Leonhardt W, Horn R, Brabant G, Breidert M, Temelkova-Kurktschiev T, Fücker K, Hanefeld M
Institute and Policlinic of Clinical Metabolic Research, Technical University Dresden, Germany.
Exp Clin Endocrinol Diabetes. 1999;107(1):46-52. doi: 10.1055/s-0029-1212072.
Impaired glucose tolerance (IGT) is frequently associated with an increased fat mass and an altered fat distribution. The adipocyte derived hormone, leptin has been shown to interact with insulin at various levels and may be intimately involved in this process. However, only limited data concerning the interaction of insulin, glucose tolerance and leptin are available and no data exist on the potential influence of bound vs. free circulating leptin. We therefore studied free and bound leptin in 136 patients (77 males, 59 females) with IGT, in relation to plasma glucose, insulin, proinsulin and C-peptide levels as well as serum free and bound leptin concentrations during an oral glucose tolerance test (oGTT). The expected positive relation of free serum leptin levels with body mass index (BMI) was found. Free leptin concentrations were higher in women than in men. Analysis in tertiles revealed a significant relation between free leptin (16-58, 60-160, and 169-932 pmol/l) and mean fasting insulin levels (65, 93, and 100 pmol/l). This relationship remained significant in a multiple regression analysis with BMI and gender as covariates. Similar independent relationships to leptin serum levels were observed for HbA1c and plasma C peptide levels and the proinsulin/insulin ratio but not for plasma glucose and proinsulin levels. These data suggest a fine tuning of leptin by small changes in circulating insulin levels observed in impaired glucose tolerance.
糖耐量受损（IGT）常与脂肪量增加及脂肪分布改变有关。脂肪细胞分泌的激素瘦素已被证明在多个层面与胰岛素相互作用，可能密切参与了这一过程。然而，关于胰岛素、糖耐量和瘦素相互作用的可用数据有限，且尚无关于结合型与游离型循环瘦素潜在影响的数据。因此，我们研究了136例IGT患者（77例男性，59例女性）的游离和结合型瘦素，以及口服葡萄糖耐量试验（oGTT）期间的血浆葡萄糖、胰岛素、胰岛素原和C肽水平，以及血清游离和结合型瘦素浓度。发现游离血清瘦素水平与体重指数（BMI）呈预期的正相关。女性的游离瘦素浓度高于男性。三分位数分析显示，游离瘦素（16 - 58、60 - 160和169 - 932 pmol/l）与平均空腹胰岛素水平（65、93和100 pmol/l）之间存在显著关系。在以BMI和性别作为协变量的多元回归分析中，这种关系仍然显著。对于糖化血红蛋白（HbA1c）、血浆C肽水平和胰岛素原/胰岛素比值，观察到与瘦素血清水平有类似的独立关系，但对于血浆葡萄糖和胰岛素原水平则未观察到。这些数据表明，在糖耐量受损时，循环胰岛素水平的微小变化对瘦素进行了精细调节。
