Causal Effect of Coenzyme Q10 Nutrition and Cognitive Dysfunction in the Metabolic Storm (Hyperglycemia and Sarcopenia) and Brain-derived Neurotrophic Factor

This study is exploring whether taking Coenzyme Q10 supplements (a natural antioxidant) can improve brain function in older adults with mild cognitive impairment or Alzheimer's disease who also have high blood sugar or muscle weakness. **You may be eligible if...** - You have been diagnosed with mild cognitive impairment (MCI) or Alzheimer's disease - You also have elevated fasting blood sugar (100 mg/dL or higher) or signs of muscle weakness/low muscle mass - You are able to swallow tablets **You may NOT be eligible if...** - You have cancer - You have severe heart, lung, liver, or kidney disease - You are significantly malnourished or have had major weight loss recently - You are already taking Coenzyme Q10 supplements - You take the blood thinner warfarin - You have severe disability or are unable to communicate (aphasia) Talk to your doctor to see if this trial is right for you.