Continuous Glucose Monitoring System Values Research Articles

Spontaneous Hypoglycaemia due to Insulin Autoimmune Syndrome in Six Cases, Response to Steroid Therapy and Rituximab.

Dr. Hirata of Japan first described insulin autoimmune syndrome (IAS) in 1970. Seven hundred ninety-five cases of this rare syndrome have been reported from Japan and China and 29 from India. IAS has the following characteristic features 1) severe spontaneous attacks of hyperinsulinemic hypoglycaemia, 2) high total immunoreactive insulin levels, 3) elevated insulin autoantibody (IAA) titres, 4) no prior exposure to exogenous insulin, and 5) no pathological abnormalities of the pancreatic islet cells. We treated six cases of IAS with high doses of prednisolone for 4-6 weeks and then gradually reduced the doses. Diagnosis of IAS was established by documenting Whipple's triad of symptoms and signs of hypoglycaemia, blood sugar <55 mg/dl, improvement of symptoms with dextrose infusion, inappropriately increased insulin levels >3 uU/ml, C-peptide levels >0.6 ng/ml, and increased titres of anti-insulin autoantibodies. Insulinoma and non-pancreatic tumours were ruled out by CECT (contrast-enhanced computerised tomography) or MRI (magnetic resonance imaging) of the abdomen and if necessary endoscopic ultrasonography and gallium 68 Dotanoc PET (positron enhanced tomography). Autoimmune screening and serum electrophoresis were done to rule out multiple myeloma. Monitoring of the patient's blood sugars was done by the laboratory, glucometer readings, and a freestyle libre glucose monitoring system. Remission of hypoglycaemic episodes, hyperglycaemic episodes, and marked reduction of serum insulin and insulin autoantibodies in four out of six patients with diet therapy and steroids. Two patients resistant to steroids were treated with rituximab successfully. Patient 6 developed serious complications of cytomegalovirus and Pneumocystis carnii after rituximab, which were treated successfully. A careful history including recent infections, medications, and vaccinations provides vital clues in the evaluation. An increased awareness of IAS will prevent unnecessary and costly investigations and surgery. Although it is often self-remitting, steroids are contributory in severe cases. Immunosuppressives are used successfully in cases refractory to steroids. Continuous glucose monitoring system (CGMS), by freestyle libre glucose monitoring system, provided real-time blood sugar values, total time in hypoglycaemia, and total time in the range (TIR), which proved very valuable in managing IAS patients. Low CGMS values should be corroborated clinically and with laboratory or glucometer values.

Abstract #1397695: Use of Continuous Glucose Monitoring to Solve the Mystery of Pseudohypoglycemia

Hypoglycemia (glucose < 55 mg/dL) is uncommon in people without diabetes. Routine monitoring of blood glucose in hospitalized patients usually is performed by fingerstick point of care (POC) glucose testing via glucometer as a measure of capillary whole-blood glucose, correlating with venous plasma glucose. Pseudohypoglycemia is a consideration when POC glucose is low but plasma blood glucose is normal range. It can occur in the setting of impaired peripheral perfusion, such as in patients with Raynaud’s disease, shock, or peripheral vascular disease (PVD). A 63-year-old female was admitted for evaluation of uncontrolled hypertension. Her medical history was significant for previous myocardial infarction, atrial fibrillation, and heart failure with preserved ejection fraction. She had no history of Raynaud's phenomenon, diabetes (HbA1C 5.1%), or known PVD. During hospitalization, she had symptoms of anxiety, diaphoresis, tremors, nausea, forgetfulness, dizziness. POC glucose was 37 mg/dL and the patient was promptly treated with IV dextrose, negating a blood draw for a confirmatory venous plasma glucose. Several similar episodes occurred, even while on dextrose infusion prompting a hypoglycemia laboratory work-up. Off of dextrose, her POC glucose dropped to <50 mg/dL with insulin 97.7 uIU/mL, C-peptide 12.3 ng/mL and proinsulin of 77 pmol/L. However venous glucose was 173 ng/mL and thought to reflect treatment with dextrose prior to the blood draw. A second time, POC glucose was <50 ng/mL with insulin 48.9 uIU/mL and C-peptide 6.0 ng/mL which could support hyperinsulinemia but, again, venous plasma glucose was normal (113 mg/dL). Anti-diabetic medication and insulin antibody screening were negative. A continuous glucose monitoring system (CGMS) was placed on her abdomen to provide alternative peripheral glucose data. The patient manifested glucoses of 32/15/21 mg/dL by glucometer while simultaneous CGMS values were 110/126/156 mg/dL, confirming pseudohypoglycemia. In nondiabetic patients, hypoglycemia fulfilling Whipple’s triad be documented prior to initiating the complex evaluation for causes of hypoglycemia. Our patient is unusual because she did not have usual causes of pseudohypoglycemia such as Raynaud’s disease, diabetes, shock, or PVD. The inaccuracy of POC glucose measurements in patients with impaired microperfusion should be considered when the data are incongruent, as this can cause unnecessary investigations and prolonged length of stay. Should alternative blood glucose monitoring be required in these patients, CGM is a valuable technology.

