69 - Prevalence and Associations of Metabolic Acidosis in Pediatric Participants with Glomerular Disease in the NEPTUNE and CureGN Cohorts

Sunday, April 30, 2023

3:30 PM – 6:00 PM ET

Poster Number: 69
Publication Number: 69.351

Stella Kilduff, The Children's Hospital at Montefiore, Bronx, NY, United States; Frederick J. Kaskel, lbert Einstein College of Medicine, Bronx, NY, United States; Denver Brown, Children's National Health System, Washington, DC, United States; Michal Melamed, Albert Einstein College of Medicine, Bronx, NY, United States; Debbie S. Gipson, University of Michigan, Ann Arbor, MI, United States; Sean Eddy, University of Michigan Medical School, Ann Arbor, MI, United States; Yujie Wang, University of Michigan Medical School, Ann Arbor, MI, United States; Juhi Kumar, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; Matthew Abramowitz, Albert Einstein College of Medicine, Bronx, NY, United States; Kimberly J. Reidy, Children's Hospital at Montefiore, Bronxville, NY, United States

Presenting Author(s)

Stella Kilduff, MD

Pediatric Nephrology Fellow
The Children's Hospital at Montefiore
Bronx, New York, United States

Background:

Metabolic acidosis (MA) is associated with a more rapid decline of kidney function in cohorts of adults and children with chronic kidney disease (CKD). In the Chronic Kidney Disease in Children (CKiD) study, children with glomerular (compared to non-glomerular) CKD were more likely to have untreated acidosis. To date, no study has examined the prevalence of MA and factors related to serum bicarbonate in children with glomerular disease.

Objective:

To determine the prevalence and patient characteristics associated with MA in children with glomerular disease in the Nephrotic Syndrome Study Network (NEPTUNE) and Cure Glomerulonephropathy (Cure GN) cohorts. We hypothesized that acidosis would be more prevalent in patients with Focal Segmental Glomerulosclerosis (FSGS).

Design/Methods:

All children ages 1-17 years old, enrolled in the NEPTUNE or CureGN studies with at least one serum bicarbonate (total CO2) and eGFR measurement were included. Bivariate analysis and multivariable linear regression were performed to examine associations with baseline (at study enrollment) serum bicarbonate. MA was defined a serum bicarbonate < 22meq/L.

Results:

In the 786 participants eligible for study inclusion, the mean baseline serum bicarbonate was 24.8±3.15 meq/L (Table 1). 12.2% (n=96) of the cohort were acidotic and only 4% of acidotic patients were receiving alkali therapy. Participants with acidosis were younger (p< 0.0001) and had lower hemoglobin (p=0.005). Acidosis at baseline was not more prevalent in those with a diagnosis of FSGS. Each one-year older age was associated with 0.2 meq/L (95% CI: 0.14, 0.26) higher serum bicarbonate. Every 1g/dL higher hemoglobin was associated with a 0.23 meq/L (95% CI: 0.1, 0.4) higher serum bicarbonate. Diuretic use was associated with a 0.9 meq/L (95% CI: 0.09, 1.72) higher serum bicarbonate Underweight BMI percentile (compared to normal BMI) was associated with a 2.33 meq/L (95% CI: 0.47, 4.19) higher serum bicarbonate. In contrast, obesity BMI percentile was associated with a 0.61 meq/L (95%CI: -1.17, -0.05) lower serum bicarbonate. Patients with hypertension had a 1 meq/L (95%CI: -1.6, -0.4) lower serum bicarbonate. Baseline bicarbonate levels were not significantly associated with glomerular disease diagnosis or baseline eGFR (Table 2).

Conclusion(s):

Untreated MA is common in children with glomerular disease. Younger age, obesity and hypertension were associated with lower baseline serum bicarbonate. Ongoing analyses will examine the relationship between longitudinal acidosis, eGFR, and diagnosis.