Effects Of Dietary Factors On Hyperuricemia And Metabolic Syndrome

Objective1.Our present study aimed to examine the association of serum uric acid and incident MS during the 3-year follow-up by using the Chinese Diabetes Society(CDS)and further to determined the optimal cut-off value of serum uric acid for diagnosis of MS.2.To analyze the associations of dietary factors and HUA and MS by combination of the factor analysis(FA)with traditional food analysis,and further to evaluate the effects of dietary intervention on HUA and MS patients to clarify the associations of diet and HUA and MS.3.Our aim was to analyze the changes of metabolites which were due to dietary factors in HUA and MS patients by metabonomics and explore some specific markers of metabolic disorders,for the purpose of preventing and controlling the occurrence and development of HUA and MS.Methods1.At baseline,those with MS were excluded according to the diagnostic criteria for MS(CDS)and then we observed the incidence of MS in HUA group and non-HUA group during the 3-year follow-up.Cox regression analysis was used to assess the hazard ratios in HUA group and non-HUA group.Receiver operating characteristic(ROC)curves was used to compare the predictability of the baseline SUA on the future development of MS.The diagnostic cutoffs of serum uric acid for future MS were defined by the values with the highest accuracy that maximized the Youden's index.2.Baseline survey was conducted among HUA group,MS group,HUA accompanied by MS group and control group,which were selected randomly from the health check-up population,including medical examination,life behavior and food frequency questionnaire(FFQ)investigation,for the purpose of exploring the dietary protective or risk factors for HUA and MS.Then the patients in HUA group,MS group,HUA accompanied by MS group were divided randomly into quantitative dietary intervention group and general dietary intervention group for three months.After 3-months intervention,the effects of dietary intervention in each group were evaluated and the effects of different dietary intervention ways were also compared in each group.3.NMR spectra of the plasma samples were acquired ona Varian INOVA 600MHz NMR spectrometer by using Carr-Purcell-Meiboom-Gill and bipolar pulse pair-longitudinal eddy current delay pulse sequence.All plasma spectra were manually phased and baseline corrected.The Excel format of data was imported into SIMCA-P(v10.04,Umetrics,Umea,Sweden)for multivariate analysis.Average data using centralized(mean centering)or Pareto scale(Pareto scaling)after pretreatment by using principal components analysis(PCA).Due to large differences of within-group affected by various factors,orthogonal signal correction(OSC)was used to preprocess the data first,then to use partial least square(PLS)analysis.Finally,exploring the metabolites accrording to the scores plots and loadings plots to identify biomarkers and trace its source and metabolic pathways.Results1.According to the CDS cretiria for diagnosis of MS,a total of 8157 adults free of MS were followed for 3 years.During the 3-year follow-up,1215 individuals developed MS.Compared with the non-HU A group,the risk for MS in HU A group were 1.183 times and 1.557 times in men and women,respectively after adjusting the associated variables.Particularity,compared with the bottom quartile,the risk of MS in the top quartile of serum uric acid levels were 1.444 times(P<0.05)in men and 1.926 times(P<0.05)in women.The optimal cut-off values for serum uric acid to identify MS were 374?mol/L in men and 297?mol/L in women,respectively.2.Traditional food analysis concluded that the intake of anima foods,including pork,beef and mutton,animal giblets,eggs and fried foods were positively correlated with the incidence of HUA,HUA accompanied by MS(P for trend test<0.05);intake of pure energy foods(cakes,drinks and alcohol)were positively correlated with the incidence of MS,HUA accompanied by MS(P for trend test<0.05);intake of fruits,vegetables,dairy products,soybean products and nuts were negatively correlated with the incidence of HUA,MS,HUA accompanied by MS(P for trend test<0.05).Through principal component analysis,three major dietary patterns were animal products-fried food pattern,western dietary pattern and soybean products-fruit pattern.After adjusting the relevant variables,the occurrence of HUA was related with animal products-fried food pattern and soybean products-fruit pattern;the occurrence of MS was related with western pattern and soybean products-fruit pattern;the occurrence of HUA accompanied by MS was related with animal products-fried food pattern,western pattern and soybean products-fruit pattern.The serum uric acid in HUA group,MS group and HUA accompanied by MS group were decreased significantly after dietary intervention(P<0.05).At the same time,compared with baseline,the TG levels in these three groups were lower than baseline(P<0.05),HDL-C were higher than baseline(P<0.05).But there were no statistical differences in the effects of different dietary intervention on serum uric acid and the other medical indicators(P>0.05)in each group.3.There were differences in medical indices among control group,HU A group,MS group and HUA accompanied by MS group.Howerver,there was no statistical significant in food intake among these four groups(P>0.05).Principal component analysis model showed that the metabolomics data could separate HUA,MS,HUA accompanied by MS patients completely,it was observed the clustering clearly and approximation separation between HUA patient and the HUA accompanied by MS patient,and there was a trend of transition of HUA patients to HUA accompied by MS patients.From score plot and loading plot of the OSC-PLS model,there was the existence of differences in metabolites among the four groups.Through the establishment of the pairwise comparison of the OSC-PLS model,it was observed that the difference about the content of metabolites was not only between three groups and control group,but also among these three groups.Compared with control group,HUA patients had a higher concentration of low density lipoprotein(LDL).very low density lipoprotein(VLDL),low density lipoprotein/very low density lipoprotein(LDL/VLDL),glutamic acid/N-acetyl-glycoprotein,lactic acid,lactic acid/threonine,saturated fatty acids and unsaturated fatty acids and a lower concentration of glutamine,valine,glutamine/glutamate,creatine,phosphatidyl choline,glycine/glucose and the glucose in plasma.Compared with control group,MS patients had a higher concentration of LDL,VLDL,LDL/VLDL,glucose,saturated fatty acids and unsaturated fatty acids and a lower concentration of leucine/isoleucine,valley amide,valine,glutamine/glutamic acid,phosphatidyl choline,lactic acid/threonine and alanine in plasma.Compared with control group,HUA accompanied by MS patients had a higher concentration of LDL,VLDL,glutamic acid/N-acetyl-glycoprotein,LDL/VLDL,lactic acid,lactic acid/threonine,saturated fatty acids and unsaturated fatty acids and a lower concentration of glutamine,valine,glutamine/glutamate,phosphatidyl choline,glycine/dextrose,glucose and alanine in plasma.Compared with HUA accompanied by MS patients,HUA patients had a higher concentration of leucine/isoleucine,glutamine,valine,glucose,lactic acid,alanine,and the ethanol in plasma.Compared with HUA accompanied by MS patients,the concentration of glucose was relatively high in plasma.ConclusionSerum uric acid levels can predict the occurrence of MS,which may be a new index to combine the other related indicators for diagnosis of MS.Dietary factors were associated with HU A and MS.Thus lowering serum uric acid level through dietary intervention could prevent the occurrence of MS.Metabonomics technology revealed that the changes of metabolites in HUA and MS patients might be caused by pathological state rather than the role of dietary factors.And the possible potential biomarkers of hyperuricemia developed to hyperuricemia accompanied by metabolic syndrome were LDL,VLDL,phosphatidyl choline,leucine/isoleucine and alanine.