Metabolic acidosis is most commonly seen in which of the following conditions?

Metabolic acidosis is characterized by a decrease in blood pH due to a primary decrease in bicarbonate. Diabetic ketoacidosis (DKA) is a classic cause of metabolic acidosis, in which insufficient insulin leads to fat breakdown and accumulation of ketone bodies (acetoacetate, beta-hydroxybutyrate), which are acidic. Other causes include lactic acidosis, renal failure, and diarrhea. SLE, hypertension, and hypothyroidism are not primary causes of metabolic acidosis.