Insulin-like signaling is critical for nutrient homeostasis, growth and survival. However, work with lower metazoans-Caenorhabditis elegans and Drosophila-shows that reduced insulin-like signaling extends life span. In addition, reduced insulin signaling in higher animals-rodents and humans-causes glucose intolerance and hyperinsulinemia that progresses to diabetes and shortens the life span of affected individuals. Hyperinsulinemia usually develops to maintain glucose homeostasis and prevent the progression toward life-threatening type 2 diabetes; however, increased circulating insulin may have negative effects on the brain that promote age-related disease. We discuss the possibility that the brain is the site where reduced insulin-like signaling can consistently extend mammalian life span-just as reduced insulin-like signaling extends the life span of lower metazoans.

中文翻译：

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胰岛素样信号传导，营养稳态和寿命。

胰岛素样信号对于营养稳态，生长和存活至关重要。然而，与较低的后生动物-秀丽隐杆线虫和果蝇一起工作表明，减少类胰岛素信号可延长寿命。此外，在高等动物（啮齿动物和人类）中减少的胰岛素信号传导会导致葡萄糖耐受不良和高胰岛素血症，这种疾病会发展为糖尿病，并缩短受影响个体的寿命。高胰岛素血症通常发展为维持葡萄糖稳态，并防止发展为威胁生命的2型糖尿病。但是，循环胰岛素的增加可能会对大脑产生不利影响，从而促进与年龄有关的疾病。