title: Detection of hypoglycemia with continuous interstitial and traditional blood glucose monitoring using the FreeStyle Navigator Continuous Glucose Monitoring System.
abstract: BACKGROUND
  The objective of the analysis was to compare detection of hypoglycemic episodes (glucose <70 mg/dL lasting >15 min) with the FreeStyle Navigator Continuous Glucose Monitoring System (FSN-CGM) (Abbott Diabetes Care, Alameda, CA) alarms to detection with traditional finger stick testing at an average frequency of eight tests per day.
  
  
  METHODS
  The performance of FSN-CGM alarms was evaluated in a clinic setting using 58 subjects with type 1 diabetes mellitus (T1DM) monitoring interstitial glucose concentration over a 5-day period compared to reference YSI measurements (instrument manufactured by YSI, Yellow Springs, OH) at 15-min intervals. Finger stick glucose testing was evaluated in the home environment with 91 subjects with TIDM monitoring with the blood glucose meter integrated into the FreeStyle Navigator (FSN-BG) over a 20-day period. The reference was FSN-CGM with results masked from the subjects. Blood glucose values <=85 mg/dL were considered the optimal treatment level to avoid or reverse hypoglycemia.
  
  
  RESULTS
  With a threshold alarm setting of 85 mg/dL, 90.6% of hypoglycemic episodes were detected within +/- 30 min by FSN-CGM in the clinic study. When the alarm was activated, YSI glucose was <= 85 mg/dL 77.2% of the time. In the home environment, the average FSN-BG testing frequency was 7.9 tests per day. Hypoglycemia was verified within +/- 30 min by FSN-BG measurements <= 85 mg/dL at a rate of 27.5%.
  
  
  CONCLUSIONS
  Even with a high rate of FSN-BG testing, hypoglycemia detected by FSN-CGM was verified by patients with T1DM very infrequently. A high rate of hypoglycemia detection with a moderate rate of unnecessary alarms can be attained using FSN-CGM.
authors.affiliation: Abbott Diabetes Care, Alameda, California, USA. geoff.mcgarraugh@abbott.com
authors.forename: Geoffrey
authors.initials: G
authors.lastname: McGarraugh
authors.forename: Richard
authors.initials: R
authors.lastname: Bergenstal
mesh_terms: D000293:Adolescent; D000328:Adult; D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose