IJMS, Vol. 22, Pages 11111: Possibility of Venous Serum Clâˆ` Concentration ([Clâˆ`]s) as a Marker for Human Metabolic Status: Correlation of [Clâˆ`]s to Age, Fasting Blood Sugar (FBS), and Glycated Hemoglobin (HbA1c) (International Journal of Molecular Sciences)

The HCO3âˆ` concentration in venous serum ([HCO3âˆ`]s) is a factor commonly used for detecting the body pH and metabolic conditions. To exactly detect [HCO3âˆ`]s, the venous CO2 pressure should be kept as it is in the vein. The [HCO3âˆ`]s measurement is technically complicated to apply for huge numbers of almost heathy persons taking only basic medical examinations. The summation of [HCO3âˆ`]s and the venous serum Clâˆ` concentration ([Clâˆ`]s) is approximately constant; therefore, we studied if [Clâˆ`]s could be a marker detecting metabolic conditions instead of [HCO3âˆ`]s. Venous blood was obtained from persons taking basic medical examinations (the number of persons = 107,630). Older persons showed higher values of [Clâˆ`]s, fasting blood sugar (FBS), and glycated hemoglobin (HbA1c) than younger ones. [Clâˆ`]s showed positive correlation to age and negative correlation to FBS and HBA1c. The negative correlation of [Clâˆ`]s to FBS/HbA1c was obvious in persons with high FBS/HbA1c, leading us to an idea that persons with high FBS/HbA1c show high [HCO3âˆ`]s, which might be caused by low activity of carbonic anhydrase in the lung observed in persons with diabetes mellitus under acidotic conditions. Taken together, an easily measured serum electrolyte, [Clâˆ`]s, could be a useful marker estimating metabolic conditions.