Reliability of continuous glucose monitoring system in the inpatient setting

Aims/HypothesisHyperglycemia and hypoglycemia are associated with increased morbidity and mortality in the inpatient setting. Standard point of care capillary glucose testing (POCT) is commonly used in hospitalized patients to monitor their glucose levels. The goal of this study was to examine the relationships between the glucose readings obtained by a continuous glucose monitoring system (CGMS) (Freestyle Libre) and the capillary blood glucose results obtained by the inpatient glucose POCT meter (Accuchek Inform II) as well as between CGMS readings and the serum glucose values obtained by the hospital laboratory. Study participants had either primary or secondary diagnosis of diabetes mellitus and were admitted to non-critical units. We hypothesized that there exists an acceptable agreement between the capillary blood glucose results obtained by the inpatient glucose POCT meter (Accuchek Inform II) and the readings obtained by the CGMS (Freestyle Libre); and that there exists an acceptable agreement between the serum glucose levels and the glucose values obtained by the CGMS. MethodsThis was an Institutional Review Board approved prospective cohort study for the non– critical inpatient setting. Fifty-two hospitalized patients with diabetes were recruited. After informed consent was obtained, patients were instructed on the application and use of the CGMS. The data were assessed using a standard regression analysis and modified Bland Altman analysis. All analyses were conducted using SAS, release 3.8 Enterprise Edition (SAS Institute Inc., Cary, NC). ResultsFifty-two subjects recruited into the study represented a sample of convenience. There were a total of 467 AccuChek-Libre pairs, The regression analysis showed a negative bias between.Libre and AccuChek, R2 = 0.83, with Libre glucose readings on average being lower than those of AccuChek. Using Bland-Altman analysis, 42% of the 467 Libre-AccuChek pairs had a difference in glucose reading more than 15%. Mean absolute relative difference (MARD) between Libre and AccuChek was 15.6%; mean relative difference (MRD) between Libre and AccuChek was −11.4%.The regression analysis showed a negative bias between Libre and serum glucose, R2 = 0.89. Using Bland Altman analysis, 36% of the 44 Libre-serum pairs had a difference in glucose reading more than 15%. Mean absolute relative difference (MARD) between Libre and serum glucose was 13.2%; mean relative difference (MRD) between Libre and serum glucose was −12.5%.A review of the data pairs showed that 71/467 Accuchek-Libre pairs had one result that was either below 70 mg/dl or above 200 mg/dl (combined American Diabetes Association-ADA-, American College of Physicians-ACP- and American College of Endocrinology-AACE- goals). Thus 85%, of these pairs would have yielded results that engendered the same intervention (e.g. treatment for hypoglycemia or hyperglycemia). Likewise 5/45 Serum-Libre pairs had one result that was either below 70 mg/dl or above 200 mg/dl; thus 89% of these pairs would have yielded results requiring the same intervention. Conclusion/InterpretationThese findings confirm the existent literature and indicate acceptable agreement between the standard POCT and the CGMS as well as between serum glucose and the CGMS values. Because of the advantages of the CGMS over capillary blood glucose testing (reduced patient discomfort and reduced staff exposure to patients in isolation) CGMS use may be preferable to the current bedside capillary blood glucose testing in hospitalized patients with diabetes mellitus. As with other laboratory measures, clinical judgement needs to be exercised when the laboratory values are used to guide patient care.

