TY - JOUR
T1 - Obesity and the Risk of Low Bicarbonate
T2 - A Cohort Study
AU - Lambert, Douglas C.
AU - Abramowitz, Matthew K.
N1 - Funding Information:
Dr Abramowitz was supported by K23DK099438 from the National Institutes of Health .
Funding Information:
Douglas C. Lambert, MD, and Matthew K. Abramowitz, MD, MS. Research idea and study design: DCL, MKA; data acquisition: DCL; data analysis and interpretation: DCL, MKA; statistical analysis: DCL, MKA: supervision or mentorship: MKA. Each author contributed important intellectual content during manuscript drafting or revision and accepts accountability for the overall work by ensuring that questions pertaining to the accuracy or integrity of any portion of the work are appropriately investigated and resolved. Dr Abramowitz was supported by K23DK099438 from the National Institutes of Health. Dr Abramowitz has received consulting fees from Tricida, Inc. Dr Lambert declares that he has no relevant financial interests. Data from this project were presented as an online poster abstract at the Society of General Internal Medicine 2020, May 6-9, 2020, virtual meeting. Received July 10, 2020. Evaluated by 2 external peer reviewers, with direct editorial input from the Statistical Editor, an Associate Editor, and the Editor-in-Chief. Accepted in revised form February 15, 2021.
Publisher Copyright:
© 2021 The Authors
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Rationale & Objective: Acid retention may occur in the absence of overt metabolic acidosis; thus it is important to identify populations at risk. Because obesity may alter renal acid-base handling, we sought to determine whether overweight and obesity are associated with increased risk for low serum bicarbonate levels, suggesting metabolic acidosis. Study Design: Retrospective cohort study. Setting & Participants: Adult patients (n = 96,147) visiting outpatient clinics in the Bronx, NY, between January 1, 2010, and December 31, 2015. Predictor: Body mass index (BMI). Outcome: Low serum bicarbonate level (≤23 mEq/L). Analytical Approach: Longitudinal analyses were conducted using mixed-effects models to examine associations of BMI with serum bicarbonate levels over time and Cox proportional hazards models to examine associations of BMI with incident low bicarbonate levels. Results: During a median follow-up of 4.4 (interquartile range, 2.3-6.3) years, patients had a median of 8 serum bicarbonate measurements and 34,539 patients developed low bicarbonate levels. Higher BMI was associated with progressively lower serum bicarbonate levels, with attenuation of the association in the highest BMI groups, suggesting a J-shaped relationship. Compared with the reference group (BMI, 18.5 to <25 kg.m2), patients with BMIs of 25 to <30, 30 to <35, 35 to <40, and ≥40 kg/m2 had HRs for incident low bicarbonate levels of 1.10 (95% CI, 1.05-1.14), 1.16 (95% CI, 1.11-1.21), 1.20 (95% CI, 1.14-1.26), and 1.15 (95% CI, 1.09-1.22). Results were similar after adjustment for serum urea nitrogen level and exclusion of patients with diabetes, hypertension, or estimated glomerular filtration rates < 60 mL/min/1.73 m2. Limitations: Arterial pH measurements were unavailable. Conclusions: Higher BMI is independently associated with progressively greater risk for developing low serum bicarbonate levels, indicating likely metabolic acidosis. Further research should explore the causes of low bicarbonate levels in patients with overweight and obesity.
AB - Rationale & Objective: Acid retention may occur in the absence of overt metabolic acidosis; thus it is important to identify populations at risk. Because obesity may alter renal acid-base handling, we sought to determine whether overweight and obesity are associated with increased risk for low serum bicarbonate levels, suggesting metabolic acidosis. Study Design: Retrospective cohort study. Setting & Participants: Adult patients (n = 96,147) visiting outpatient clinics in the Bronx, NY, between January 1, 2010, and December 31, 2015. Predictor: Body mass index (BMI). Outcome: Low serum bicarbonate level (≤23 mEq/L). Analytical Approach: Longitudinal analyses were conducted using mixed-effects models to examine associations of BMI with serum bicarbonate levels over time and Cox proportional hazards models to examine associations of BMI with incident low bicarbonate levels. Results: During a median follow-up of 4.4 (interquartile range, 2.3-6.3) years, patients had a median of 8 serum bicarbonate measurements and 34,539 patients developed low bicarbonate levels. Higher BMI was associated with progressively lower serum bicarbonate levels, with attenuation of the association in the highest BMI groups, suggesting a J-shaped relationship. Compared with the reference group (BMI, 18.5 to <25 kg.m2), patients with BMIs of 25 to <30, 30 to <35, 35 to <40, and ≥40 kg/m2 had HRs for incident low bicarbonate levels of 1.10 (95% CI, 1.05-1.14), 1.16 (95% CI, 1.11-1.21), 1.20 (95% CI, 1.14-1.26), and 1.15 (95% CI, 1.09-1.22). Results were similar after adjustment for serum urea nitrogen level and exclusion of patients with diabetes, hypertension, or estimated glomerular filtration rates < 60 mL/min/1.73 m2. Limitations: Arterial pH measurements were unavailable. Conclusions: Higher BMI is independently associated with progressively greater risk for developing low serum bicarbonate levels, indicating likely metabolic acidosis. Further research should explore the causes of low bicarbonate levels in patients with overweight and obesity.
KW - Obesity
KW - acid-base
KW - bicarbonate
KW - body mass index
KW - insulin resistance
KW - metabolic acidosis
KW - overweight
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U2 - 10.1016/j.xkme.2021.02.006
DO - 10.1016/j.xkme.2021.02.006
M3 - Article
AN - SCOPUS:85106236800
SN - 2590-0595
VL - 3
SP - 498-506.e1
JO - Kidney Medicine
JF - Kidney Medicine
IS - 4
ER -
