Mayo Clinic, Endocrine Research Unit, 200 First Street SW, Room 5-194 Joseph, Rochester, Minnesota 55905, USA.
J Clin Endocrinol Metab. 2012 Nov;97(11):4130-8. doi: 10.1210/jc.2012-2285. Epub 2012 Aug 29.
A central/visceral fat distribution and excess free fatty acid (FFA) availability are associated with dyslipidemia and insulin resistance. However, these two characteristics often coexist, making it difficult to detect the independent contributions of each. Whether FFA suppression is more closely linked to metabolic abnormalities is not clear.
The aim of the study was to examine the relationship between FFA suppression, body fat distribution, and fitness as contributors toward insulin resistance and hypertriglyceridemia.
We measured systemic palmitate turnover using an iv infusion of [9,10-(3)H]palmitate; upper body sc adipose tissue (UBSQ) and visceral adipose tissue (VAT) with dual-energy x-ray absorptiometry and a single-slice abdominal computed tomography scan; fitness with a graded exercise treadmill test; and insulin sensitivity with both the iv glucose tolerance test (IVGTT) (SI(IVGTT)) and mixed meal tolerance test (SI(Meal)).
The study was conducted at a General Clinical Research Center.
Baseline data were obtained from 140 elderly adults (age, 60-88 yr; 83 males) and 60 young adults (age, 18-31 yr; 31 males) who participated in a previously published trial assessing the effects of 2-yr supplementation of dehydroepiandrosterone or testosterone on body composition, glucose metabolism, and bone density.
There were no interventions.
We measured fasting plasma triglyceride (TG) concentrations, SI(IVGTT), and SI(Meal).
Using multivariate regression analysis, the strongest combined predictors of TG concentrations were VAT, postmeal nadir FFA concentrations, sex, and age. The best predictors of SI(IVGTT) were IVGTT nadir palmitate concentration, VAT, UBSQ fat, fitness, and age, whereas the best predictors of SI(Meal) were meal nadir palmitate concentration, UBSQ fat, fitness, and sex.
FFA suppression is associated with both fasting TG concentrations and insulin sensitivity, independent of measures of adiposity.
中心/内脏脂肪分布和游离脂肪酸（FFA）的过度供应与血脂异常和胰岛素抵抗有关。然而，这两个特征经常同时存在，使得很难检测到每个特征的独立贡献。FFA 抑制是否与代谢异常更密切相关尚不清楚。
本研究旨在研究 FFA 抑制、体脂分布和健康状况与胰岛素抵抗和高甘油三酯血症的关系。
我们通过静脉输注[9,10-(3)H]棕榈酸来测量全身棕榈酸周转率；使用双能 X 射线吸收仪和单切腹部计算机断层扫描来测量上半身皮下脂肪组织（UBSQ）和内脏脂肪组织（VAT）；使用分级运动跑步机测试来测量健康状况；通过静脉葡萄糖耐量试验（IVGTT）（SI(IVGTT)）和混合餐耐量试验（SI(Meal)）来测量胰岛素敏感性。
该研究在一般临床研究中心进行。
基线数据来自之前发表的一项试验，该试验评估了脱氢表雄酮或睾酮 2 年补充对身体成分、葡萄糖代谢和骨密度的影响，共纳入 140 名老年人（年龄 60-88 岁；83 名男性）和 60 名年轻人（年龄 18-31 岁；31 名男性）。
无干预措施。
我们测量了空腹血浆甘油三酯（TG）浓度、SI(IVGTT)和 SI(Meal)。
使用多元回归分析，TG 浓度的最强联合预测因子是 VAT、餐后 FFA 浓度、性别和年龄。SI(IVGTT)的最佳预测因子是 IVGTT 谷值棕榈酸浓度、VAT、UBSQ 脂肪、健康状况和年龄，而 SI(Meal)的最佳预测因子是餐后 FFA 浓度、UBSQ 脂肪、健康状况和性别。
FFA 抑制与空腹 TG 浓度和胰岛素敏感性有关，与肥胖指标无关。
