients, as well as to analyze the relevant factors, explore themechanism of active vitamin D in the progression of CKD.Methods: The study was approved by the department of Nephrology, the second hospital of Hebei Medical University. We chosen114cases(64malesand50females, mean age45.74±15.11years) diagnosed chronic kidneydisease without renal replacement therapy from November2012to August2013. Exclusion criteria included the following:(1) patients with severe skindisease;(2) cirrhosis or other causes hepatic insufficiency;(3) the primaryosteoporosis;(4) pre-selected applications within a month had active vitaminD and its analogues, calcitonin and other medicine;(5) within the past threemonths used glucocorticoid and immunosuppressive agents;(6) receivedparathyroidectomy;(7) malignant tumor, persistent diarrhea, chronic infectio-ns, autoimmune diseases and other diseases. According to the National KidneyFoundation-Kidney Disease Outcomes Quality Initiative(NKF-K/DOQI)guidelines definition of chronic kidney disease in2005:(1) renal injurysustained three months, kidney damage refers to structural or functionalabnormalities, with or without glomerular filtration rate(GFR) decreases, asone of the following: pathologic abnormalities or renal damage indicator(including abnormal blood or urine components) or radiographic abnormalities;(2) GFR<60ml/min/1.73m2last three months, with or without kidney damage.CKD stages:1: GFR≥90ml/min/1.73m2;2: GFR60~89ml/min/1.73m2;3: GFR30~59ml/min/1.73m2;4:GFR15~29ml/min/1.73m2;5:GFR<15ml/min/1.73m2.eGFR was estimated according to CKD-EPI formula. Divided into threegroups according to eGFR levels: T0group is CKD1~2stages, T1group isCKD3stages, T2group is CKD4~5stages. Vitamin D levels diagnosticcriteria: vitamin D sufficiency, insufficiency, and deficiency as levels of>30ng/mL,21to29ng/mL, and <20ng/mL, respectively. In accordance with25(OH)D levels were divided into two groups:25(OH)D≥20ng/mL group and25(OH)D<20ng/mL group. The serum level of25(OH)D was detected byelectro chemiluminescence(ECLI) method. Clinical parameters included age,gender, height, weight, primary disease, blood pressure, serum creatinine(Scr),albumin(ALB), uric acid(UA), total cholesterol(TC), triglyceride(TG), lowdensity lipoprotein-C(LDL-C), high density lipoprotein-C(HDL-C), estimateglomerular filtration rate(eGFR),24-hour urinary protein quantitative (24h UPro), intact parathyroid hormone(iPTH). Factors associated with25(OH)Dwere evaluated by using Pearson correlation analysis, the independent factorscorrelated with the level of25(OH)D were estimated by multiple linearstepwise regression analysis. P<0.05was considered statistically significant.Body mass index (BMI) was calculated as weight (kg)/height2(m2).Results:1The clinical datum of patients with CKD: T0group of48cases,32males and16females; T1group of30cases,12males and18females; T2group of36cases,20males and16females. Between T0, T1and T2groups,the age, gender and BMI were no significant differences(P>0.05), systolicblood pressure, diastolic blood pressure, ALB, UA, iPTH in T2group werehigher than those in T0and T1groups, respectively(P<0.05), at the same time,eGFR and25(OH)D are more lower than T0and T1groups(P<0.001). Theprimary disease: primary glomerulopathy in46.49%of the patients, diabeticnephropathy in18.42%, hepatitis B virus associated glomerulonephritis in16.67%, hypertension nephropathy in11.40%, Hen ch Sch nlein purpuranephritis in4.39%, polycystic kidney disease in2.63%.225(OH)D levels in CKD patients: the mean level of25(OH)D was(21.96±5.34)ng/mL, the prevalence of25(OH)D insufficiency accountedfor44.74%(51/114), deficiency accounted for50.00%(57/114), sufficiencyonly accounted for5.26%(6/114). The incidence of vitamin D deficiencyamong the three groups was statistical significance (P<0.05).3The index characters in different levels of25(OH)D: Between25(OH)D≥20ng/mL group and25(OH)D<20ng/mL group, age, gender, diastolic bloodpressure, TG, HDL-C, UA had no significant difference(P>0.05), while BMI,systolic blood pressure,24-hour urinary protein quantitative,TC, LDL-C in25(OH)D<20ng/mL group were increased(P<0.05), ALB, eGFR were decrea-sed(P<0.05).4Correlation analysis: Serum25(OH)D level and CKD patients’ age,gender, diastolic blood pressure, UA were not related(P>0.05), with BMI, SBP,24hUPro, TC, TG, LDL-C, iPTH, Scr in CKD patients showed a negative correlation(r=-0.037, r=-0.323, r=-0.387, r=-0.314, r=-0.338, r=-0.558,r=-0.774, r=-0.741, P<0.05), with ALB, HDL-C, eGFR showed a positivecorrelation(r=0.405, r=0.638, r=0.798, P<0.05). Multivariate stepwiseregression analysis demonstrated that LDL-C, eGFR were the independentfactors affecting serum25(OH)D level, the regression equation=16.50+0.109eGFR–0.966LDL-C.Conclusions:125(OH)D insufficiency and deficiency was very common innon-dialysis CKD patients, and25(OH)D deficiency with progression of renalfunction was more obvious from CKD3stage.2Serum25(OH)D levels and BMI, SBP,24hUPro, TC, TG, LDL-C,iPTH, Scr had a negative correlation, with ALB, HDL-C, eGFR had a positivecorrelation in CKD patients, LDL-C, eGFR were the independent factorsaffecting serum25(OH)D level in CKD patients.