631-P: Reliability of the Freestyle Libre Continuous Monitoring System in the Inpatient Setting: Implications for the COVID-19 Surge

Introduction: Standard point of care capillary blood glucose testing (POCT) is commonly used in hospitalized patients to monitor their glucose levels. This technique is associated with increased staff/patient contact and patient discomfort. We examined the correlation of the capillary blood glucose results obtained by the POCT device (Accuchek Inform II) with the serum glucose values obtained by the hospital laboratory and with the glucose readings obtained by the FDA-waived for in-patient use (because of COVID-19 pandemic) Freestyle Libre continuous glucose monitoring system (CGMS). Methods: For this prospective cohort study fifty-two adult participants who were diagnosed with diabetes mellitus and admitted to non-critical units were recruited. Among them, 41 (79%) were male, 50 (96%) had type 2 diabetes mellitus. CGMS sensors were placed on patients’ arms, POCT and serum glucose measurements were taken as ordered. Descriptive statistics were calculated and linear mixed models were used to determine correlation. Results: There were a total of 467 Accuchek-Libre pairs with a highly statistically significant association between pairs, p&amp;lt;0.0001. There were also 44 serum glucose -Libre pairs, with a highly statistically significant association, p&amp;lt;0.0001. On average, for each unit increase in Libre glucose level, there was a 0.92 unit increase in Accuchek glucose level as well as a 1.05 unit increase in serum glucose level. Conclusion: These findings indicate excellent correlation between the standard POCT and the CGMS as well as between serum glucose and the CGMS values. Because of the advantages of the CGMS glucose readings over blood capillary glucose testing (reduced patient discomfort and reduced staff exposure to patients during the pandemic) hospitals should consider replacing capillary blood glucose testing with CGMS. Disclosure R. Murray-bachmann: None. K. Ziskovich: None. M. Sarbanes: None. T. Leung: None. A. Myers: None. S. Murthi: None. L. Poretsky: None.

Safety and feasibility of a factory-calibrated continuous glucose monitoring system in term and near-term infants at risk of hypoglycemia.

Hypoglycemia increases the risk of adverse neurological outcomes in neonates. Adequate glucose monitoring requires repetitive and painful blood sampling. We aimed to evaluate the feasibility and accuracy of a continuous glucose monitoring system (CGMS) using factory-calibrated sensors to improve glucose monitoring and decrease the frequency of blood samples in neonates. A methodological study was conducted to investigate a correlation of CGMS values with blood glucose measurements. Factory-calibrated CGMS sensors were placed on 21 infants at risk of hypoglycemia after delivery. CGMS values were compared with blood glucose concentrations. Thirty-seven pairs of CGMS and blood glucose values were obtained. There was a good correlation between CGMS and blood glucose values (R=0.67, p<0.01) with a mean difference (2 standard deviations) of 9.78 (-24.68 to 44.25) mg/dL. The mean differences at <3 hours and ≥3 hours after sensor placement were 17.35 (-4.54 to 39.21) mg/dL and 0.88 (-37.62 to 39.38) mg/dL, respectively. CGMS values were significantly higher than blood glucose concentration at <3 hours after sensor placement (p<0.01), whereas no significant differences in glucose values were observed between the CGMS and blood glucose values at ≥3 hours after sensor placement (p=0.852). The factory-calibrated CGMS was a safe and feasible modality for glucose monitoring. However, it has a tendency to overestimate the blood glucose concentrations. Therefore, this system should be used cautiously for neonates at risk of hypoglycemia, especially within 3 hours after sensor placement.

Continuous subcutaneous glucose monitoring is accurate in term and near-term infants at risk of hypoglycaemia.

Postnatal hypoglycaemia increases the risk of adverse neurological outcomes in newborn infants, and adequate glucose control requires repetitive and painful blood sampling. This study evaluated a continuous glucose monitoring system (CGMS) that aims to improve glucose control and decrease the frequency of blood samples taken from neonates. CGMS sensors, which measure glucose values every five minutes and require calibration twice a day, were placed on 20 infants at risk of hypoglycaemia. The infants also underwent blood glucose sampling, and the blood glucose values were compared with CGMS values six times during the first 30 minutes after sampling. We used 97/264 (37%) of the blood glucose values taken for the CGMS calibration. The highest accuracy, a mean of 0.22 (95% confidence interval 0.13-0.30 mmol/L), was found 15-19 minutes after sampling, due to the calibration process. No significant subcutaneous glucose time lag was detectable. The CGMS system was an accurate and feasible method for glucose control, provided earlier detection of hypoglycaemia in newborn infants and reduced their exposure to procedural pain. The delay in calibration in infants was a new finding and needs to be taken into account when comparing CGMS readings to blood glucose values.

Continuous glucose monitoring system in the operating room and intensive care unit: any difference according to measurement sites?

