Clinical Investigation Of Serum25-hydroxyvitamin D₃in Patients With Type2Diabetes Mellitus And Diabetic Nephropathy

Diabetes is a metabolic disorder characterized by hyperglycemia. Asone of the most common chronic diseases, the prevalence of diabetes isincreasing in recent years, in which more than90%are type2diabetesmellitus. Diabetic nephropathy is one of the most common microvascularcomplications of type2diabetes. In China, End-stage renal disease（ESRD） caused by DN accounted for about8%of all ESDR, evenreached15%in some areas. DN has seriously affected patient’s quality oflife, and even threaten their life. Therefore, early detection, earlydiagnosis and early treatment are essential to the DN.Objective: By systematic analyzing the common clinical indexesin patients with type2diabetes and diabetic nephropathy, we explored therelationship between serum25-hydroxyvitamin D₃level and urinaryalbumin/creatinine ratio inpatients with type2diabetes and varyingdegrees of diabetic nephropathy. So as to provide a theoretical basis forfinding DN indicators with higher specificity and sensitivity. So thatclinicians can give early diagnosis and treatment to the patients, andimprove their life quality.Materials and Methods：The research data were selected fromendocrinology and metabolism department of First Bethune Hospital ofJilin University from April2012to January2013. There were56patientswho were diagnosed of type2diabetes and diabetic nephropathy at thetime of discharge. Twenty healthy adults with matched age and sex wereselected in hospital examination center at the same period as the normal control. All patients met the diagnostic criteria of World HealthOrganization （WHO） in1999on T₂DM. According to the AmericanDiabetes Association （the American Diabetes Association, ADA）recommended urinary albumin creatinine ratio （ACR）（<30mg/g,30of300mg/g,>300mg/g）, we divided all the research objects intonormal albuminuria group （group B）, microalbuminuria group （group C）and macroalbuminuria group（group D）. Exclusion criteria:（1） Patientswith other kidney diseases except for DN.（2） Chronic liver injury.（3）Urinary tract infection.（4） Malignancies.（5） Suffered from acute diseasesrecently.（6） Taking drugs which affecting bone metabolism in the past sixmonths.（7） Osteoporosis, other endocrine diseases and autoimmunediseases. Use Roche electrochemical detection to test serum25-（OH）D₃,other indicators were tested by chemiluminescence detection. Kitsprovided by Beckman Coulter. Choose ACCESS chemiluminescenceanalyzer produced by the company as the detected equipment.Research methods: Urinary albumin/creatinine ratio （ACR）,serum25-hydroxyvitamin D₃（25-（OH）D₃）, hemoglobin A1c （HbA1c）,fasting plasma glucose （FPG）, triglycerides （TG）, total cholesterol （TC）,high-density lipoprotein cholesterol （HDL-C）, low-density lipoproteincholesterol （LDL-C）, serum creatinine （CRE）, blood urea nitrogen （BUN）,albumin （Alb）, blood uric acid （UA） and γ-glutamyl transpeptidase（γ-GT）. Measure all the objects’ height, weight, and calculate body massindex （BMI）[=body weight （kg）/height （m2）]. Statistical Methods:Independent samples t test were used to analyze the various indicators ofgender differences. Using single factor analysis of variance to analyze thedifferences of indexes among the four groups. Choose Pearson correlationanalysis to analyze the correlation between25-（OH）D₃and otherindicators. Use multiple liner regression analysis to analyze the influencing factors of25-（OH）D₃. Apply SPSS16.0software for statisticalanalysis.Results：（1）There existed significant gender differences （p<0.01） ofserum25-（OH）D₃, men were higher than women.（2） Compared with thecontrol group, all56cases of DM patients’ HbA1c, FPG,25-（OH）D₃, TG,LDL-C and BUN levels were higher than the former, and the differenceswere statistically significant （p<0.001）. The different levels of ACR in allthe DM groups were statistically significant（p<0.001）. Compared with thecontrol group, serum25-（OH） D₃levels in each experimental group weresignificantly lower （p<0.001）, particularly in group D. However, thesignificance between group B and group C was not so evidently. Thelevels of serum25-（OH）D₃between group C and group D in both maleand female showed no significant difference. Uric acid level hadsignificantly increased（p<0.001） in group D, compared to the others. Thelatter groups showed no significant difference when suffered frompairwise comparisons.（3） There was significantly negative correlations （p<0.01） between T₂DM patients’ serum25-（OH）D₃and age, diseaseduration, ACR, TG, BUN, CRE and uric acid, while the Alb presence ofsignificant with the positive related （p <0.01）.（4） Age, ACR and TG hada significant negative prediction to serum25-（OH） D₃levels in patientswith T₂DM （p <0.05）.Conclusions：（1）The level of serum25-hydroxyvitamin D₃hadgender correlation, which was lower in women than in men.（2）Serum25-hydroxyvitamin D₃level in patients with T₂DM compared to normal oneswas decreased.（3）Serum25-hydroxyvitamin D₃level in patients withclinical diabetic nephropathy was lower than patients with early diabetesnephropathy.（4）Age, urinary protein/creatinine ratio, and triglycerideswere the negative predictor of serum25-hydroxyvitamin D₃in type2 diabetes mellitus.