Table 1.

Terminology and calculations of the four urine anion gap measurements in this study

TermCalculation, mEq/d
UAGUrine (sodium + potassium) − (chloride)
UAGSO4Urine (sodium + potassium) − (chloride + sulfate)
UAGPO4Urine (sodium + potassium) − (chloride + phosphate)
UAGPLUSUrine (sodium + potassium) − (chloride + phosphate + sulfate)
  • Because urine pH was not available, the milliequivalents of phosphate were calculated using urine pH of 5.5 in all participants. UAG, urine anion gap; UAGSO4, urine anion gap with inclusion of urine sulfate; UAGPO4, urine anion gap with inclusion of urine phosphate; UAGPLUS, urine anion gap with inclusion of urine phosphate and sulfate.