Analysis of influencing factors of pancreatic fat deposition and the association with islet function in type 2 diabetes mellitus
Objective To analyze the influencing factors of pancreatic fat deposition in patients with type 2 diabetes mellitus(T2DM),and to explore the relationship between pancreatic fat deposition and islet function.Methods A survey on diabetes prevalence was conducted among 548 residents in the Nicheng community of Pudong New Area from October 2015 to December 2016,including 301 patients with T2DM and 247 subjects with normal glucose tolerance(NGT).General information of the subjects were recorded,blood biochemical and insulin indexes were measured,body composition was measured by dual-energy X-ray absorptiometry,and insulin resistance index(HOMA-IR)and islet cell sensitivity index(HOMA-β)were calculated.Fatty liver and pancreatic fat deposition were detected by ultrasound.Both the T2DM group and NGT group were further divided into two subgroups according to the pancreatic fat deposition.Differences in general demographic information,biochemical and body fat indices among the groups were compared.Multivariate logistic regression was used to analyze the influencing factors of pancreatic fat deposition.Results In the NGT group,the subgroup with pancreatic fat deposition showed higher levels of age,waist circumference,waist-to-hip ratio(WHR),body mass index(BMI),fasting insulin levels(FINS),2-hour postprandial insulin levels(2 h INS),triglycerides(TG),uric acid(UA),alanine aminotransferase(ALT),fatty liver prevalence,abdominal fat percentage,and abdomen-to-hip ratio(AHR),compared with the subgroup without pancreatic fat deposition.High-density lipoprotein cholesterol(HDL-C)and limb fat percentage were lower in the subgroup with pancreatic fat deposition.In the T2DM group,the subgroup with pancreatic fat deposition showed higher levels of waist circumference,BMI,FINS,2 h INS,TG,UA,ALT,aspartate aminotransferase(AST),fatty liver prevalence,and abdominal fat percentage,compared with the subgroup without pancreatic fat deposition,with statistically significant differences(P<0.05).The HOMA-IR and HOMA-β in both NGT and T2DM groups with pancreatic fat deposition were significantly higher than those in the groups without pancreatic fat deposition.The prevalence of insulin resistance also significantly increased,with statistically significant differences(P<0.05).The results of multivariate logistic regression analysis showed that HDL-C,HOMA-β,abdominal fat percentage,age and fatty liver were the influencing factors for pancreatic fat deposition in NGT.Conclusion Elderly individuals with abdominal obesity and fatty liver are more prone to developing pancreatic fat deposition,which can affect islet function and aggravate the insulin resistance.