What to watch with APOE and fatigue?

The link between APOE variants (especially ε4) and fatigue is not clearly established. APOE ε4 is a risk factor for Alzheimer's and cardiovascular disease, which can indirectly contribute to fatigue. However, fatigue is multifactorial (sleep, diet, stress, exercise). A genetic test alone does not provide clinical guidance. Have your blood markers (iron, vitamin D, thyroid) checked by a doctor and focus on lifestyle factors. Evidence: unclear, as no direct gene-fatigue association is mentioned in the provided sources.