Given the benefit of glucose control in the perioperative period, we evaluated the accuracy and performance of the continuous glucose monitoring system (CGMS) depending on different measurement sites in the operating room (OR) and in the intensive care unit (ICU). Patients over 18years of age scheduled for elective surgery and ICU admission were enrolled prospectively. Two CGMS sensors were inserted into the subcutaneous tissue of the proximal lateral thigh and the lateral abdomen. The rate of successful measurements from thigh and abdomen in the OR and in the ICU were calculated separately. Each CGMS values were compared with the time-matched arterial blood glucose measurements. CGMS values from both measurement sites were also compared. A total of 22 patients undergoing cardiac surgeries were studied. The rate of successful measurements was higher in the ICU (73.2%) than in the OR (66.0%) (P=0.01); however, that from thigh (72.9%) and from abdomen (58.7%) showed statistically significant difference only in the OR (P=0.04). The Pearson correlation coefficient of thigh and abdomen versus arterial values was 0.67 and 0.60, respectively (P<0.001). In Clarke error grid analysis, 94.6% (89.3% in the OR and 96.1% in the ICU) of values from thigh fell into clinically acceptable zones compared to 93.7% (89.0% in the OR and 95.4% in the ICU) from abdomen. There were no statistically significant differences in the accuracy according to measurement sites. The CGMS showed high measurement failure rate, especially in the OR. In the OR, the rate of successful measurement was higher from thigh than from abdomen. The CGMS showed low accuracy compared to arterial reference values. Nevertheless, there was no difference in the accuracy of the CGMS between two measurement sites. Perioperative performance of the CGMS still needs to be improved considering relatively low successful measurement rates.

Continuous Glucose Monitoring Accuracy Results Vary between Assessment at Home and Assessment at the Clinical Research Center

Continuous glucose monitoring system (CGMS) accuracy is of critical importance both in delivering therapeutic value and as a component of a closed-loop system. This study aims at assessing the differences between accuracy assessments of CGMS at home and at the clinical research center (CRC). Twelve patients with type 1 diabetes used the Dexcom® SEVEN® PLUS (DexCom, Inc.) CGMS for 7 days. Patients performed ≥6 finger pricks [self-measurement of blood glucose (SMBG)] per day while at home. Reference blood glucose measurements were taken during a 24 h CRC admission (YSI 2300 STAT Plus™). Continuous glucose monitoring system data were compared with YSI and SMBG values. Outcome measures included mean absolute relative difference (MARD) and Clarke error grid analysis (CEGA). During CRC admission, the MARD of CGMS vs YSI glucose values was 19.2% (n = 509)--significantly higher than 16.8% at home (n = 611) (p = .004). In the hypoglycemic range, MARD was 23.9% at CRC (n = 26)--not significantly different from 41.6% at home (n = 39) (p = .269). In the hyperglycemic range, CRC MARD at 20.3% (n = 115) was significantly higher than home MARD at 11.2% (n = 118) (p = .001). Clarke error grid analysis showed no significant difference in distribution of data pairs (overall p = .317). This study illustrates the importance of the setting used when assessing CGMS accuracy. Continuous glucose monitoring system accuracy at home appeared better than at the CRC. This is probably due to the higher sampling rate of reference measurements, feasible only in the CRC. Testing CGMS accuracy in the CRC provides valuable information over and above home testing.

Feasibility of Continuous Glucose Monitoring in Critically Ill Emergency Department Patients

BackgroundGlucose control is important in the management of critically ill patients. However, strict glucose control requires a large amount of nursing resources, especially in overcrowded emergency departments (EDs). ObjectivesA continuous glucose monitoring system (CGMS) may be beneficial for glucose control in the ED. The objective of this study was to determine the test characteristics of CGMS in critically ill ED patients. MethodsA prospective observational study of critically ill ED patients was conducted. During a patient’s visit to the ED, a CGMS sensor measured their interstitial fluid glucose levels continuously. Capillary glucose was measured every hour and used for glucose control and as a reference value. CGMS values were recorded in real time and compared with capillary glucose values. ResultsA total of 122 pairs of capillary and CGMS glucose values in 12 patients were analyzed. The correlation coefficient was 0.87, and Bland-Altman analysis showed that 117 pairs (95.9%) were within a 95% confidence interval. A Clarke Error Grid Analysis indicated an overall accuracy of 96.8% (Zones A and B). However, the mean absolute relative difference (MARD) was significantly higher in the hypoglycemic range than in a normo- or hyperglycemic range (p = 0.001). The sensitivity and positive predictive value of CGMS for detecting hypoglycemia were 33.3% and 16.7%, respectively. The CGMS specificity and negative predictive value were 95.8% and 98.3%, respectively. There was no linear correlation between MARD and body mass index, axillary temperature, inotrope score, and base deficit (all p-value >0.05). ConclusionCGMS demonstrated good clinical accuracy by Clarke Error Grid Analysis. There also was high agreement between CGMS and capillary glucose levels. However, CGMS demonstrated only limited real-time hypoglycemia detection ability in critically ill ED patients.

