title: Measurement of glucose area under the curve using minimally invasive interstitial fluid extraction technology: evaluation of glucose monitoring concepts without blood sampling.
abstract: BACKGROUND
  Monitoring postprandial hyperglycemia is crucial in treating diabetes, although its dynamics make accurate monitoring difficult. We developed a new technology for monitoring postprandial hyperglycemia using interstitial fluid (ISF) extraction technology without blood sampling. The glucose area under the curve (AUC) using this system was measured as accumulated ISF glucose (IG) with simultaneous calibration with sodium ions. The objective of this study was to evaluate this technological concept in healthy individuals.
  
  
  METHODS
  Minimally invasive ISF extraction technology (MIET) comprises two steps: pretreatment with microneedles and ISF accumulation over a specific time by contact with a solvent. The correlation between glucose and sodium ion levels using MIET was evaluated in 12 subjects with stable blood glucose (BG) levels during fasting. BG and IG time courses were evaluated in three subjects to confirm their relationship while BG was fluctuating. Furthermore, the accuracy of glucose AUC measurements by MIET was evaluated several hours after a meal in 30 subjects.
  
  
  RESULTS
  A high correlation was observed between glucose and sodium ion levels when BG levels were stable (R=0.87), indicating that sodium ion is a good internal standard for calibration. The variation in IG and BG with MIET was similar, indicating that IG is an adequate substitute for BG. Finally, we showed a strong correlation (R=0.92) between IG-AUC and BG-AUC after a meal.
  
  
  CONCLUSIONS
  These findings validate the adequacy of glucose AUC measurements using MIET. Monitoring glucose using MIET without blood sampling may be beneficial to patients with diabetes.
authors.affiliation: Central Research Laboratories, Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, Japan. Sato.Toshiyuki@sysmex.co.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sato
authors.forename: Seiki
authors.initials: S
authors.lastname: Okada
authors.forename: Kei
authors.initials: K
authors.lastname: Hagino
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Asakura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kikkawa
authors.forename: Junko
authors.initials: J
authors.lastname: Kojima
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Maekawa
authors.forename: Kazuki
authors.initials: K
authors.lastname: Isobe
authors.forename: Reona
authors.initials: R
authors.lastname: Koike
authors.forename: Hiromu
authors.initials: H
authors.lastname: Nakajima
authors.forename: Kaoru
authors.initials: K
authors.lastname: Asano
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000097:blood / Q000378:metabolism*; D045604:Extracellular Fluid / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D019518:Postprandial Period; D012964:Sodium / Q000032:analysis; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D012964:Sodium; D005947:Glucose