Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR), National University Health System, Singapore, Singapore.
Agency for Science, Technology and Research (A*STAR), Singapore Institute for Clinical Sciences (SICS), Singapore, Singapore.
Eur J Clin Invest. 2019 May;49(5):e13079. doi: 10.1111/eci.13079. Epub 2019 Feb 25.
The importance of ectopic fat deposition and physical fitness in the pathogenesis of insulin resistance and beta cell dysfunction in subjects from the nonobese Asians is not known.
We conducted a cross-sectional study and measured insulin sensitivity (M value; 4-hour hyperinsulinaemic-euglycaemic clamp), insulin secretion rate (3-hour mixed meal tolerance test with oral minimal modelling), percent body fat, visceral adipose tissue, intramyocellular and intrahepatic lipid contents (magnetic resonance imaging and spectroscopy), cardiorespiratory fitness (VO max; graded exercise test) and habitual physical activity (short International Physical Activity Questionnaire) in 60 healthy nonobese Asian subjects (BMI = 21.9 ± 1.7 kg/m , age = 41.8 ± 13.4 years).
M was inversely associated with percent body fat (r = -0.460, P < 0.001), visceral fat (r = -0.623, P < 0.001) and liver fat (r = -0.601, P < 0.001), whereas insulin secretion correlated positively with these adiposity indices (percent body fat: r = 0.303, P = 0.018; visceral fat: r = 0.409, P = 0.010; hepatic fat: r = 0.393, P = 0.002). VO max correlated negatively with insulin secretion rate (r = -0.420, P < 0.001) and positively with M (r = 0.658, P < 0.001). The amount of vigorous physical activity was positively associated with VO max (r = 0.682, P < 0.001). Multiple stepwise linear regression analyses indicated that VO max, age, and IHTG or VAT were independent determinants of insulin sensitivity and secretion (adjusted R = 69% and 33%, respectively, P < 0.001).
Increased ectopic fat deposition is associated with reduced insulin sensitivity and increased insulin secretion in healthy nonobese Asians. Poor cardiorespiratory fitness, likely due to inadequate participation in vigorous exercise, is strongly related to suboptimal metabolic function. Interventions to encourage engagement in physical activity may thus be important for improving metabolic health in nonobese Asians.
非肥胖亚洲人群中异位脂肪沉积和身体适应性在胰岛素抵抗和β细胞功能障碍发病机制中的重要性尚不清楚。
我们进行了一项横断面研究，测量了胰岛素敏感性（M 值；4 小时高胰岛素-正常血糖钳夹）、胰岛素分泌率（口服最小模型混合餐耐量试验）、体脂百分比、内脏脂肪组织、肌内和肝内脂质含量（磁共振成像和光谱）、心肺适应性（最大摄氧量；递增运动试验）和习惯性体力活动（简短国际体力活动问卷）在 60 名健康非肥胖亚洲受试者（BMI=21.9±1.7kg/m2，年龄=41.8±13.4 岁）中。
M 与体脂百分比（r=-0.460，P<0.001）、内脏脂肪（r=-0.623，P<0.001）和肝脂肪（r=-0.601，P<0.001）呈负相关，而胰岛素分泌与这些肥胖指数呈正相关（体脂百分比：r=0.303，P=0.018；内脏脂肪：r=0.409，P=0.010；肝脂肪：r=0.393，P=0.002）。最大摄氧量与胰岛素分泌率呈负相关（r=-0.420，P<0.001），与 M 呈正相关（r=0.658，P<0.001）。剧烈体力活动量与最大摄氧量呈正相关（r=0.682，P<0.001）。多元逐步线性回归分析表明，最大摄氧量、年龄、IHTG 或 VAT 是胰岛素敏感性和分泌的独立决定因素（调整后的 R2 分别为 69%和 33%，P<0.001）。
非肥胖亚洲人群中异位脂肪沉积增加与胰岛素敏感性降低和胰岛素分泌增加有关。心肺适应性差，可能是由于缺乏剧烈运动，与代谢功能不佳密切相关。因此，鼓励参与体力活动的干预措施可能对改善非肥胖亚洲人的代谢健康很重要。
