title: Effect of acetaminophen on the accuracy of glucose measurements obtained with the GlucoWatch biographer.
abstract: BACKGROUND
  Improved glycemic control significantly reduces long-term microvascular complications of diabetes mellitus associated with chronic hyperglycemia. The GlucoWatch biographer is designed to facilitate intensive diabetes management by providing automatic, frequent, and noninvasive glucose readings up to three times per hour for as long as 12 hours.
  
  
  METHODS
  The device extracts glucose through intact skin using reverse iontophoresis and measures the extracted glucose with an electrochemical biosensor. A clinical trial was performed to assess the effect of acetaminophen, a potential interference for traditional blood glucose meters, on the accuracy of the GlucoWatch biographer in adult subjects with diabetes (n = 18). One thousand milligram doses of acetaminophen were administered to subjects in two groups: one to achieve Cmax (peak acetominophen concentration) at the time of biographer calibration and the other to achieve Cmax during the measurement period. The biographer readings were compared to serial fingerstick blood glucose measurements.
  
  
  RESULTS
  Time profiles over 9 hours show close tracking of the biographer glucose results with fingerstick blood glucose measurements for all groups. The mean difference between the two measurements is between 8 and 12 mg/dL for all groups. The mean absolute value of the relative difference is less than 20%, and more than 93% of the points were in the clinically acceptable (A+B) region of the Clarke Error Grid. No statistically significant differences were found for any accuracy measurement across all groups.
  
  
  CONCLUSIONS
  The GlucoWatch Biographer provides frequent measurements of glucose over a 12-hour period with high accuracy. No effect of therapeutic dosage of acetaminophen on the accuracy of the glucose readings was found.
authors.affiliation: Cygnus, Inc, Redwood City, California 94063, USA. Tierney@cygn.com
authors.forename: M J
authors.initials: MJ
authors.lastname: Tierney
authors.forename: S
authors.initials: S
authors.lastname: Garg
authors.forename: N R
authors.initials: NR
authors.lastname: Ackerman
authors.forename: S J
authors.initials: SJ
authors.lastname: Fermi
authors.forename: J
authors.initials: J
authors.lastname: Kennedy
authors.forename: M
authors.initials: M
authors.lastname: Lopatin
authors.forename: R O
authors.initials: RO
authors.lastname: Potts
authors.forename: J A
authors.initials: JA
authors.lastname: Tamada
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000328:Adult; D000704:Analysis of Variance; D001331:Automation; D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D004563:Electrochemistry; D004867:Equipment Design; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors; D014481:United States; D044465:White People
chemical_list: D001786:Blood Glucose; D000082:Acetaminophen