腹部脂肪分布对2型糖尿病患者人体成分及胰岛功能的影响

Impacts of abdominal fat distribution on body composition and islet function in type 2 diabetic patients

目的分析2型糖尿病(T2DM)伴或不伴非酒精性脂肪性肝病(NAFLD),以及伴或不伴腹型肥胖患者的人体成分及胰岛功能的差异,探讨脂肪肝及内脏脂肪对胰岛功能的影响。方法选取519例T2DM患者,根据有无脂肪肝以及是否合并腹型肥胖分为4组,组1:T2DM+NAFLD伴腹型肥胖组242例,组2:T2DM+NAFLD无腹型肥胖组59例,组3:T2DM无NAFLD伴腹型肥胖组101例,组4:T2DM无NAFLD无腹型肥胖组117例。应用生物电阻抗法进行人体成分分析,包括内脏脂肪面积、骨骼肌含量、矿物质含量等指标,同时测定所有患者的肝肾功能、血脂、口服葡萄糖耐量、胰岛功能等生化指标。运用方差分析或非参数检验比较各组人体成分及生化指标,相关性分析采用Spearman秩相关,多因素分析采用二元logistic回归方法。结果(1)组1矿物质含量、蛋白质含量、身体总水分、体重指数大于组4(F=16.202~100.482,P均<0.05);组1~组4脂肪百分比逐渐下降(T=47.027,P<0.05);组2骨骼肌含量高于组1(T=2.879,P<0.05)。(2)组1~组4白细胞、C反应蛋白、总蛋白、γ-谷氨酰转肽酶、谷丙转氨酶、谷草转氨酶、肾小球滤过率、血尿酸、甘油三酯、低密度脂蛋白-胆固醇、极低密度脂蛋白-胆固醇呈下降趋势,高密度脂蛋白-胆固醇逐渐上升(F/T=4.036~18.831,P均<0.05)。(3)组1~组4胰岛功能指标:稳态模型评估-胰岛素抵抗指数、稳态模型评估-β细胞功能指数、胰岛素敏感性指数、葡萄糖负荷后胰岛素曲线下面积、C肽曲线下面积呈下降趋势,其中组1与组4间差异有统计学意义(F/T=5.757~13.860,P均<0.05)。(4)校正年龄、性别后,内脏脂肪面积与体重指数、腰臀比、内脏脂肪含量、皮下脂肪含量、基础代谢量、γ-谷氨酰转肽酶、谷丙转氨酶、谷草转氨酶、血尿酸呈正相关(r=0.340~0.916,P均<0.05),与高低密度脂蛋白-胆固醇呈负相关(r=-0.442,P<0.05)。(5)内脏脂肪含量(OR=5.463,95%CI:1.886~4.451,P=0.071)、极低密度脂蛋白-胆固醇(OR=1.224,95%CI:1.180~1.227,P=0.025)为T2DM患者NAFLD的独立危险因素。结论T2DM合并NAFLD或腹型肥胖患者均会发生胰岛素抵抗及胰岛β细胞功能代偿性增高,且当T2DM患者同时合并NAFLD及腹型肥胖时胰岛素抵抗的程度最明显。增加骨骼肌的含量有利于控制NAFLD患者的腹型肥胖及改善胰岛功能。减少内脏脂肪面积有利于改善代谢指标。

Objective To analyze the differences of body composition and islet function between patients with or without nonalcoholic fatty liver disease(NAFLD),and between patients with or without visceral obesity in type 2 diabetes mellitus(T2DM).The effects of fatty liver and visceral fat on islet function were also investigated.Methods A total of 519 patients with T2DM were divided into 4 groups according to the presence or absence of fatty liver and visceral obesity.Group 1:242 cases of T2DM+NAFLD with visceral obesity,group 2:59 cases of T2DM+NAFLD without visceral obesity,group 3:101 cases of T2DM with visceral obesity but without NAFLD and group 4:117 cases of T2DM without NAFLD and visceral obesity.Bioelectrical impedance method was used to analyze human body composition,including visceral fat area,skeletal muscle content,mineral content and other indicators.At the same time,biochemical indicators such as liver and kidney function,blood lipid,oral glucose tolerance and islet function were measured in all patients.Variance analysis or nonparametric test was used to compare the difference of body composition and biochemical indexes between groups.Spearman rank correlation was used for correlation analysis,and binary logistic regression was used for multivariate analysis.Results(1)The mineral content,protein content,total body water,body mass index in group 1 were higher than those in group 4(F=16.202-100.482,all P<0.05);the percentage of fat was decreased gradually from group 1 to group 4(T=47.027,P<0.05);the skeletal muscle content in group 2 was higher than that in group 1(T=2.879,P<0.05).(2)The white blood cell,C-reactive protein,total protein,albumin,gamma glutamyl transferase,alanine aminotransferase,aspertate aminotransferase,estimated glomerular filtration rate,serum uric acid,triglyceride,low-density lipoprotein-cholesterol and very low-density lipoprotein-cholesterol showed a downward trend,and the level of high density lipoprotein-cholesterol was increased gradually(F/T=4.036-18.831,all P<0.05)from group 1 to group 4.(3)Among the four groups,homeostatic model assessment of insulin resistance,homeostasis model assessment ofβcell function,insulin sensitivity index,area under curve of insulin and area under curve of C-peptide showed a downward trend from group 1 to group 4,with significant difference between group 1 and group 4(F/T=5.757-13.860,all P<0.05).(4)After adjusting for age and sex,the visceral fat area was positively correlated with body mass index,waist to hip ratio,visceral fat content,subcutaneous fat content,basal metabolic volume,gamma glutamyl transferase,alanine aminotransferase,aspertate aminotransferase and serum uric acid(r=0.340-0.916,all P<0.05),and negatively correlated with high density lipoprotein-cholesterol(r=-0.442,P<0.05).(5)Visceral fat content(OR=5.463,95%CI:1.886-4.451,P=0.071)and low-density lipoprotein-cholesterol(OR=1.224,95%CI:1.180-1.227,P=0.025)were independent risk factors for NAFLD in patients with T2DM.Conclusions Both T2DM patients with NAFLD or visceral obesity have insulin resistance and compensatory increase of insulin secretion.The most serious insulin resistance is found in T2DM patients with NAFLD and visceral obesity simultaneously.Increasing skeletal muscle content is beneficial to control visceral obesity and improve islet function in patients with NAFLD.Reducing visceral fat area is beneficial to improve metabolic indicators.