Original Article | Published:

Epidemiology

Association between the markers of metabolic acid load and higher all-cause and cardiovascular mortality in a general population with preserved renal function

Hypertension Research volume 38, pages 433438 (2015) | Download Citation

Abstract

Although metabolic acid load has been associated with many well-known risk factors for mortality, its clinical implications are not yet clear. To evaluate the association between biomarkers of metabolic acid load, such as serum bicarbonate, serum anion gap and urine pH and mortality, we analyzed the health records of 31 590 adults who underwent a health screening between January 2001 and December 2010 and had an estimated glomerular filtration rate 60 ml min−1 per 1.73 m2. Urine pH was measured by a dipstick test performed on fast morning urine sample and categorized as acidic (urine pH 5.5), neutral and alkaline (urine pH 8.0). Using the Cox proportional hazard model, the adjusted hazard ratio (aHR) of all-cause mortality of the lowest quartile of serum bicarbonate was 1.460 (95% confidence interval (CI) 1.068–1.995) compared with the highest quartile, after a median follow-up of 93 months. The aHRs of cardiovascular and cancer mortality of the lowest quartile of serum bicarbonate were 2.647 (95% CI 1.148–6.103) and 1.604 (95% CI 1.024–2.513), respectively, compared with the highest quartile. Acidic and neutral urine pH were significantly associated with a higher all-cause mortality (aHR 2.550, 95% CI 1.316–4.935; aHR 2.376 95% CI 1.254–4.501, respectively), compared with an alkaline urine pH. In conclusion, higher metabolic acid load was associated with an increased all-cause and cardiovascular mortality in a healthy population. The association between metabolic acid load and mortality and the causality of the relationship need to be confirmed.

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Acknowledgements

This work was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Korean government (Ministry of Education and Science Technology) (2010-0028631).

Author Contributions

MP and HJY designed the study, analyzed and interpreted the data and prepared the manuscript. SJJ and SY collected and analyzed the data. JMY designed the study and collected the data. All authors reviewed and edited the manuscript and approved the final version of the manuscript.

Author information

Affiliations

  1. Department of Family Medicine, Seoul National University Hospital, Seoul, Republic of Korea

    • Minseon Park
    •  & Jae Moon Yun
  2. Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, Republic of Korea

    • Sung Jae Jung
    • , Seoyoung Yoon
    •  & Hyung-Jin Yoon

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The authors declare no conflict of interest.

Corresponding author

Correspondence to Hyung-Jin Yoon.

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DOI

https://doi.org/10.1038/hr.2015.23

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