Systemic effects of metabolic acidosis

Metabolic acidosis is a primary reduction in serum bicarbonate concentration and a consequent decrease in blood pH, which has profound implications for systemic physiology. This literature review synthesizes the current evidence of metabolic acidosis's effect on cardiovascular, vascular, pulmonary, gastrointestinal, endocrine, musculoskeletal, renal, and metabolic systems. Cardiovascular effects include impaired cardiac contractility, altered ion exchange currents, and decreased β-adrenergic response. Vascular response is dependent on vessel size, promoting vasodilation in large arteries and vasoconstriction in small vessels via NO and Ca²⁺-dependent pathways. Pulmonary adaptations include hyperventilation, altered hemoglobin-oxygen affinity via the Bohr effect, and increased pulmonary vascular resistance. Gastrointestinal effects include activation of acid-sensitive neuronal pathways causing increased mucus gel thickness, HCO₃^- secretion, and mucosal blood flow. Endocrine effects include growth hormone resistance, decreased thyroid hormone secretion, and negative shifts in Ca²⁺-PO4- balance. Renal effects include predisposition to calcium-oxalate stones and acceleration of chronic kidney disease through inflammatory mechanisms. Overall, this review aims to explore the physiological effects of metabolic acidosis, highlighting mechanism contributing to organ dysfunction.