OBJECTIVE: The MiniMed Continuous Glucose Monitoring System (CGMS) measures subcutaneous interstitial glucose levels that are calibrated against three or more fingerstick glucose levels daily. The objective of the present study was to examine whether the relationship between plasma and interstitial fluid glucose is altered by changes in plasma glucose and insulin levels and how such alterations might influence CGMS performance. RESEARCH DESIGN AND METHODS: Arterialized plasma glucose, sensor glucose, and interstitial fluid glucose were measured by microdialysis in 11 healthy subjects during a 1.0 mU. kg(-1). min(-1) stepped euglycemic-hypoglycemic-hyperglycemic (plasma glucose approximately 5, 3.1, and 8.6 mmol/l, respectively) insulin clamp that raised plasma insulin to approximately 360-390 pmol/l. RESULTS: When the CGMS was calibrated versus plasma glucose levels before insulin infusion, basal sensor and plasma glucose were similar (5.0 +/- 0.3 vs. 5.2 +/- 0.3 mmol/l, respectively); dialysate glucose was 3.3 +/- 0.9 mmol/l. During the hyperinsulinemic-euglycemia study (plasma glucose 4.9 +/- 0.3 mmol/l), dialysate glucose fell by 30-35%, accompanied by a significant reduction in sensor glucose (to 3.7 +/- 0.6 mmol/l; P < 0.001 vs. plasma). Subsequently, sensor levels remained lower than plasma values during mild hypoglycemia (2.5 +/- 0.6 vs. 3.1 +/- 0.3 mmol/l; P < 0.01) and during recovery from hypoglycemia (7.3 +/- 1.2 vs. 8.6 +/- 0.6; P < 0.01). However, when the CGMS was calibrated against plasma glucose levels before and during each step of the clamp, sensor glucose levels increased throughout the study and did not differ from plasma glucose values during hypoglycemia. CONCLUSIONS: Although hyperinsulinemia may contribute to modest discrepancies between plasma and sensor glucose levels, the CGMS is able to accurately track acute changes in plasma glucose when calibrated across a range of plasma glucose and insulin levels.
OBJECTIVE: The MiniMed Continuous Glucose Monitoring System (CGMS) measures subcutaneous interstitial glucose levels that are calibrated against three or more fingerstick glucose levels daily. The objective of the present study was to examine whether the relationship between plasma and interstitial fluid glucose is altered by changes in plasma glucose and insulin levels and how such alterations might influence CGMS performance. RESEARCH DESIGN AND METHODS: Arterialized plasma glucose, sensor glucose, and interstitial fluid glucose were measured by microdialysis in 11 healthy subjects during a 1.0 mU. kg(-1). min(-1) stepped euglycemic-hypoglycemic-hyperglycemic (plasma glucose approximately 5, 3.1, and 8.6 mmol/l, respectively) insulin clamp that raised plasma insulin to approximately 360-390 pmol/l. RESULTS: When the CGMS was calibrated versus plasma glucose levels before insulin infusion, basal sensor and plasma glucose were similar (5.0 +/- 0.3 vs. 5.2 +/- 0.3 mmol/l, respectively); dialysate glucose was 3.3 +/- 0.9 mmol/l. During the hyperinsulinemic-euglycemia study (plasma glucose 4.9 +/- 0.3 mmol/l), dialysate glucose fell by 30-35%, accompanied by a significant reduction in sensor glucose (to 3.7 +/- 0.6 mmol/l; P < 0.001 vs. plasma). Subsequently, sensor levels remained lower than plasma values during mild hypoglycemia (2.5 +/- 0.6 vs. 3.1 +/- 0.3 mmol/l; P < 0.01) and during recovery from hypoglycemia (7.3 +/- 1.2 vs. 8.6 +/- 0.6; P < 0.01). However, when the CGMS was calibrated against plasma glucose levels before and during each step of the clamp, sensor glucose levels increased throughout the study and did not differ from plasma glucose values during hypoglycemia. CONCLUSIONS: Although hyperinsulinemia may contribute to modest discrepancies between plasma and sensor glucose levels, the CGMS is able to accurately track acute changes in plasma glucose when calibrated across a range of plasma glucose and insulin levels.
Authors: Bruce A Buckingham; Craig Kollman; Roy Beck; Andrea Kalajian; Rosanna Fiallo-Scharer; Michael J Tansey; Larry A Fox; Darrell M Wilson; Stuart A Weinzimer; Katrina J Ruedy; William V Tamborlane Journal: Diabetes Technol Ther Date: 2006-06 Impact factor: 6.118
Authors: Ulrike Holzinger; Joanna Warszawska; Reinhard Kitzberger; Harald Herkner; Philipp G H Metnitz; Christian Madl Journal: Intensive Care Med Date: 2009-04-07 Impact factor: 17.440
Authors: Martin Ellmerer; Martin Haluzik; Jan Blaha; Jaromir Kremen; Stepan Svacina; Andreas Plasnik; Dimas Ikeoka; Manfred Bodenlenz; Lukas Schaupp; Johannes Plank; Thomas R Pieber Journal: Int J Endocrinol Date: 2009-05-26 Impact factor: 3.257
Authors: Stefan Lindpointner; Stefan Korsatko; Gerd Köhler; Hans Köhler; Roland Schaller; Lukas Schaupp; Martin Ellmerer; Thomas R Pieber; Werner Regittnig Journal: Diabetes Care Date: 2010-01-22 Impact factor: 17.152