Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Dec;8(12):2034-42.
doi: 10.2215/CJN.03600413. Epub 2013 Sep 19.

Dietary acid, age, and serum bicarbonate levels among adults in the United States

Afolarin Amodu  1 , Matthew K Abramowitz
Affiliations

Dietary acid, age, and serum bicarbonate levels among adults in the United States

Afolarin Amodu et al. Clin J Am Soc Nephrol. 2013 Dec.

Abstract

Background and objectives: Greater dietary acid has been associated with lower serum bicarbonate levels in patients with CKD. Whether this association extends to the general population and if it is modified by age are unknown.

Design, setting, participants, & measurements: This study examined the association of the dietary acid load, estimated by net endogenous acid production, with serum bicarbonate levels in adult participants in the National Health and Nutrition Examination Survey 1999-2004.

Results: The mean serum bicarbonate was 24.9 mEq/L (SEM=0.1), and the mean estimated net endogenous acid production was 57.4 mEq/d (SEM=0.4). Serum bicarbonate was linearly associated with age, such that the oldest participants had the highest serum bicarbonate levels. After multivariable adjustment, participants in the highest quartile of net endogenous acid production had 0.40 mEq/L (95% confidence interval, -0.55 to -0.26) lower serum bicarbonate and a 33% (95% confidence interval, 3 to 72) higher likelihood of acidosis compared with those participants in the lowest quartile. There was a significant interaction by age of the association of net endogenous acid production with serum bicarbonate (P=0.005). Among participants 20-39, 40-59, and ≥60 years old, those participants in the highest net endogenous acid production quartile had 0.26 (95% confidence interval, -0.49 to -0.03), 0.60 (95% confidence interval, -0.92 to -0.29), and 0.49 (95% confidence interval, -0.84 to -0.14) mEq/L lower serum bicarbonate, respectively, compared with participants in the lowest quartile.

Conclusion: Greater dietary acid is associated with lower serum bicarbonate in the general US population, and the magnitude of this association is greater among middle-aged and elderly persons than younger adults.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Association of estimated net endogenous acid production (NEAP; mEq/d) with age in 9781 participants of the National Health and Nutrition Examination Survey 1999–2004. Each bar represents an NEAP quartile. Error bars represent SEMs.
Figure 2.
Figure 2.
Mean serum bicarbonate levels across age categories, overall, and within quartiles of estimated net endogenous acid production (NEAP; mEq/d) in 9781 participants of the National Health and Nutrition Examination Survey 1999–2004. Individual lines represent the overall population and individual NEAP quartiles. Within each age category, the mean serum bicarbonate is listed for the highest and lowest quartile of NEAP.
See this image and copyright information in PMC

References

    1. Kraut JA, Madias NE: Consequences and therapy of the metabolic acidosis of chronic kidney disease. Pediatr Nephrol 26: 19–28, 2011 - PMC - PubMed
    1. de Brito-Ashurst I, Varagunam M, Raftery MJ, Yaqoob MM: Bicarbonate supplementation slows progression of CKD and improves nutritional status. J Am Soc Nephrol 20: 2075–2084, 2009 - PMC - PubMed
    1. Ballmer PE, McNurlan MA, Hulter HN, Anderson SE, Garlick PJ, Krapf R: Chronic metabolic acidosis decreases albumin synthesis and induces negative nitrogen balance in humans. J Clin Invest 95: 39–45, 1995 - PMC - PubMed
    1. Frassetto L, Morris RC, Jr, Sellmeyer DE, Todd K, Sebastian A: Diet, evolution and aging—the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet. Eur J Nutr 40: 200–213, 2001 - PubMed
    1. Macdonald HM, New SA, Fraser WD, Campbell MK, Reid DM: Low dietary potassium intakes and high dietary estimates of net endogenous acid production are associated with low bone mineral density in premenopausal women and increased markers of bone resorption in postmenopausal women. Am J Clin Nutr 81: 923–933, 2005 - PubMed

Publication types

MeSH terms