Proto Caterina, Romualdi Daniela, Cento Rosa Maria, Romano Corrado, Campagna Giuseppe, Lanzone Antonio
Laboratories Department, Oasi Institute for Research Maria SS, 94018 Troina (EN), Italy.
Metabolism. 2007 Aug;56(8):1076-80. doi: 10.1016/j.metabol.2007.03.016.
Alterations in energy balance and feeding behavior and the subsequent high frequency of obesity are hallmarks of 2 chromosomal diseases: the Prader-Willi syndrome (PWS) and the Down syndrome (DS). Leptin, an important regulator of food intake and energy homeostasis, circulates in 2 forms: a free, therefore active, fraction and a fraction bound to the soluble leptin receptor, whose bioavailability consequently participates in the regulation of leptin action. To investigate the possible role of the free-bound leptin balance in the pathogenesis of obesity in PWS and DS, we enrolled 7 obese women with DS, 5 obese women with PWS, 7 obese women, and 7 normal-weight healthy control women. Basal hormonal concentrations, total and free leptin levels, and leptin receptors levels were measured in plasma samples obtained from the 4 groups. No significant differences were observed in the hormonal milieu. Women with DS exhibited lower total leptin concentrations (P<.01), comparable leptin receptor level and, therefore, lower free leptin values (P<.01) when compared with obese controls, then resembling the profile peculiar to normal-weight control women. At variance, subjects with PWS did not differ from obese controls regarding both leptin and leptin receptor levels. Our data suggest that, whereas subjects with PWS have a leptin assessment corresponding to their degree of obesity, subjects with DS may have a defect in the secretion of leptin that could at least partially account for this form of syndromal obesity.
普拉德-威利综合征（PWS）和唐氏综合征（DS）。瘦素是食物摄入和能量稳态的重要调节因子，以两种形式循环：一种是游离的、因此具有活性的部分，另一种是与可溶性瘦素受体结合的部分，其生物利用度因此参与瘦素作用的调节。为了研究游离-结合瘦素平衡在PWS和DS肥胖发病机制中的可能作用，我们招募了7名肥胖的DS女性、5名肥胖的PWS女性、7名肥胖女性和7名体重正常的健康对照女性。在从这4组中获得的血浆样本中测量基础激素浓度、总瘦素和游离瘦素水平以及瘦素受体水平。在激素环境中未观察到显著差异。与肥胖对照组相比，DS女性的总瘦素浓度较低（P<0.01），瘦素受体水平相当，因此游离瘦素值较低（P<0.01），这与体重正常的对照女性特有的特征相似。与此不同的是，PWS患者在瘦素和瘦素受体水平方面与肥胖对照组没有差异。我们的数据表明，虽然PWS患者的瘦素评估与其肥胖程度相对应，但DS患者可能存在瘦素分泌缺陷，这至少可以部分解释这种综合征性肥胖。
