Leptin in pediatrics: A hormone from adipocyte that wheels several functions in children - PubMed (original) (raw)

Leptin in pediatrics: A hormone from adipocyte that wheels several functions in children

Ashraf T Soliman et al. Indian J Endocrinol Metab. 2012 Dec.

Abstract

The protein leptin, a pleiotropic hormone regulates appetite and energy balance of the body and plays important roles in controlling linear growth, pubertal development, cardiovascular function, and immunity. Recent findings in the understanding of the structure, functional roles, and clinical significance of conditions with increased and decreased leptin secretion are summarized. Balance between leptin and other hormones is significantly regulated by nutritional status. This balance influences many organ systems, including the brain, liver, and skeletal muscle, to mediate the essential adaptation process. The aim of this review is to summarize the possible physiological functions of leptin and its signaling pathways during childhood and adolescence including control of food intake, energy regulation, growth and puberty, and immunity. Moreover, its secretion and possible roles in the adaptation process during different disease states (obesity, malnutrition, eating disorders, delayed puberty, congenital heart diseases and hepatic disorders) are discussed. The clinical manifestations and the successful management of patients with genetic leptin deficiency and the application of leptin therapy in other diseases including lipodystrophy, states with severe insulin resistance, and diabetes mellitus are discussed.

Keywords: Energy metabolism; growth; immunity; leptin; malnutrition; obesity; overfeeding.

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Conflict of interest statement

Conflict of Interest: None declared

Figures

Figure 1

Figure 1

Leptin effects during obesity Central leptin insufficiency in obesity for extended periods of time results in increased fat accrual, decreased energy expenditure, hyperinsulinemia, hyperglycemia. Hyperleptinemia may increase bone growth and accelerate maturation

Figure 2

Figure 2

Adaptation to prolonged protein energy malnutrition (PEM). During prolonged malnutrition, low leptin levels, decreases leptin inhibition on NPY that affects the regulation of pituitary growth and pituitary adrenal axes and insulin/glucose homeostasis. Stimulation of the hypothalamicpituitary- adrenal (HPA) axis and possibly the hypothalamic-pituitary-GH axis occurs to maintain the high cortisol and GH levels necessary for effective gluconeogenesis and lipolysis to ensure a fuel (glucose and fatty acids) supply for the metabolism of brain and peripheral tissue during nutritional deprivation. The decreased synthesis of IGF-I and the low level of insulin and/or its diminished effect due to an insulin-resistant status in the presence of high circulating GH and cortisol levels ensure substrate diversion away from growth toward metabolic homeostasis

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