A Study Of The Relationship Between Uric Acid Levels And Type 2 Diabetes

Objectives:Uric acid is a by-product of oxidation of purine.Hyperuricemia is a biochemical entity that is gaining increasing importance as it has been found by some researchers to be not only a cardiovascular risk factor but also play a role in the development of renal and metabolic disease.Type 2 diabetes is up to the global health problem now.The effect of uric acid on type 2 diabetes mellitus is still uncertain.In this paper,cross-sectional survey and cohort study methods were used to analyze and verify the effect of uric acid on type 2 diabetes mellitus.1.Through cross-sectional studies to determine the secular trend in Prevalence of diabetes in Chinese adults in Qingdao,China.2.To describe the distribution of uric acid level under different Hb Alc group and explore the correlation between the two.3.To evaluate the performance of uric acid level for type 2 diabetes and abnormal glucose level.4.Estimation of the cumulative incidence of type 2 diabetes mellitus through the analysis of follow-up data.5.Further verify the performance of uric acid level for the risk of type 2 diabetes mellitus.6.Estimates the population attributable risk of risk factors of type 2 diabetes.Design and Methods: 1.First stage: Two cross-sectional diabetes surveys were conducted in three urban areas(Shinan,Shibei and Sifang)and three rural ones(Huangdao,Jiaonan and Jimo)in Qingdao China in 2006 and 2009,respectively.A stratified,random cluster sampling method was used to recruit a representative sample of the general population who had lived in Qingdao city for at least 5 years.A total of 12200 individuals aged 35—74 years attended the 2006 and 2009 survey,with a response rate of 85.78%.The same protocols,questionnaires,physical examination and method of laboratory determination were employed between 2006 and 2009 surveys.People who reported a history of diabetes and underwent treatment with either insulin or oral antidiabetic agents were considered as previously diagnosed diabetes,regardless of their glucose levels.Newly diagnosed diabetes was defined as a Hb A1c?6.5% and/or FPG ?7.0 mmol/L and/or 2h PG?11.1 mmol/L according to the IDF criteria and ADA.For continuous variables,differences between groups were tested using T-test for comparing two groups or,alternatively,one-way ANOVA complemented by the Duncan test.The Chi-square test was employed as categorical variables.Correlations of UA with Hb A1 c were studied with Spearman method.Binary logistic regression analysis was performed to evaluate the association of UA with diabetes and abnormal glucose.Statistical analyses were performed using SPSS(Statistical Package for Social Sciences,USA),version 18.0.P values of <0.05 were considered to be statistically significant.2.Second stage: The study cohort was derived from a source population of 5110 Qingdao adults aged 35—74 years.The cross-sectional survey was initiated in 2009—2010,follow-up evaluation was conducted in 2012—2013.Subject to follow-up study were 2346 people.The actual follow-up of 2312 people,the loss rate of 3.33%,the final 2177 were included in this study.The same protocols,questionnaires,physical examination and method of laboratory determination were employed cohor and cross-sectional survey.In the current study,the definition of hyperuricemia was based on the Sixth Edition Department of Internal Medicine criteria(UA > 420?mol/L for men,UA > 350?mol/L for women).Newly diagnosed diabetes was defined as a Hb A1c?6.5% and/or FPG?7.0 mmol/L and/or 2h PG ?11.1 mmol/L according to the IDF criteria and ADA.After stratified by sex and age,the incidence of diabetes mellitus and the prevalence of hyperuricemia were calculated.The association between different uric acid levels and risk of diabetes were estimated by logistic regression mode then estimated the population attributable risk.Results:1.The prevalence of diabete and prediabete in study area was 17.3%?30.7%(the standardized prevalence rate was 17.06%?30.65%)respectively,and prevalence did not differ between men and women(P>0.05).Diabete and prediabete prevalence rate of the urban was 19.3% and 30.9%,the rate of the rural was 15.7% and 30.7%.There were significant differences of diabete(P<0.01)prevalence among urban and ruralpeople but prediabete(P>0.05)The prevalence of diabetes(P<0.01)raised with age and There were significant differences of prediabete(P<0.01)among different group of age.2.During the follow-up period of 3 years,there were 208 cases of diabetes,and the cumulative incidence rate was 9.55%.Among them,88 cases were male and 120 were female.Cumulative incidence rates were 10.98% and 8.73%,respectively.Overall,the cumulative incidence of diabetes showed an upward trend with age(P<0.01).Smokers,diabetes family history,hypertension and dyslipidemia of cumulative incidence rate was higher(P<0.05).3.Whether male or female,the serum UA levels increased with moderately increasing levels of Hb A1c(Hb A1c<6.5%)and then decreased with further increasing levels of Hb A1 c.Correlation analysis showed that there was a negative correlation between uric acid and Hb A1 c in patients diagnosed with diabetes mellitus,and there was no linear relationship between the two groups in unkown diabetes group.Multi factor non conditional logistic regression analysis was performed with Hb A1 c as the diagnostic criteria.The second points of uric acid had the highest adjusted odds ratio(OR=4.088).4.High serum UA level was independently associated with a high risk of diabetes and abnormal blood glucose.Binary adjustment for various potential confounders did not alter the UA–glucose association substantially although the regression coefficients have been reduced in some of the models.The OR(95% CI)for prevalence of type 2 diabetes were Q3:1.397(1.139-1.714),Q4:1.459(1.185-1.798)after adjusting three models.Abnormal blood glucose was Q4:1.268(1.104-1.455)after adjusting four models.5.Hyperuricemia patients with type 2 diabetes risk is 1.497 times than the normal level of uric acid.The multiple factors adjusted population attributable risk for incident diabetes attributable to hyperuricemia was 6.71%.Conclusions:The prevalence of diabete in study area hed higher level in the nationwide but prediabete was lower.Higher level of SUA is positively and significantly associated with diabete and abnormal blood glucose.If the risk factor for hyperuricemia is removed,then 6.71% of diabetes can be prevented.