The Effect Of Chronic Intermittent Hypoxia And High-fat-feeding On The Islet β Cell Function Of Rabbits

Objective To investigate the effects of chronic intermittent hypoxia (CIH) and high-fat-feeding on the isletβcell function,and analyse the synergistic effect between CIH and high-fat-feeding. To present a new view for the pathologic association between OSAHS and T2DM.Methods To use prospective animal experiment,randomized controlled study and factorial experiment. The 24 New-Zealand white rabbits(4 months old) were randomly and equally devided into 4 groups, which were control group(C), chronic intermittent hypoxia group(H), high-fat-feeding group (F) and hypoxia & high-fat-feeding group (H+F). Every group involved 6 rabbits. Group H and H+F were placed in an environment into which nitrogen and air were periodically infused every 8 minutes for 5h/day. The lowest level of oxygen concentration was at 8%.Group F and H+F were feeded with fat-rich-stoyer. The intervention experiment lasted for 8 weeks. Blood samples for measurements of total cholesterol(CH), low density lipoprotein cholesterol(LDL-CH) and free fatty acids(FFA), fasting blood glucose(FBG) and fasting insulin(FINS) were withdrawn at 0,4W and 8W. Intravenous glucose tolerance tests(IVGTT) were performed at the end of the interventions. Blood samples for measurements of glucose and insulin were withdrawn at 0min, 3min and 10min.Using H0MA-β,FINS/FBG, insulin area under curve of the first 10 minutes (AUC_ins(0-10min) and acute insulin response(AIR) to assessβcell function.SPSS10.0 was used for statistical analysis. Comparisons among groups were analysed by LSD-test. The effects analysis of two factors of CIH and high-fat-feeding on |3 cell function was carried out using factor analysis.Results 1.Multiple comparsons of lipids. FFA level of group H+F at 8W was (0.75±0.35)mmol/L,which was the highest of the three time pointes (P<0.05),vs(0.20±0.14)mmol/L(0W)and (0.27±0.13) mmol/L(4W).2. Multiple comparsons of FBG and FINS. FBG of group H+F reached to the highest level at 8W((7.56±0.61)mmol/L ),vs FBG at 0W((6.40±0.90)mmol/L),and 4W((6.49±0.65)mmol/L)(P<0.05).There were no significant differences of FINS among not only groups but also time points.3. The 2×2 factorial analysis shows no significant difference inβcell function impairment by CIH. The main effect of high-fat-feeding had statistic significance's the P value of HOMA-β,FINS/FBG,AUC_ins(0-10min) and AIR were 0.001,0.02, 0.03 and 0.04.The two factores had no significant synergistic effects onβcell function impairment.Conclusion 1. The study confirms the negative effects of high-fat-feeding onβcell function and insulin secretion of the first phase.2. The study investigates the associative action of CIH and high-fat-feeding onβcell function of New-Zealand rabbites.Analysis with HOMA-β,FINS/FBG,AUC₍ins(0-10min) and AIR doesn't show significant impairments ofβcell function and the first phase of insulin secretion.