Continuous Glucose Monitoring System in a Rural Intensive Care Unit: A Pilot Study Evaluating Accuracy and Acceptance

Glucose management in an intensive care unit (ICU) is labor-intensive. A continuous glucose monitoring system (CGMS) has the potential to improve efficiency and safety in this setting. The goal of this study was to determine if the Medtronic Guardian REAL-Time CGMS was accurate and tolerated by patients in a rural hospital ICU unit. Differences between individual finger stick blood glucose (FSBG) and CGMS values were compared to American Diabetes Association (ADA) and International Organization for Standardization (ISO) standards. Continuous glucose monitoring system accuracy was evaluated over four ranges: <75, 75-140, 140-200, and >200 mg/dl. Other accuracy measures [mean absolute deviation (MAD), mean absolute relative difference (MARD), and coefficient of linear regression of CGMS on FSBG] were calculated. Nursing staff and patients were surveyed regarding use of the CGMS in the ICU. Twenty-nine participants had 320 FSBG and corresponding CGMS readings. Sixty-two percent of participants were admitted with diabetic ketoacidosis (DKA). Two hundred and thirteen (66.6%) were accurate within the ISO standard, whereas only 70 out of 320 (21.9%) were within the 5% ADA standard. The CGMS was most accurate in euglycemia. Technical difficulties, such as adequate time for "wetting" and calibration of electrodes, arose with the sensors. The MAD was 28.3 mg/dl, the MRAD was 17.4%, and the linear regression coefficient of CGMS on FSBG was 0.834 (p < 0.001). The CGMS is well tolerated by ICU patients but, at present, is not sufficiently accurate to be used for therapeutic decisions in the acute setting, particularly in patients with diabetic ketoacidosis. There is a need to find resolution to the technical issues regarding electrode "wetting" and calibration if CGMS use in the ICU setting is to provide an effective means of diabetes care and management.

Evaluation of a real-time, continuous monitor of glucose concentration in healthy dogs during anesthesia

To evaluate the accuracy of a real-time, continuous glucose monitoring system (CGMS) in healthy dogs undergoing anesthesia for elective ovariohysterectomy or orchiectomy. 10 healthy dogs undergoing routine elective surgery. A CGMS was placed and used to obtain calculated glucose measurements before, during, and after anesthesia in each dog. Periodically, CGMS measurements were compared with concurrent measurements of glucose concentration in peripheral venous blood obtained with a portable chemistry analyzer (PCA). CGMS-calculated glucose measurements were significantly different from PCA blood glucose measurements during most of the anesthetic period. The CGMS values differed from PCA values by > 20% in 54 of 126 (42.9%) paired measurements obtained during the anesthetic period. Hypoglycemia was evident in CGMS measurements 25 of 126 (19.8%) times during anesthesia. By comparison, only 1 incident of hypoglycemia was detected with the PCA during the same period. Use of the CGMS for routine monitoring of interstitial glucose concentration as an indicator of blood glucose concentration during anesthesia cannot be recommended. Additional investigation is necessary to elucidate the cause of discrepancy between CGMS results and PCA data during anesthesia.

Monitorización continua de glucosa para cribado de alteraciones hidrocarbonadas en fibrosis quística

