Acid retention in chronic kidney disease is inversely related to GFR.
Greater H+ retention in animal models of chronic kidney disease (CKD) mediates faster glomerular filtration rate (GFR) decline and dietary H+ reduction slows eGFR decline in CKD patients with reduced eGFR and H+ retention due to the high acid (H+) diets of developed societies. We examined if H+ retention in CKD is inversely associated with estimated GFR (eGFR) using cross-sectional and longitudinal analysis of individuals with CKD stage 1 (>90 ml·min- 1·1.73 m-2), CKD stage 2 (60-89 ml/min per 1.73 m2), and CKD stage 3 (30-59 ml·min- 1·1.73 m-2) eGFR. H+ retention was assessed using the difference between observed and expected plasma total CO2 2 h after 0.5 meq/kg body wt oral NaHCO3. H+ retention was higher in CKD 2 vs. CKD 1 ( P < 0.01) and in CKD 3 vs. CKD 2 ( P < 0.02) at baseline and 5 yr, and was higher in CKD 2 vs. CKD 1 ( P < 0.01) at 10 yr. All groups had lower eGFR at subsequent time points ( P < 0.01) but H+ retention was not different among the three time points for CKD 1. By contrast, eGFR decrease was associated with higher H+ retention in CKD 2 at 5 yr ( P = 0.04) and 10 yr ( P < 0.01) and with higher H+ retention in CKD 3 at 5 yr ( P < 0.01). Yearly eGFR decline rate was faster in CKD 2 vs. CKD 1 ( P < 0.01) and in CKD 3 vs. CKD 2 ( P < 0.01). The data show that H+ retention is inversely associated with eGFR, with faster eGFR decline, and support the need for greater dietary H+ reduction therapy for CKD individuals with lower eGFR.
['Goraya|Nimrit|N|', 'Simoni|Jan|J|', 'Sager|Lauren N|LN|', 'Pruszynski|Jessica|J|', 'Wesson|Donald E|DE|']
D000136:Acid-Base Equilibrium D000138:Acidosis D000143:Acids D000284:Administration, Oral D000328:Adult D003430:Cross-Sectional Studies D018450:Disease Progression D005260:Female D005919:Glomerular Filtration Rate D006801:Humans D006863:Hydrogen-Ion Concentration D007668:Kidney D008137:Longitudinal Studies D008297:Male D008875:Middle Aged D011379:Prognosis D051436:Renal Insufficiency, Chronic D012720:Severity of Illness Index D017693:Sodium Bicarbonate D013997:Time Factors
chronic kidney disease GFR diet acidosis bicarbonate