What substance can be indicative of hypoxia due to anaerobic metabolism?

Lactate is a byproduct of anaerobic metabolism, which occurs when oxygen levels are insufficient for the mitochondria to produce energy through aerobic means. In conditions of hypoxia, the body's cells switch to anaerobic metabolism to generate energy, leading to an increase in lactate production. This accumulation of lactate in the bloodstream is reflected as lactic acidosis, a condition that can indicate the severity of hypoxia and the body's inability to deliver oxygen effectively to tissues. Elevated lactate levels are used clinically to assess tissue perfusion and detect severe metabolic disturbances in critically ill patients.

Other substances listed do not directly indicate hypoxia in the same manner. Glucose is a primary energy source but does not indicate oxygen delivery or consumption directly. Creatinine is primarily a marker of kidney function, and while ammonia can indicate liver dysfunction or metabolic disturbances, it is not directly associated with hypoxia or anaerobic metabolism in the same way as lactate.