1
|
Molnar AO, Killin L, Bota S, McArthur E, Dixon SN, Garg AX, Harris C, Thompson S, Tennankore K, Blake PG, Bohm C, MacRae J, Silver SA. Association Between the Dialysate Bicarbonate and the Pre-dialysis Serum Bicarbonate Concentration in Maintenance Hemodialysis: A Retrospective Cohort Study. Can J Kidney Health Dis 2024; 11:20543581241256774. [PMID: 38827142 PMCID: PMC11141227 DOI: 10.1177/20543581241256774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/23/2024] [Indexed: 06/04/2024] Open
Abstract
Background It is unclear whether the use of higher dialysate bicarbonate concentrations is associated with clinically relevant changes in the pre-dialysis serum bicarbonate concentration. Objective The objective is to examine the association between the dialysate bicarbonate prescription and the pre-dialysis serum bicarbonate concentration. Design This is a retrospective cohort study. Setting The study was performed using linked administrative health care databases in Ontario, Canada. Patients Prevalent adults receiving maintenance in-center hemodialysis as of April 1, 2020 (n = 5414) were included. Measurements Patients were grouped into the following dialysate bicarbonate categories at the dialysis center-level: individualized (adjustment based on pre-dialysis serum bicarbonate concentration) or standardized (>90% of patients received the same dialysate bicarbonate concentration). The standardized category was stratified by concentration: 35, 36 to 37, and ≥38 mmol/L. The primary outcome was the mean outpatient pre-dialysis serum bicarbonate concentration at the patient level. Methods We examined the association between dialysate bicarbonate category and pre-dialysis serum bicarbonate using an adjusted linear mixed model. Results All dialysate bicarbonate categories had a mean pre-dialysis serum bicarbonate concentration within the normal range. In the individualized category, 91% achieved a pre-dialysis serum bicarbonate ≥22 mmol/L, compared to 87% in the standardized category. Patients in the standardized category tended to have a serum bicarbonate that was 0.25 (95% confidence interval [CI] = -0.93, 0.43) mmol/L lower than patients in the individualized category. Relative to patients in the 35 mmol/L category, patients in the 36 to 37 and ≥38 mmol/L categories tended to have a serum bicarbonate that was 0.70 (95% CI = -0.30, 1.70) mmol/L and 0.87 (95% CI = 0.14, 1.60) mmol/L higher, respectively. There was no effect modification by age, sex, or history of chronic lung disease. Limitations We could not directly confirm that all laboratory measurements were pre-dialysis. Data on prescribed dialysate bicarbonate concentrations for individual dialysis sessions were not available, which may have led to some misclassification, and adherence to a practice of individualization could not be measured. Residual confounding is possible. Conclusions We found no significant difference in the pre-dialysis serum bicarbonate concentration irrespective of whether an individualized or standardized dialysate bicarbonate was used. Dialysate bicarbonate concentrations ≥38 mmol/L (vs 35 mmol/L) may increase the pre-dialysis serum bicarbonate concentration by 0.9 mmol/L.
