What role does Insulin play in Müdigkeit?

Insulin is a key hormone in energy metabolism, facilitating glucose uptake into cells and regulating blood sugar levels. Dysregulation—such as insulin resistance or reactive hypoglycemia—can contribute to fatigue. In insulin resistance, cells become less responsive, leading to reduced glucose entry and a cellular energy deficit, which manifests as tiredness. Reactive hypoglycemia, a sharp drop in blood sugar after a high-carb meal, can also cause fatigue. However, fatigue is multifactorial; sleep quality, stress, thyroid function, and nutritional status are equally important. The evidence for a direct causal role of insulin in fatigue is moderate—strong mechanistic understanding exists, but most human studies are observational or associative. Consumer DNA tests like MyBody-X may analyze SNPs in insulin-related genes (e.g., IRS1, PPARG), but these cannot diagnose insulin resistance or fatigue. For persistent fatigue, clinical evaluation including fasting glucose, insulin, and HbA1c is recommended.