Pyruvate Dehydrogenase Complex

When the pyruvate dehydrogenase complex is impaired, pyruvate is diverted to lactate via anaerobic glycolysis, yielding only 2 ATP per glucose molecule versus the normal 32–36 ATP — a roughly 16-fold reduction in energy output. Supplying thiamine plus lipoic acid plus a full B-complex is sufficient to restore PDC activity when substrate deficiency is the cause. Patients with chronically elevated pyruvate and lactate are effectively running their metabolism in an anaerobic emergency state even at rest, explaining profound fatigue. Impaired PDC leads to elevated pyruvate, which flows into cholesterol and triglyceride synthesis, establishing a metabolic trajectory toward cardiovascular disease.