Collapse
Affiliation(s)
- Amber O. Molnar
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON, Canada
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
- Population Health Research Institute, McMaster University/Hamilton Health Sciences, ON, Canada
- St. Joseph’s Healthcare Hamilton, Hamilton, ON, Canada
| | - Lauren Killin
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Lawson Health Research Institute, London Health Sciences Centre, ON, Canada
| | - Sarah Bota
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Lawson Health Research Institute, London Health Sciences Centre, ON, Canada
| | - Eric McArthur
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Lawson Health Research Institute, London Health Sciences Centre, ON, Canada
| | - Stephanie N. Dixon
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Lawson Health Research Institute, London Health Sciences Centre, ON, Canada
| | - Amit X. Garg
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
- Lawson Health Research Institute, London Health Sciences Centre, ON, Canada
- Division of Nephrology, Department of Medicine, Western University, London, ON, Canada
- Department of Epidemiology, Western University, London, ON, Canada
| | - Claire Harris
- Division of Nephrology, Department of Medicine, The University of British Columbia, Vancouver, Canada
| | - Stephanie Thompson
- Division of Nephrology, Department of Medicine, University of Alberta, Edmonton, Canada
| | - Karthik Tennankore
- Division of Nephrology, Department of Medicine, Nova Scotia Health Authority, Halifax, Canada
| | - Peter G. Blake
- Division of Nephrology, Department of Medicine, Western University, London, ON, Canada
| | - Clara Bohm
- Division of Nephrology, Department of Medicine, University of Manitoba, Winnipeg, Canada
| | - Jennifer MacRae
- Division of Nephrology, Department of Medicine, University of Calgary, AB, Canada
| | - Samuel A. Silver
- Institute for Clinical Evaluative Sciences, London, ON, Canada
- Division of Nephrology, Department of Medicine, Queen’s University, Kingston, ON, Canada
| |
Collapse
|
2
|
Kraut JA, Madias NE. Adverse Effects of the Metabolic Acidosis of Chronic Kidney Disease. Adv Chronic Kidney Dis 2017; 24:289-297. [PMID: 29031355 DOI: 10.1053/j.ackd.2017.06.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/27/2017] [Indexed: 01/01/2023]
Abstract
The kidney has the principal role in the maintenance of acid-base balance, and therefore, a fall in renal net acid excretion and positive H+ balance often leading to reduced serum [HCO3-] are observed in the course of CKD. This metabolic acidosis can be associated with muscle wasting, development or exacerbation of bone disease, hypoalbuminemia, increased inflammation, progression of CKD, protein malnutrition, alterations in insulin, leptin, and growth hormone, and increased mortality. Importantly, some of the adverse effects can be observed even in the absence of overt hypobicarbonatemia. Administration of base decreases muscle wasting, improves bone disease, restores responsiveness to insulin, slows progression of CKD, and possibly reduces mortality. Base is recommended when serum [HCO3-] is <22 mEq/L, but the target serum [HCO3-] remains unclear. Evidence that increments of serum [HCO3-] >26 mEq/L might be associated with worsening of cardiovascular disease adds complexity to treatment decisions. Further study of the mechanisms through which positive H+ balance in CKD contributes to its various adverse effects and the pathways involved in mediating the benefits and complications of base therapy is warranted.
Collapse
|
3
|
Association of Increased Serum Leptin with Ameliorated Anemia and Malnutrition in Stage 5 Chronic Kidney Disease Patients after Parathyroidectomy. Sci Rep 2016; 6:27918. [PMID: 27307101 PMCID: PMC4910047 DOI: 10.1038/srep27918] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/26/2016] [Indexed: 01/11/2023] Open
Abstract
Leptin is an adipokine that regulates various metabolism, but its association with secondary hyperparathyroidism (SHPT), a clinical manifestation of chronic kidney disease-mineral and bone disorder (CKD-MBD), remains obscure. Parathyroidectomy (PTX) is recommended for severe SHPT patients. Here, the associations between circulating leptin and clinical characteristics in CKD patients were investigated. Effects of PTX on leptin production were analyzed in vivo and in vitro. Controls and CKD patients had approximate serum leptin levels in that a larger proportion of CKD patients with body mass index (BMI) <23 kg/m2. Serum leptin was related to anemia, albumin, and bone metabolism disorders in CKD patients. Lower intact parathyroid hormone (PTH) was related with higher leptin in PTX patients group. Severe SHPT inhibited uremia-enhanced leptin production in 3T3-L1 adipocytes, which was attenuated after PTX. High levels of PTH were found to reduce Akt phosphorylation and leptin production in vitro but high levels of calcium and phosphorus were not. Successful PTX was found to improve anemia and malnutrition in severe SHPT patients, and this was correlated with increased circulating leptin levels via up-regulated Akt signaling in adipocytes. These findings indicated the therapeutic potential of leptin and related target pathway for improving survival and quality of life in CKD.
Collapse
|