不同胰岛素抵抗状态肥胖女性体脂肪分布特点及胰岛β细胞功能变化

Characteristics of body fat distribution and changes of isletβ-cell function among obese women with different insulin resistance status

目的探讨不同胰岛素抵抗状态的非糖尿病肥胖女性体脂肪分布特点及胰岛β细胞功能变化。方法 94例总体脂肪含量≥35%的肥胖女性,采用双能X线骨密度仪检测体成分,计算总体及躯干、上肢、下肢等部位脂肪含量、各部位-总体脂肪比。利用静脉葡萄糖耐量试验计算胰岛素曲线下面积(AUC_(ins))、胰岛素急性分泌时相(AIR)和稳态模型β细胞功能指数(HOMA2-%β)、胰岛素敏感指数(HOMA2-%S)、胰岛素抵抗指数(HOMA2-IR)。按HOMA2-IR值四分位间距分组,比较各组基本临床特征、胰岛β细胞功能、体脂肪含量及分布情况,分析与HOMA2-IR相关的因素;比较不同年龄段上述部分指标的差异。结果随着HOMA2-IR增加,躯干脂肪含量、躯干-总体脂肪比、HOMA2-%β、AUC_(ins)、AIR及葡萄糖耐量试验2h血糖(2hPG)均呈增加趋势,下肢-总体脂肪比和HOMA2-%S则呈减少趋势。HOMA2-IR与躯干脂肪含量、躯干-总体脂肪比及2hPG呈正相关(r=0.358、0.205、0.225,均P<0.05),与年龄、下肢-总体脂肪比呈负相关(r=-0.216、-0.313,均P<0.05)。与年龄>30岁女性比较,≤30岁肥胖女性总体、躯干及四肢脂肪含量较高(均P<0.05),有较高的HOMA2-%β、HOMA2-IR、AIR、AUC_(ins)水平和较低的HOMA2-%S(均P<0.05)。结论非糖尿病的肥胖女性,在高胰岛素抵抗状态下,更趋向于躯干脂肪的堆积及下肢脂肪分布的减少,并伴有胰岛β细胞功能的代偿。

AIM To explore the characteristics of body fat distribution and the changes of islet β-cell function among non-diabetic obese women with different insulin resistance （IR） status. METHODS Dualenergy X-ray absorptiometry （DEXA） was applied to measure the body fat content of 94 obese women whose total body fat content was greater than 35% without exception. Total body, trunk, arm and leg fat content, fat mass in different parts-total fat mass ratio were calculated. Area under the curve of insulin （AUCi.s） , acute insulin response （AIR）, homeostasis model assessment of β-cell function index （HOMA2-%β）, homeostasis model assessment of insulin sensitivity index （HOMA2-% S） and homeostasis model assessment of insulin resistance index （HOMA2-IR） were calculated by using intravenous glucose tolerance test （IVGTF） . The patients were assigned into four groups based on the quartile of HOMA2-IR to compare basic clinical characteristics, islet β-cell function, body fat content and distribution of each group, and investigate the related factors of HOMA2-IR. The differences of the above mentioned indices in different age were identified. RESULTS With the elevation of HOMA2-IR, the trunk fat content, trunk fat-total fat ratio, HOMA2-% β, AUCins, AIR and 2 hours glucose of glucose tolerance test （2hPG） were increased. In contrast, leg fat-total ratio fat and HOMA2-%S were decreased. HOMA2-IR was positively correlated with trunk fat content, trunk fat-total ratio body fat and 2hPG （r = 0.358, 0.205, 0.225, all P 〈 0.05）. However, it showed a negative association with age and leg fat-total fat ratio （r = -0.216, -0.313, all P 〈 0.05）. The obese women who were younger than 30 years old maintained higher total body, trunk fat content and limb fat content （all P 〈 0.05）, as well as higher HOMA2-%β, HOMA2-IR, AIR, AUCins relatively and lower HOMA2-%S （all P 〈 0.05） when compared with the subjects older than 30 years old. CONCLUSION Among non-diabetic obese women with high insulin resistance status, the accumulation of trunk fat and reduction of leg fat distribution are more likely to occur, and the compensatory of islet β-cell function can also be identified.