Study Of The 1-h Postload Glucose During An Oral Glucose Tolerance Test And The First-phase Insulin Secretion In Gouty And Hyperuricemic Patients With Normal Glucose Tolerance

OBJECTIVE:To investigate whether there is any difference of pancreatic βcells function in gouty and hyperuricemic patients with normal glucose tolerance(NGT)when 1-h postload glucose(1hPG)was>8.6mmol/L and<8.6mmol/L during an oral glucose tolerance test(OGTT),especially the change in the first-phase insulin secretion.So that we can determine whether the 1-h postload hyperglycemia is a good indicator for the future onset of diabetes in gouty and hyperuricemic patients with NGT,and then we could diagnose and take interventions earlier to prevent or defer the diabetes occurrence.METHODS:A total of 143 in-patients or out-patients containing 112 males and 31 females with gout or hyperuricemia who visited the First Affiliated Hospital of Guangxi Medical University from January,2009 to Mach,2015 were selected.According to the results of OGTT,the subjects were divided into 3 groups:type 2 diabetes group(T2DM group,consist of 36 males and 7 females,mean age was 52.3±12.7 years),impaired glucose regulation group(IGR group,consist of 32 males and 13 females,mean age was 44.2±15.0 years)and NGT group.Moreover,a cut point of 8.6mmol/L in OGTT 1hPG was used to sub-divide the NGT patients into two subgroups:1hPG ≥8.6mmol/L group(NGT1 group,consist of 23 males and 7 females,mean age was 39.3±15.4 years),1hPG<8.6mmol/L group(NGT2 group,consist of 21 males and 4 females,mean age was 37.4±15.0 years).All the clinical data including sex,age,the course of disease,height,weight,blood pressure,blood lipid,renal function test,glycosylated hemoglobin(HbAlc)were collected and the intravenous glucose tolerance test(IVGTT)was performed in every research object.Homeostasis model assessment of insulin resistance(HOMA-IR)was used to assess the insulin resistance.The acute phase of insulin secretion(AIR)and the area under the curve of insulin(AUCinsn-10min)in IVGTT were used to assess first-phase insulin secretion.AUCins0-3h and the ratio of AUCins0-3h to the area under the curve of glucose(AUCglu0-3h)(AUCins/AUCglu0-3h]of OGTT were used to assess the second-phase insulin secretion.Together with the homeostasis model assessment of insulin secretion(HOMA-β),modified beta cell function index(MBCI),Ip,Ip/I0 in OGTT and IVGTT were used to assess the pancreatic βcells function.The bivariate correlation analysis were used to explore the relationship between serum uric acid(SUA)and 1hPG.RESULTS:1.In DM2 and IGR groups,the proportion of patients whose gouty or hypereuicemic course longer than dysglycemia were 44.2%,46.7%respectively.44.8%patients who were found dysglycemia in this health seeking,were diagnosed by fasting blood glucose and postprandial blood glucose in regular meals,the other 55.2%were diagnosed by OGTT.2.In OGTT,the peak of insulin secretion curve in IGR group was delayed,while the insulin secretion curves were similar between NGT1 and NGT2 groups.There were also no statistical difference in Ip/I0,HOMA-IR,HOMA-P,AUCins/AUCglu0-3h,AUCins0-3h among IGR,NGT1 and NGT2 groups(P>0.05).It meant there were no difference in second-phase insulin secretion among these 3 groups.3.Similar to IGR group,NGT1 group had a apparent fall in first-phase insulin secretion.In IVGTT,AIR,AUCins and Ip/I0 were not significantly diferent between IGR and NGT1 groups(P>0.05),but these indicators were obviously decreased in both groups when compared with NGT2(P<0.05).3.The MBCI can be used to distinguish the difference of insulin secretion faction between IGR and NGT patients.The MBCI gradually decreased in IGR,NGT1and NGT2 groups(P<0.05).4.SUA were positively correlated with 1hPG among IGR,NGT1 and NGT2 groups(the correlation coefficients were 0.457,0.486,0.503 respectively,P<0.05),but this correlation was not seen in T2DM group(the correlation coefficient is-0.040,P>0.05).CONCLUSIONS:1.OGTT examination in patients with gout and HUA can increase 55.2%the detection rate of dysglycemia,reduce missed diagnosis.2.There are positive correlation between SUA and lhPG before the onset of diabetes in gouty and hyperuriceic patients.It is likely that 1hPG has already increased when the SUA level was obviously high.Similar to gouty and hyperuricemic patients with IGR,first phase insulin secretory defect was appeared in patients with NGT when OGTT 1hPG ≥8.6mmol/L.Exist,They are at high risk for diabetes,so we should take earlier interventions to prevent or defer the diabetes occurrence.3.MBCI can sensitively be used to distinguish the difference of pancreatic β cells function in both IGR and NGT patients.As IVGTT is a high-skilled performance,we can use the MBCI of OGTT to earlier evaluate the impairment of pancreatic P cells function in clinical practice.