Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Ann Intern Med. 2010 Jan 19;152(2):93-100. doi: 10.7326/0003-4819-152-2-201001190-00008.
Leptin is a hormone secreted by adipose tissue in direct proportion to amount of body fat. The circulating leptin levels serve as a gauge of energy stores, thereby directing the regulation of energy homeostasis, neuroendocrine function, and metabolism. Persons with congenital deficiency are obese, and treatment with leptin results in dramatic weight loss through decreased food intake and possible increased energy expenditure. However, most obese persons are resistant to the weight-reducing effects of leptin. Recent studies suggest that leptin is physiologically more important as an indicator of energy deficiency, rather than energy excess, and may mediate adaptation by driving increased food intake and directing neuroendocrine function to converse energy, such as inducing hypothalamic hypogonadism to prevent fertilization. Current studies investigate the role of leptin in weight-loss management because persons who have recently lost weight have relative leptin deficiency that may drive them to regain weight. Leptin deficiency is also evident in patients with diet- or exercise-induced hypothalamic amenorrhea and lipoatrophy. Replacement of leptin in physiologic doses restores ovulatory menstruation in women with hypothalamic amenorrhea and improves metabolic dysfunction in patients with lipoatrophy, including lipoatrophy associated with HIV or highly active antiretroviral therapy. The applications of leptin continue to grow and will hopefully soon be used therapeutically.
瘦素是脂肪组织按体脂量成比例分泌的一种激素。循环中的瘦素水平可作为能量储存的指标，从而指导能量稳态、神经内分泌功能和代谢的调节。先天性瘦素缺乏的人会肥胖，而瘦素治疗可通过减少食物摄入和可能增加能量消耗导致体重明显减轻。然而，大多数肥胖者对瘦素的减肥效果有抗性。最近的研究表明，瘦素作为能量缺乏的指标，其生理意义更为重要，而不是能量过剩，并且可能通过驱动增加食物摄入和引导神经内分泌功能来适应能量，例如诱导下丘脑性腺功能减退症以防止受精，从而发挥作用。目前的研究探讨了瘦素在体重管理中的作用，因为最近体重减轻的人可能存在相对的瘦素缺乏，这可能促使他们恢复体重。瘦素缺乏也见于饮食或运动引起的下丘脑闭经和脂肪萎缩症患者中。生理剂量的瘦素替代可恢复下丘脑闭经妇女的排卵性月经，并改善脂肪萎缩症患者的代谢功能障碍，包括与 HIV 或高效抗逆转录病毒治疗相关的脂肪萎缩症。瘦素的应用不断增加，希望很快就能在治疗中得到应用。
