An Analysis Of The Insulin Resistance And Islet Beta-cell Function In Patients With Type2Diabetes With Different Course Of Disease

0bjectiveThe aim of this study was to evaluate the insulin resistance and isletbeta cell function among patients with type2diabetes mellitus with differentstages of the disease. The quantitative indices included Homa-insulinresistance(INS or CP), Homa-beta (INS or CP), Modified beta cell functionindex（MBCI=FINS×FPG/（2hPG+1hPG-2FPG)）, acute insulin release (AIR),ΔI30/ΔG30(orΔCP30/ΔG30) and INS-AUC/G-AUC（or CP-AUC/G-AUC）.In this way, these indices were evaluated whether and how to be influenced bydifferent stages of the disease, BMI, ages and glycosylated hemoglobin levels.MethodsThe study comprised315patients with type2diabetes mellitus whowere recruited from March to October2013in the Endocrinology of the FirstAffiliated Hospital of Guangxi Medical University. All the patients were dividedinto sub-group as below. According to the courses of the disease,the patientswere divided into6groups, newly diagnosed group, under one year group,1to5years group,5to10years group,10to15years group and more than15yearsgroup. According to body mass index(BMI), patients were divided into3groups, normal weight group(18.5≤BMI＜24), overweight group (24≤BMI＜28) andobese group（BMI≥28). According to the age，patients were divided into3groups, aged equal to or less than50years group,50-60years group and equalto or older than60years group. According to glycosylatedhemoglobin(HbA1c,%) levels, patients were divided into4groups, HbA1c lessthan7%group，7%-9%group,9%-11%group and more than11%group.Insulin resistance index Homa-IR (INS or CP) was used to evaluate insulinsensitivity and Homa-beta (INS or CP), MBCI, AIR, Δ I30/Δ G30(or ΔCP30/Δ G30),INS-AUC/G-AUC（or CP-AUC/G-AUC）were used to assessislet beta cells secretory function. Comparison was performed among groups asdescribed above towards the insulin sensitivity and islet beta cells secretoryfunction.Results(1) Islet beta cells secretion function was significantly declined(allP<0.01) in patients with disease course more than15years compared to thosewith disease course less than10years for Homa-β（CP）,ΔCP30/ΔG30andCP-AUC/G-AUC, but being similar compared to those with disease course10-15years for all above parameters.(2)Obesity could aggravate insulin resistance and insulin secretion compensatedincreased with BMI. In both overweight group and obese group there werehigher than that of normal weight group for Homa-IR (CP)(P<0.05), Homa-β（INS）(P<0.05), CP-AUC/G-AUC(P<0.01),INS-AUC/G-AUC(P<0.01).(3) Insulin resistance was not affected by the levels of different HbA1c.Beta cell function declined with the increased levels of HbA1c shown in groups withHbA1c>7.0%compared to that in HbA1c <7.0%group for ΔCP30/ΔG30andCP-AUC/G-AUC(all P<0.01).In both HbA1c9%-11%group and HbA1c>11%group there were sharply declined forΔCP30/ΔG30and CP-AUC/G-AUC thanthat in HbA1c7%-9%group(all P<0.05).(4) Insulin resistance and beta cell function didn’t shown changes with age.Conclusion:1.The islet beta cell function was significantly declined in type2diabetesmellitus patients with disease course more than10years.2. Both insulin resistance and beta cell secretion increased with body massindex but not with age.3. Beta cell function could be profoundly impacted by chronichyperglycemia.