The Relationship Between Serum Uric Acid And Renal Damage Among Patients With Type2Diabetes Mellitus

Objective: With the economic development and the improvement ofpeople’s living standards in China, type2diabetes mellitus (T2DM) hasbecome a prevalent disease that threatens public health. Its chroniccomplications can widely injure all tissues and organs. Microangiopathy is thespecial pathological change of T2DM while diabetic nephropathy(DN) is oneof the most important. DN is the leading cause of end-stage renal failure andone of the most important reasons that lead to diabetic patients’ death ordisability. As an early biochemical marker and independent risk factor ofT2DM[1], serum uric acid(SUA) can promote the happening of DN togetherwith metabolic syndrome. Previous clinical studies pay more attention to thecorrelation between hyperuricemia(HUA) and DM or DN, but less attention tothe SUA when it runs within the normal range.The purpose of the study is to compare general clinical andkidney-related index of patients with T2DM of different SUA levels to analyzethe relationship and correlation intensity, thus providing new theoretical basisfor the prevention, early diagnosis and treatment of DN. The indexes includeage, duration of diabetes(DUR), systolic blood pressure(SBP), diastolic bloodpressure(DBP), glycosylated hemoglobin(HbA1c), fasting plasmaglucose(FPG), insulin sensitivity index(ISI), body mass index(BMI), totalcholesterol(TC), triglyceride(TG), high density lipoproteincholesterol(HDL-C), low density lipoprotein cholesterol(LDL-C), SUA, serumcreatinine(SCr), blood urea nitrogen(BUN),24hour urinary albumin.Methods:102cases of T2DM patients who were hospitalized fromFebruary2012to November2012at the department of Endocrinology, theThird Hospital of Hebei Medical University were randomized, of which76were males and26were females. The diagnosis of DM is based on the criteria of the WHO(1999). All the patients were measured and recorded in terms ofHeight, Weight, SBP, DBP, calculated BMI on the same day they admitted tothe hospital, and with their medical histories consulted. The next morning,overnight fasting(fasting≥8h) venous blood were extracted to test TC, TG,HDL-C, LDL-C, SUA, SCr, BUN, fasting insulin(FI).24hour urine werecontinuously collected with the absence of severe exercise state to detect24hour urinary albumin.24hour urinary albumin less than30mg was noalbuminuria,24hour urinary albumin between30mg to300mg wasmicroalbuminuria, while more than300mg was macroalbuminuria.Anthropometry indexes and blood pressure were measured by standardmethods, clinical biochemical index determination and quality control werecompleted in our hospital. Patients were divided into four groups named groupA, group B, group C, group D on the basis of SUA level according tointer-quartile range. We compared the data of the four groups. Normaldistribution quantitative data were expressed as means±s. Non-normaldistribution quantitative data were expressed as median(inter-quartile range),Associations between the groups were examined using the analysis of χ2test.One-way analysis of variance was used for multigroup comparison which didconform to the normality and homoscedasticity while non-parametric test wasused which did not conform to the normality or homoscedasticity. Correlationanalysis was used for univariate analysis, and multiple regression analysis formultivariate analysis. Statistical analyses were done by SPSS Software (V13.0,SPSS Inc., USA). inspection level was α equal to0.05, p value <0.05wasconsidered statistically significant.Results:1Comparison of general clinical index BMI and TG increased with theincreasing of SUA, and the difference was statistically significant(p＜0.05)；when it came to the age, duration of diabetes, HbA1c, SBP, DBP, TC, HDL-C,LDL-C and ISI, there were no statistically significant differences between thefour groups(p＞0.05).2Comparison of kidney related index24hour urinary albumin increased with the increasing of SUA. The prevalence of microalbuminuria inthese four groups were group A28.0%, group B34.6%, group C61.5%, groupD44.0%; and the difference was statistically significant(p＜0.05); Whencomparing the two, there was no statistically significant differences betweengroup A and group B(p＞0.05), but statistically significant between group Aand group C, group A and group D(p＜0.05). It is indicated that early renaldamage of diabetes has increasing trend with the increasing of serum uric acidconcentration when serum uric acid concentration has not reachedhyperuricemia level. Besides, serum creatinine and blood urea nitrogenincrease with the increasing of SUA, and the difference is statisticallysignificant(p＜0.05).3The correlation between24hour urinary albumin and metabolic indexMultiple stepwise regression analysis showed that SUA, age and ISI wereassociated with urinary albumin and the standardized regression coefficientwere0.518,0.365,0.180，meaning that SUA had the most significant effectson urinary albumin.4Spearson correlation analysis showed that the duration of diabetic andSBP were also associated with24hour urinary albumin. SUA was associatedwith FPG, BUN, Cr, BMI and TG in the multivariate stepwise analysis whenSUA was the dependent variable.Conclusions:1Among the factors associated with DN, SUA had the most significanteffect. Moreover, early renal damage of diabetes mellitus have increasingtrend with the increasing of SUA concentration while serum uric acidconcentration had not reached hyperuricemia level. Therefore the monitoringof SUA concentration was of great significance in preventing early diabetickidney damage, early diagnosis and treatment.2Hypertension, obesity and IR were the the influential factors of DN，meanwhile they are closely related to HUA and accelerate the occurrence anddevelopment of DN together.