Kidney Week

Abstract: SA-OR78

Low Serum Bicarbonate and Cardiovascular Disease Risk in Children with CKD

Session Information

• Pediatric Nephrology: Insights and Innovations
  October 26, 2024 | Location: Room 23, Convention Center
  Abstract Time: 05:20 PM - 05:30 PM

Category: Pediatric Nephrology

• 1900 Pediatric Nephrology

Authors

• Brown, Denver D., Children's National Hospital, Washington, District of Columbia, United States

Denver D. Brown, MD

• Roem, Jennifer, Johns Hopkins Medicine, Baltimore, Maryland, United States

Jennifer Roem, MS

• Reidy, Kimberly J., Children's Hospital at Montefiore, New York, New York, United States

Kimberly J. Reidy, MD

• Furth, Susan L., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Susan L. Furth, MD, PhD

• Warady, Bradley A., Children's Mercy Kansas City, Kansas City, Missouri, United States

Bradley A. Warady, MD

• Melamed, Michal L., NYU Langone Health, New York, New York, United States

Michal L. Melamed, MD

• Brady, Tammy McLoughlin, Johns Hopkins Medicine, Baltimore, Maryland, United States

Tammy McLoughlin Brady, MD, PhD

Background

In adults, metabolic acidosis (MA) has been linked to worse cardiovascular disease (CVD) outcomes but this association has not been studied in children with chronic kidney disease (CKD). We investigated if low serum bicarbonate (a MA surrogate) is associated with adverse CVD risk measurements in children with CKD.

Methods

This observational study included children ≥1 year of age enrolled in the Chronic Kidney Disease in Children (CKiD) study who had a baseline estimated glomerular filtration rate (eGFR) between 30-90 ml/min/1.73m² , ambulatory blood pressure measurement (ABPM) and left ventricular mass (LVM) data. Linear and logistic regression models were used to characterize associations between serum bicarbonate, ABPM, and LVM. As normative values for ABPM and LVM change in childhood, index measurements were calculated for ABPM and LVM (LVMI) based on participants’ age, sex, and height. Serum bicarbonate was analyzed continuously and categorized as <22mEq/L (low) and ≥22mEq/L (normal). Analyses were adjusted for age, sex, race, body mass index, CKD etiology group (nonglomerular and glomerular causes of CKD), and eGFR.

Results

The study population comprised 933 children- 696 with nonglomerular and 237 with glomerular CKD. The median age was 11 years old, 63% were males, and >50% were Caucasian. A total of 677 children were included in analyses that examined MA and ABPM and 819 children were included in analyses of MA and LVMI. In adjusted analyses, significant but opposite associations were noted between serum bicarbonate, ABPM index, and LVMI. Specifically, wake and sleep systolic and diastolic ABPM indices decreased with each 1meq/L decrease in serum bicarbonate level. However, LVMI increased with decreasing bicarbonate level: specifically, LVMI z-score increased 0.02 [0.01, 0.04] per 1mEq/L decrease in serum bicarbonate. The association with ABPM indices did not change when serum bicarbonate was categorized; however, low serum bicarbonate (<22mEq/L) was no longer significantly associated with LVMI once analyses were adjusted for eGFR.

Conclusion

Low serum bicarbonate was associated with decreasing systolic and diastolic ABPM indices, but increasing LVMI. Future studies will investigate if treatment of MA with sodium-based alkali therapies mitigates the associations between serum bicarbonate, ABPM, and LVMI.

Funding

• NIDDK Support