Consequences of Metabolic Acidosis in Chronic Kidney Disease Patients

Metabolic acidosis is an inevitable complication associated with progressive loss of kidney function. It appears when glomerular filtration rate (GFR) falls below 25 ml/min/ 1.73 m. Metabolic acidosis arises from the difference between the excretion of hydrogen and the synthesis of ammonia ions. Damaged renal tubules cannot contribute in maintaining the acid base balance by reabsorbing the daily filtrated HCO3 − and synthesizing new HCO3 − ions. Although usually mild to moderate, it may lead to several metabolic complications. Metabolic acidosis is one of the important causes of protein energy wasting (PEW) and can trigger muscle loss in patients dealing with chronic kidney disease (CKD). Furthermore, it contributes to the development of chronic kidney disease-metabolic bone disease by increasing the bone resorption and inhibiting the bone formation. It has been shown that the acidic environment could play an important role in regulation of the hepcidin homeostasis and thus, be one of the factors contributing to the etiology of the anemia of chronic disease. It is also known that metabolic acidosis can severely affect kidney function by causing progressive tubulointerstitial injury and decline in glomerular filtration rate. All these metabolic effects are complex but can be successfully managed. Series of studies provide evidence that bicarbonate therapy is beneficial in these patients. It helps in achieving the balance between calcium and phosphate. Furthermore, it improves dietary protein intake and lean body mass and slows down the decline in glomerular filtration rate. Thus, metabolic acidosis needs to be monitored and carefully corrected.