Endocrine
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Congenital leptin deficiency, a rare genetic disorder due to a homozygous mutation in the leptin gene (LEP), is accompanied by extreme obesity and hyperphagia. A number of gastrointestinal hormones have been shown to critically regulate food intake but their physiological role in hyperphagic response in congenital leptin deficiency has not been elucidated. This study is the first to evaluate the fasting and postprandial profiles of gut-derived hormones in homozygous and heterozygous carriers of LEP mutation. ⋯ Interestingly, fasting leptin levels in heterozygotes were not significantly different from controls and did not change significantly following meal. Our results demonstrate that gut hormones play little or no physiological role in driving the hyperphagic response of leptin-deficient subjects. In contrast, fasting and postprandial levels of gut hormones in heterozygous mutation carriers were comparable to those of normal-weight controls.