Piyawan Kittiskulnam1,2,3, Somrath Srijaruneruang3,4, Adhisabandh Chulakadabba5, Nintita Sripaiboonkij Thokanit6, Kearkiat Praditpornsilpa2,3, Kriang Tungsanga3, Somchai Eiam-Ong7,8. 1. Division of Internal Medicine-Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand. 2. Special Task force for Activating Research in Renal Nutrition (Renal Nutrition Research Group), Office of Research Affairs, Chulalongkorn University, Bangkok, Thailand. 3. Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. 4. Department of Medicine, Vichaiyut Medical Center, Bangkok, Thailand. 5. Department of Surgery, Faculty of Medicine, Chulalongkorn University and Queen Sirikit Centre for Breast Cancer, Thai Red Cross Society, Bangkok, Thailand. 6. Ramathibodi Comprehensive Cancer Center, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. 7. Special Task force for Activating Research in Renal Nutrition (Renal Nutrition Research Group), Office of Research Affairs, Chulalongkorn University, Bangkok, Thailand, somchai80754@yahoo.com. 8. Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, somchai80754@yahoo.com.
Abstract
BACKGROUND: Treatment of metabolic acidosis to target the higher serum bicarbonate level than guideline recommendation may downregulate muscle protein degradation and improve renal function among chronic kidney disease (CKD) patients. We conducted a study to test the effects of increased serum bicarbonate level on muscle parameters, nutrition, and renal function in pre-dialysis CKD patients. METHODS: This was a randomized, controlled study. CKD stage 3-4 patients with serum HCO3- <22 mEq/L were randomized to either receive oral sodium bicarbonate with high target bicarbonate level of 25 ± 1 or standard level of 22 ± 1 mEq/L as control group using protocol-based titration of dosage adjustment. The changes of muscle mass measured by bioelectrical impedance analysis (BIA), muscle strength by hand grip dynamometer, estimated glomerular filtration rate (eGFR) using CKD-Epidemiology Collaboration equation, nutritional markers, and muscle-related biomarkers were determined. Data at baseline and after 4 months of sodium bicarbonate supplementation were compared between groups using Student t test or chi-square test as appropriate. RESULTS: Forty-two patients completed the study (n = 21 per group). The mean age and eGFR were 61.2 ± 9.8 years and 32.4 ± 14.1 mL/min respectively. Serum bicarbonate levels at baseline were 21.0 ± 2.1 mEq/L. Baseline data including sex, diabetes, serum bicarbonate level, creatinine, and blood pressure were similar. After 4 months of treatment, the average serum bicarbonate levels in both groups were 24.0 ± 1.4 and 20.7 ± 2.3 mEq/L (p < 0.001). Both BIA-derived total-body muscle mass and appendicular lean balance were increased at 4 months in the higher bicarbonate group (26.0 ± 5.3 to 26.7 ± 5.5 kg, p = 0.04 and 19.8 ± 4.1 to 20.7 ± 4.4 kg, p = 0.06, respectively) despite comparable body weight and protein intake. Patients in the high bicarbonate group had a significant reduction of plasma myostatin levels, a surrogate of muscle degradation, at the study exit after adjusting for baseline values (-3,137.8; 95% CI -6,235.3 to -40.4 pg/mL, p= 0.04), but unaltered insulin-like growth factor-1 level, as the mediator of muscle cell growth, (141 [106-156] to 110 [87-144] ng/mL, p = 0.13) compared to the control group. Muscle strength, eGFR as well as serum prealbumin were not significantly different between 2 groups (p > 0.05). Neither worsening hypertension nor congestive heart failure was found throughout the study. CONCLUSION:Bicarbonate supplementation to achieve the serum level ∼24 mEq/L demonstrates better muscle mass preservation in patients with pre-dialysis CKD. The impact of alkaline therapy on renal function may require a longer period of study.
RCT Entities:
BACKGROUND: Treatment of metabolic acidosis to target the higher serum bicarbonate level than guideline recommendation may downregulate muscle protein degradation and improve renal function among chronic kidney disease (CKD) patients. We conducted a study to test the effects of increased serum bicarbonate level on muscle parameters, nutrition, and renal function in pre-dialysis CKDpatients. METHODS: This was a randomized, controlled study. CKD stage 3-4 patients with serum HCO3- <22 mEq/L were randomized to either receive oral sodium bicarbonate with high target bicarbonate level of 25 ± 1 or standard level of 22 ± 1 mEq/L as control group using protocol-based titration of dosage adjustment. The changes of muscle mass measured by bioelectrical impedance analysis (BIA), muscle strength by hand grip dynamometer, estimated glomerular filtration rate (eGFR) using CKD-Epidemiology Collaboration equation, nutritional markers, and muscle-related biomarkers were determined. Data at baseline and after 4 months of sodium bicarbonate supplementation were compared between groups using Student t test or chi-square test as appropriate. RESULTS: Forty-two patients completed the study (n = 21 per group). The mean age and eGFR were 61.2 ± 9.8 years and 32.4 ± 14.1 mL/min respectively. Serum bicarbonate levels at baseline were 21.0 ± 2.1 mEq/L. Baseline data including sex, diabetes, serum bicarbonate level, creatinine, and blood pressure were similar. After 4 months of treatment, the average serum bicarbonate levels in both groups were 24.0 ± 1.4 and 20.7 ± 2.3 mEq/L (p < 0.001). Both BIA-derived total-body muscle mass and appendicular lean balance were increased at 4 months in the higher bicarbonate group (26.0 ± 5.3 to 26.7 ± 5.5 kg, p = 0.04 and 19.8 ± 4.1 to 20.7 ± 4.4 kg, p = 0.06, respectively) despite comparable body weight and protein intake. Patients in the high bicarbonate group had a significant reduction of plasma myostatin levels, a surrogate of muscle degradation, at the study exit after adjusting for baseline values (-3,137.8; 95% CI -6,235.3 to -40.4 pg/mL, p= 0.04), but unaltered insulin-like growth factor-1 level, as the mediator of muscle cell growth, (141 [106-156] to 110 [87-144] ng/mL, p = 0.13) compared to the control group. Muscle strength, eGFR as well as serum prealbumin were not significantly different between 2 groups (p > 0.05). Neither worsening hypertension nor congestive heart failure was found throughout the study. CONCLUSION:Bicarbonate supplementation to achieve the serum level ∼24 mEq/L demonstrates better muscle mass preservation in patients with pre-dialysis CKD. The impact of alkaline therapy on renal function may require a longer period of study.
Authors: Mary Courtney Moore; Katie C Coate; Melanie Scott; Guillaume Kraft; James E Vath; Thomas E Hughes; Ben Farmer; Alan D Cherrington Journal: Am J Physiol Endocrinol Metab Date: 2020-01-28 Impact factor: 4.310