Miyazaki Yoshinori, DeFronzo Ralph A
Department of Medicine, Diabetes Division, University of Texas Health Science Center, San Antonio, TX, USA.
Cardiovasc Diabetol. 2009 Aug 5;8:44. doi: 10.1186/1475-2840-8-44.
All previous studies that investigated the association between abdominal fat distribution and insulin resistance evaluated subcutaneous and visceral fat area and/or volume, but these values were not related to the body type of each subject. In the present study we have examined the association between abdominal fat distribution and peripheral (muscle)/hepatic sensitivity to insulin using the visceral to abdominal subcutaneous fat area ratio (VF/SF ratio) in male patients with type 2 diabetes mellitus. This ratio defines the predominancy of visceral or subcutaneous abdominal adiposity, independent of the body type of each individual.
Thirty-six type 2 diabetic male patients underwent a euglycemic insulin clamp (insulin infusion rate = 40 mU/m2 x min) with 3-3H-glucose to measure insulin-mediated total body (primarily reflects muscle) glucose disposal (TGD) and suppression of endogenous (primarily reflects liver) glucose production (EGP) in response to a physiologic increase in plasma insulin concentration. Abdominal subcutaneous (SF) and intraabdominal visceral fat (VF) areas were quantitated with magnetic resonance imaging (MRI) at the level of L4-5.
TGD and TGD divided by steady state plasma insulin concentration during the insulin clamp (TGD/SSPI) correlated inversely with body mass index (BMI), total fat mass (FM) measured by 3H2O, SF and VF areas, while VF/SF ratio displayed no significant relationship with TGD or TGD/SSPI. In contrast, EGP and the product of EGP and SSPI during the insulin clamp (an index hepatic insulin resistance) correlated positively with VF/SF ratio, but not with BMI, FM, VF or SF.
We conclude that, independent of the individual's body type, visceral fat dominant accumulation as opposed to subcutaneous fat accumulation is associated with hepatic insulin resistance, whereas peripheral (muscle) insulin resistance is more closely related to general obesity (i.e. higher BMI and total FM, and increased abdominal SF and VF) in male patients with type 2 diabetes.
以往所有研究腹部脂肪分布与胰岛素抵抗之间关联的研究，均评估了皮下和内脏脂肪面积及/或体积，但这些数值与每个受试者的体型无关。在本研究中，我们使用内脏与腹部皮下脂肪面积比（VF/SF比），在2型糖尿病男性患者中研究了腹部脂肪分布与外周（肌肉）/肝脏对胰岛素敏感性之间的关联。该比值定义了内脏或皮下腹部肥胖的优势程度，与每个个体的体型无关。
36名2型糖尿病男性患者接受了用3-3H-葡萄糖进行的正常血糖胰岛素钳夹试验（胰岛素输注速率 = 40 mU/m2×min），以测量胰岛素介导的全身（主要反映肌肉）葡萄糖处置（TGD）以及内源性（主要反映肝脏）葡萄糖生成（EGP）对血浆胰岛素浓度生理性升高的抑制情况。在L4-5水平用磁共振成像（MRI）对腹部皮下（SF）和腹内内脏脂肪（VF）面积进行定量。
TGD以及胰岛素钳夹试验期间的TGD除以稳态血浆胰岛素浓度（TGD/SSPI），与体重指数（BMI）、用3H2O测量的总脂肪量（FM）、SF和VF面积呈负相关，而VF/SF比与TGD或TGD/SSPI无显著关系。相比之下，胰岛素钳夹试验期间的EGP以及EGP与SSPI的乘积（肝脏胰岛素抵抗指数）与VF/SF比呈正相关，但与BMI、FM、VF或SF无关。
我们得出结论，在2型糖尿病男性患者中，与皮下脂肪堆积相反，不考虑个体体型，内脏脂肪占优势的堆积与肝脏胰岛素抵抗相关，而外周（肌肉）胰岛素抵抗与总体肥胖（即较高的BMI和总FM，以及腹部SF和VF增加）关系更为密切。
