Bergia Robert E, Kim Jung Eun, Campbell Wayne W
Department of Nutrition Science, Purdue University, West Lafayette IN 47907, USA.
Food Science and Technology Programme, c/o Department of Chemistry, National University of Singapore, Singapore, Singapore 119077.
Int J Endocrinol. 2018 Sep 4;2018:2751250. doi: 10.1155/2018/2751250. eCollection 2018.
Globally, accumulation of intermuscular adipose tissue (IMAT) is positively associated with insulin resistance. Whether this association is observed consistently in different skeletal muscles and encompasses other markers of cardiometabolic health is not well known.
The purpose of this secondary analysis study was to investigate associations among thigh or calf IMAT stores and indices of cardiometabolic health in adults who are overweight and obese participating in dietary interventions. A subset of calf data was analyzed to assess relations between IMAT in the gastrocnemius (type II fiber predominance) and soleus (type I fiber predominance) with markers of cardiometabolic health.
Thigh and calf compositions were assessed via magnetic resonance imaging in 113 subjects (mean ± SD, age: 50 ± 16 y (range: 21-77 y), BMI: 31 ± 3 kg/m), 103 of which completed dietary interventions with or without energy restriction-induced weight loss. A subset of data ( = 37) was analyzed for relations between muscle compartments (gastrocnemius and soleus) and cardiometabolic health. IMAT was regressed separately against fasting serum glucose concentrations, insulin, homeostatic model assessment-insulin resistance (HOMA-IR), and lipids and lipoproteins.
In general, total thigh IMAT was predictive of markers of glucose control, while total calf IMAT was not. Specifically, baseline thigh IMAT was positively associated with fasting glucose, insulin, and HOMA-IR. IMAT content changes in any depot did not predict improvement in cardiometabolic health.
The strength of the relationship between IMAT and glucose control-related indices of cardiometabolic health is dependent on IMAT location. Specifically, greater IMAT in the thigh is a better predictor of cardiometabolic risk than greater IMAT in the calf in adults who are overweight and obese.
在全球范围内，肌间脂肪组织（IMAT）的蓄积与胰岛素抵抗呈正相关。这种关联在不同的骨骼肌中是否一致存在，以及是否涵盖心脏代谢健康的其他标志物，目前尚不清楚。
这项二次分析研究的目的是调查参与饮食干预的超重和肥胖成年人中，大腿或小腿IMAT储存量与心脏代谢健康指标之间的关联。对一部分小腿数据进行分析，以评估腓肠肌（以II型纤维为主）和比目鱼肌（以I型纤维为主）中的IMAT与心脏代谢健康标志物之间的关系。
通过磁共振成像对113名受试者（平均±标准差，年龄：50±16岁（范围：21 - 77岁），BMI：31±3kg/m²）的大腿和小腿成分进行评估，其中103名受试者完成了有或没有能量限制导致体重减轻的饮食干预。对一部分数据（n = 37）进行分析，以研究肌肉区域（腓肠肌和比目鱼肌）与心脏代谢健康之间的关系。将IMAT分别与空腹血清葡萄糖浓度、胰岛素、稳态模型评估胰岛素抵抗（HOMA-IR）以及脂质和脂蛋白进行回归分析。
总体而言，大腿总IMAT可预测血糖控制指标，而小腿总IMAT则不能。具体而言，基线大腿IMAT与空腹血糖、胰岛素和HOMA-IR呈正相关。任何部位的IMAT含量变化均不能预测心脏代谢健康的改善情况。
IMAT与心脏代谢健康的血糖控制相关指标之间关系的强度取决于IMAT的位置。具体而言，在超重和肥胖成年人中，大腿中较多的IMAT比小腿中较多的IMAT更能预测心脏代谢风险。