Background Diabetes mellitus (DM) is an increasing complication of cystic fibrosis (CF). It is associated with enhance morbidity. Continuous glucose monitoring system (CGMS) could detect glucose disorders earlier than other screening tests usually used. Aims To compare oral glucose tolerance test (OGTT), HbA 1c and CGMS in patients with CF and recent disorders of glucose homeostasis and to analyse changes in nutritional status and/or pulmonary function. Patients and methods Thirteen patients with CF (11–22 years, 7 males) were studied using OGTT, HbA 1c and CGMS. All of them had newly diagnosed glucose disturbances. They were not receiving steroid therapy or had an underlying illness. In all subjects we compared: HbA 1c levels (%), fasting and 2-hours glucose OGTT (mg/dl) and glucose CGMS values (overall, fasting, 2-hours post mean-meals and excursions >140 mg/dl at any time). Furthermore, body mass index, forced expiratory volume in the first second (%) and forced vital capacity (%) were evaluated in the previous year and at the time of the study. We also analysed exocrine pancreatic function and CF-mutation. Results Mean age at diagnosis of glucose disturbance was 16.4 years. All patients had insufficient exocrine pancreatic function and 11/13 presented ΔF508 CF-mutation. Only one patient was diagnosed with DM using OGGT and 7/13 (53.8%) with CGMS. A total 77% of patients had poor nutritional status and/or pulmonary function at time of diagnosing the glucose disorder. Only 4 patients had abnormal HbA 1c levels. Conclusions CGMS allows a better detection of glucose disorders than OGTT. Glucose homeostasis abnormalities are associated with a decrease in nutritional status and/or pulmonary function. HbA 1c does not aid in the early diagnose of glucose disorders.

Effect of carbohydrate treatment on mild symptomatic hypoglycaemia, assessed by continuous glucose monitoring

AbstractBackground: Appropriate self-treatment of mild symptomatic hypoglycaemia is essential to prevent severe hypoglycaemia. Danish national guidelines recommend 10–20 g of refined carbohydrate (CH) initially, followed by a non-specified amount of unrefined CH.Aim: Our aim was to explore the effect of the amount of CH taken on glucose concentrations recorded by the MiniMed Continuous Glucose Monitoring System (CGMS) at mild symptomatic hypoglycaemic episodes.Method: A total of 125 adult patients with type 1 diabetes underwent 6 days of CGMS. HemoCue blood glucose determinations were used for calibration. All mild symptomatic episodes with a concomitant CGMS value ≤3.5 mmol/l were included in the analysis. Participants completed a detailed diary documenting all meals and snacks, insulin doses, and episodes and self-treatment of hypoglycaemia. CGMS values recorded 30 and 60 minutes after the episode were compared to CH intake. An initial intake of <10 g CH was defined as under treatment, and an intake of ...

Performance of the continuous glucose monitoring system (CGMS) during development of ketosis in patients on insulin pump therapy

Ketoacidosis is one of the most severe complications of Type 1 diabetes. Development of ketosis leads to substantial shifts in electrolyte and ion concentrations in the different fluid compartments of the body. This study was performed to investigate the performance of the continuous glucose monitoring device (CGMS) during ketoacidosis. Twelve patients with Type 1 diabetes using continuous subcutaneous insulin infusion (CSII) participated in this trial [10 women, two men; age (mean +/- sd) 34 +/- 9 years; disease duration 17 +/- 10 years; HbA(1c) 7.1 +/- 1.0%]. In the morning, patients ate breakfast and the insulin pump was stopped at 11.00 h and restarted after 8 h. Observation parameters during this experiment were: blood glucose (laboratory reference and CGMS), 3-hydroxy-butyrate (3-OHB), pH, Na, pCO(2), pO(2), free fatty acids, osmolarity, standard bicarbonate, and lactate. Blood glucose increased and reached a plateau within 2 h after pump stop (from 6.2 +/- 2.56 to 16.7 +/- 4.44 mmol/l, P < 0.001). A constant increase in 3-OHB (from 0.0 to 0.8 +/- 0.5 mmol/l, P < 0.001) and decrease in pH (from 7.43 +/- 0.02 to 7.40 +/- 0.03, P < 0.05) indicated ketosis development. Na decreased from 141 +/- 1.4 to 138 +/- 2.8 mmol/l, P < 0.001). Free fatty acids increased from 0.577 +/- 0.330 to 1.330 +/- 0.462 mmol/l (P < 0.001). The CGMS values showed excellent agreement with the capillary blood laboratory method during the entire experiment, and a modified error grid analysis revealed that 99.5% of the values were in the clinically acceptable zones A and B. The CGMS device was confirmed to be reliable and accurate during the development of hyperglycaemia and ketotic conditions.

