title: Correction of metabolic acidosis improves insulin resistance in chronic kidney disease.
abstract: Correction of metabolic acidosis (MA) with nutritional therapy or bicarbonate administration is widely used in chronic kidney disease (CKD) patients. However, it is unknown whether these interventions reduce insulin resistance (IR) in diabetic patients with CKD. We sought to evaluate the effect of MA correction on endogenous insulin action in diabetic type 2 (DM2) CKD patients.
  
  
  
  A total of 145 CKD subjects (83 men e 62 women) with DM2 treated with oral antidiabetic drugs were included in the study and followed up to 1 year. All patients were randomly assigned 1:1 to either open-label (A) oral bicarbonate to achieve serum bicarbonate levels of 24-28 mmol/L (treatment group) or (B) no treatment (control group). The Homeostatic model assessment (HOMA) index was used to evaluate IR at study inception and conclusion. Parametric and non-parametric tests as well as linear regression were used.
  
  
  
  At baseline no differences in demographic and clinical characteristics between the two groups was observed. Average dose of bicarbonate in the treatment group was 0.7 ± 0.2 mmol/kg. Treated patients showed a better metabolic control as confirmed by lower insulin levels (13.4 ± 5.2 vs 19.9 ± 6.3; for treated and control subjects respectively; p < 0.001), Homa-IR (5.9[5.0-7.0] vs 6.3[5.3-8.2]; p = 0.01) and need for oral antidiabetic drugs. The serum bicarbonate and HOMA-IR relationship was non-linear and the largest HOMA-IR reduction was noted for serum bicarbonate levels between 24 and 28 mmol/l. Adjustment for confounders, suggests that serum bicarbonate rather than treatment drives the effect on HOMA-IR.
  
  
  
  Serum bicarbonate is related to IR and the largest HOMA-IR reduction is noted for serum bicarbonate between 24 and 28 mmol/l. Treatment with bicarbonate influences IR. However, changes in serum bicarbonate explains the effect of treatment on HOMA index. Future efforts are required to validate these results in diabetic and non-diabetic CKD patients.
  
  
  
  The trial was registered at www.clinicaltrial.gov (Use of Bicarbonate in Chronic Renal Insufficiency (UBI) study - NCT01640119 ).
authors: Department of Nephrology and Dialysis, ASST-Lariana, Ospedale Sant' Anna, Como, (CO), Italy.
authors: Antonio
authors: A
authors: Bellasi
authors: Department of Nephrology and Dialysis, UOC Nefrologia, PO "A Landolfi", Via Melito, snc, I-83029, Solofra, (AV), Italy.
authors: Lucia
authors: L
authors: Di Micco
authors: Department of Clinical and Experimental Medicine, Unit of Nephrology, University of Messina, Messina, Italy.
authors: Domenico
authors: D
authors: Santoro
authors: Department of Pharmacy, School of Pharmacy, University of Salerno, Fisciano, (SA), Italy.
authors: Stefania
authors: S
authors: Marzocco
authors: Department of Nephrology and Dialysis, UOC Nefrologia, PO "A Landolfi", Via Melito, snc, I-83029, Solofra, (AV), Italy.
authors: Emanuele
authors: E
authors: De Simone
authors: Department of Health Sciences, University of Milan, Milan, Italy.
authors: Mario
authors: M
authors: Cozzolino
authors: Department of Nephrology and Dialysis, Ospedale Parodi, Delfino, Colleferro, (Rome), Italy.
authors: Luca
authors: L
authors: Di Lullo
authors: Dialysis, Sant'Angelo dei Lombardi, Avellino, Italy.
authors: Pasquale
authors: P
authors: Guastaferro
authors: Department of Nephrology and Dialysis, UOC Nefrologia, PO "A Landolfi", Via Melito, snc, I-83029, Solofra, (AV), Italy. br.diiorio@gmail.com.
authors: Biagio
authors: B
authors: Di Iorio
mesh_terms: D000138:Acidosis / Q000097:blood* / Q000188:drug therapy*; D000368:Aged; D001639:Bicarbonates / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000188:drug therapy*; D017693:Sodium Bicarbonate / Q000627:therapeutic use
chemical_list: D001639:Bicarbonates; D007004:Hypoglycemic Agents; D017693:Sodium Bicarbonate
keywords: CKD; Diabetes; Homa-test; Metabolic acidosis; Sodium bicarbonate