Sandhofer Anton, Laimer Markus, Ebenbichler Christoph F, Kaser Susanne, Paulweber Bernhard, Patsch Josef R
Department of Medicine, University of Innsbruck, Innsbruck, Austria.
Obes Res. 2003 Jun;11(6):760-8. doi: 10.1038/oby.2003.106.
In obesity, plasma leptin is high and soluble leptin receptor (sOb-R) levels are low, resulting in a low fraction of bound leptin. The aim of this study was to investigate the influence of insulin resistance (IR) and the metabolic syndrome (MS) on sOb-R concentration and the bound-free ratio of leptin.
sOb-R, leptin levels, and homeostasis model assessment (HOMA) index for IR were determined in 76 middle-aged obese or overweight men.
Concentration of sOb-R and soluble receptor-bound fraction of leptin were lowest in the highest tertile of HOMA-IR. sOb-R and the bound-free ratio of leptin correlated with HOMA-IR, leptin concentration, and waist-to-hip ratio independently of age, BMI, and fat mass. Leptin and waist-to-hip ratio were the sole independent determinants of sOb-R concentration, and BMI, HOMA-IR, and visceral adipose tissue were independent determinants of the bound fractin of leptin. sOb-R concentration and the bound fraction of leptin decreased with increasing numbers of components of the MS, resulting in lower sOb-R concentration and a lower fraction of bound leptin in men with the MS.
IR and abdominal obesity are associated with low sOb-R concentration and low bound-free ratio of leptin independent of fat mass. Low sOb-R concentration and low bound-free ratio of leptin segregate with components of the MS. We suggest that low sOb-R levels and a low fraction of specifically bound leptin are markers of leptin resistance, which is independently associated with IR and abdominal obesity and may constitute an additional component of the MS.
在肥胖症中，血浆瘦素水平较高，而可溶性瘦素受体（sOb-R）水平较低，导致结合型瘦素的比例较低。本研究的目的是调查胰岛素抵抗（IR）和代谢综合征（MS）对sOb-R浓度及瘦素结合-游离比例的影响。
对76名中年肥胖或超重男性测定sOb-R、瘦素水平及用于评估IR的稳态模型评估（HOMA）指数。
在HOMA-IR最高三分位数组中，sOb-R浓度及瘦素的可溶性受体结合比例最低。sOb-R及瘦素的结合-游离比例与HOMA-IR、瘦素浓度及腰臀比相关，且独立于年龄、体重指数（BMI）和脂肪量。瘦素及腰臀比是sOb-R浓度的唯一独立决定因素，而BMI、HOMA-IR及内脏脂肪组织是瘦素结合比例的独立决定因素。随着MS组分数量的增加，sOb-R浓度及瘦素的结合比例降低，导致MS男性的sOb-R浓度较低且结合型瘦素比例较低。
IR和腹型肥胖与低sOb-R浓度及低瘦素结合-游离比例相关，且独立于脂肪量。低sOb-R浓度及低瘦素结合-游离比例与MS的组分相关。我们认为，低sOb-R水平及低特异性结合型瘦素比例是瘦素抵抗的标志物，其与IR和腹型肥胖独立相关，可能构成MS的一个额外组分。