Monitoring Exercise-Induced Changes in Glycemic Control in Type 2 Diabetes

The present study determined the efficacy of the Continuous Glucose Monitoring System (CGMS) during moderate exercise and monitored the changes in whole-day glucose profiles using the CGMS in individuals with and without type 2 diabetes. Six, obese, diet-treated individuals with and four age-matched individuals without type 2 diabetes were monitored using the CGMS for 3 d. Subjects cycled at 90% of a predetermined lactate threshold for 1 h at approximately 09:00 h on day 2, during which venous blood was sampled at 10-min intervals and immediately analyzed for glucose concentrations. Venous blood glucose and CGMS values declined during exercise in the diabetes (P < 0.001) but not the control group (P = 0.085). The CGMS overestimated blood glucose in the control (P = 0.003) and the diabetes (P = 0.045) groups during exercise. The number of data points outside of the 95% confidence intervals was <5% in both groups, showing that there is a statistically acceptable level of agreement between venous blood glucose and CGMS values during exercise. Moderate exercise improved whole-day average glucose concentrations (P = 0.007) and whole-day area under the glucose curve (P = 0.016) values (AUCglu), and the time spent within +/-10% of fasting venous glucose (FVG) increased in the diabetes group (P = 0.021). No such effects were seen in the control group. Using continuous glucose monitoring we were able to demonstrate that a period of moderate exercise improved whole-day glycemic control in obese individuals with type 2 diabetes. The CGMS should only be used as an adjunct and not as an alternative to frequent blood glucose sampling when examining the changes in glucose values during exercise in individuals with and without type 2 diabetes.

Evaluation of a continuous glucose monitoring system in cats with diabetes mellitus

A continuous glucose monitoring system (CGMS) was evaluated in 14 cats with naturally occurring diabetes mellitus. The device measures interstitial fluid glucose continuously, by means of a sensor placed in the subcutaneous tissue. All cats tolerated the device well and a trace was obtained on 15/16 occasions. There was good correlation between the CGMS values and blood glucose concentration measured using a glucometer (r=0.932, P<0.01). Limitations to the use of the CGMS are its working glucose range of 2.2-22.2 mmol/l (40-400 mg/dl) and the need for calibration with a blood glucose measurement at least every 12 h. When compared to a traditional blood glucose curve, the CGMS is minimally invasive, reduces the number of venepunctures necessary to assess the kinetics of insulin therapy in a patient and provides a truly continuous glucose curve.

Use of the Continuous Glucose Monitoring System to Guide Therapy in Patients With Insulin-Treated Diabetes: A Randomized Controlled Trial

To show improved glycemic control in patients with insulin-treated diabetes after adjustments to the diabetes management plan based on either continuous glucose monitoring using the Continuous Glucose Monitoring System (CGMS) or frequent self-monitoring of blood glucose (SMBG) using a home blood glucose meter. From January to September 2000, patients aged 19 to 76 years with insulin-treated diabetes were assigned to insulin therapy adjustments based on either CGMS or SMBG values. At the end of the study, patients in both groups used the CGMS for 3 days; these values were used to calculate measures of hypoglycemia. Repeated-measures analysis of variance with post hoc comparisons were used to test differences in hemoglobin A1c levels and hypoglycemia between the 2 study groups. A total of 128 patients were enrolled in the study. Nineteen discontinued study participation, leaving 51 in the CGMS group and 58 in the SMBG group. No significant differences were noted in demographics or baseline characteristics between the 2 groups. There were no significant differences in hemoglobin A1c levels between the CGMS group and the SMBG group at baseline (9.1% +/- 1.1% vs 9.0% +/- 1.0%, P = .70), and both groups showed statistically significant (P < .001) and similar (P = .95) improvement in hemoglobin A1c levels after 12 weeks of study. However, the CGMS group had a significantly shorter duration of hypoglycemia (sensor glucose, < or = 60 mg/dL) at week 12 of the study (49.4 +/- 40.8 vs 81.0 +/- 61.1 minutes per event, P = .009). Use of the CGMS to guide therapy adjustments in patients with insulin-treated diabetes reduces the duration of hypoglycemia compared with therapy adjustments guided by SMBG values alone.

Continuous Glucose Monitoring and the Reality of Metabolic Control in Preschool Children With Type 1 Diabetes

