颈背部皮肤发黑可能是胰岛素抵抗和糖尿病的早期迹象。

图片中的后颈部皮肤呈深色是黑棘皮病（Acanthosis Nigricans）的表现，黑棘皮病是指皮肤发黑变厚，尤其是颈部两侧或颈背部、腋下、乳房下和腹股沟的皮肤变化最明显。

黑棘皮病是机体高胰岛素水平的一个信号，也可以用来预测糖尿病的风险。及时调节生活方式，平衡荷尔蒙，从而平稳血糖水平，黑棘皮病将消失。

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