Toll of Chronic Metabolic Acidosis at Molecular, Cellular, and Systemic Levels: A Conceptual Framework to Revisit...

Background/Objectives: Chronic metabolic acidosis (CMA) is a mild, persistent acid-base imbalance characterized by low serum bicarbonate and urinary pH and is common in chronic illness, aging, and metabolic disorders such as type 2 diabetes (T2D). This review highlights the critical, yet often overlooked, role of CMA in T2D (CMAD) and its contribution to disease pathophysiology. Methods: We conducted a comprehensive review of the systemic impacts of CMA, from molecular mechanisms to organ-specific dysfunction. The analysis covers physiological pH dynamics in intracellular (IC) and extracellular (EC) fluids and explores their effects on cellular processes, including the cell cycle and apoptosis. Results: At the molecular level, acidosis significantly alters enzyme kinetics, macromolecule metabolism, and ion conductance. Cell-level analysis shows that pH shifts impact proliferation and programmed cell death. Systemically, the manifestations of CMA align closely with T2D features in vital organs, including the pancreas, liver, skeletal muscle, adipose tissue, and the renal, nervous, and immune systems. Our findings indicate that the pathophysiological landscape of T2D largely mirrors the biological effects of chronic acidosis. Conclusions: The alignment between the effects of CMA and the clinical features of T2D suggests that T2D pathophysiology is worth revisiting through the lens of CMAD. This perspective is further supported by therapeutic interventions showing preliminary efficacy signals in limited studies of acid-neutralization in managing T2D symptoms and progression.