Age and systemic acid-base equilibrium: analysis of published data

J Gerontol A Biol Sci Med Sci. 1996 Jan;51(1):B91-9. doi: 10.1093/gerona/51a.1.b91.

Abstract

To investigate whether systemic acid-base equilibrium changes with aging in normal adult humans, we reviewed published articles reporting the acid-base composition of arterial, arterialized venous, or capillary blood in age-identified healthy subjects. We extracted or calculated blood hydrogen ion concentration ([H+]), plasma bicarbonate concentration ([HCO3(-)]), blood PCO2, and age, and computed a total of 61 age-group means, distributed among eight 10-year intervals from age 20 to 100 years. Using linear regression analysis, we found that with increasing age, there is a significant increase in the steady-state blood [H+] (p < .001), and reduction in steady-state plasma [HCO3(-)] (p < .001), indicative of a progressively worsening low-level metabolic acidosis. Blood PCO2 decreased with age (p < .05), in keeping with the expected respiratory adaptation to metabolic acidosis. Such age-related increasing metabolic acidosis may reflect in part the normal decline of renal function with increasing age. The role of age-related metabolic acidosis in the pathogenesis of the degenerative diseases of aging warrants consideration.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acid-Base Equilibrium / physiology*
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / physiology*
  • Diet
  • Female
  • Homeostasis
  • Humans
  • Kidney / physiology
  • Male
  • Middle Aged