To determine using the MiniMed continuous glucose monitoring system (CGMS) 1) whether twice-daily insulin injection therapy achieves adequate control in preschool children with type 1 diabetes and 2) whether the CGMS is more informative than self-monitoring of blood glucose (SMBG) regarding glucose control and well tolerated by preschool children and their families. Ten children <6 years of age with type 1 diabetes were monitored twice using the CGMS. The distribution of glucose values was analyzed, particularly the frequency, duration, and distribution of hypoglycemia. We analyzed the accuracy of the CGMS in detecting hypoglycemia as well as the clinical relevance of the difference between CGMS and SMBG values. Although hypoglycemia was more frequent during the night (0.8 nighttime episodes . subject(-1) . 24 h(-1) vs. 0.3 daytime episodes . subject(-1) . 24 h(-1)), the difference did not reach statistical significance (P=0.07). However, nighttime episodes lasted longer than daytime episodes (1.2 vs. 0.2 h . subject(-1) . 24 h(-1), P=0.006). Hypoglycemia accounted for 7% and normoglycemia for 24%, while hyperglycemia occurred 64% of the time, with postprandial hyperglycemia being an almost universal feature (94 +/- 7% of all postmeal values). The CGMS correlated well with SMBG without significant clinical discrepancy. The CGMS sensitivity to detect hypoglycemia was 70% with a specificity of 99%; however, the CGMS detected twice as many total episodes as SMBG (82 vs. 40). Twice-daily insulin injection rarely achieves control in preschool children with type 1 diabetes. The CGMS is well tolerated by patients and has the advantage of revealing daily glucose trends missed by SMBG.

The glycemic excursions in normal glucose tolerance individuals revealed by continuous glucose monitoring system

To probe more details about the daily glycemic excursions in normal glucose tolerance (NGT) individuals. The fluctuations of glucose levels in 43 NGT individuals were measured by continuous glucose monitoring system (CGMS) for (72 +/- 7) hours. The number of glucose values detected by CGMS amounted to 858 +/- 77 with a mean absolute difference (MAD) of 8.9% +/- 3.0%. The CGMS values in this study were significantly correlated with the plasma glucose and capillary glucose measurements (n = 204, r = 0.93; n = 804, r = 0.95; both P < 0.001). The glycemic excursions revealed that the daily glycemic levels were lower at night and before meals, the climax of daily glycemic level tended to appear 1- 2 hours after meals, particularly after dinner. The average glycemic value was 5.3 mmol/L. The daily glycemic peak and nadir levels were (7.8 +/- 1.4) mmol/L and (3.9 +/- 0.7) mmol/L respectively; the difference between maximal and minimal glucose levels was (3.9 +/- 1.6) mmol/L. Twenty-seven of the 43 individuals (63%) showed glycemic excursion above 7.8 mmol/L, and 9 individuals (21%) showed brief glycemic excursion below 2.8 mmol/L. During 95% (74% - 100%) of the daytime the glycemic level drifted to and fro between 3.3 mmol/L and 7.0 mmol/L; and during 99% (87% - 100%) of the daytime the glycemic level drifted to and fro between 2.8 mmol/L and 7.8 mmol/L. The profile of glycemic excursion in NGT individuals may have an important significance in defining the diagnostic cut-points and targets for glycemic control on diabetes mellitus.

Conventional measures underestimate glycaemia in cystic fibrosis patients.

Diabetes mellitus is an increasingly important complication of cystic fibrosis (CF). The association with increased morbidity of cystic fibrosis-related diabetes (CFRD) has emphasized the need for accurate monitoring of glycaemia in all CF patients. The diagnosis has relied on conventional thresholds in an oral glucose tolerance test (OGTT) derived from epidemiological studies in non-CF subjects. However, it has not been established if these values are equivalent in CF and non-CF populations. We compared glycaemia in 21 non-diabetic CF subjects with 21-age and BMI-matched non-CF controls using HbA(1c), OGTT and a subcutaneous continuous glucose monitoring system (CGMS) that measures interstitial glucose levels. All conventional measures of glycaemia were similar in the two groups: HbA(1c) mean CF vs. controls (5.5 vs. 5.3%P = 0.4), fasting glucose (4.8 vs. 4.7 mmol/l P = 0.7) and 2-h glucose (5.8 vs. 5.7 mmol/l P = 0.8). However, these conventional measures did not accurately reflect glycaemia 30-, 60- and 90-min. Glucose values and area under the curve in OGTT were all higher in CF subjects than controls (P = 0.01-0.0001). Mean CGMS value [5.9 (0.8) vs. 5.1 (0.5) mmol/l, P = 0.004], and the proportion of subjects with peak CGMS values > 11.1 mmol/l (33 vs. 5%P = 0.00001) were also higher in CF subjects than controls. These results remained significantly different when only subjects with normal glucose tolerance in the two groups were studied. We have shown that overall glycaemia, as shown by both the response during an OGTT and CGMS, is higher in CF subjects who have similar HbA(1c), fasting and 2-h glucose values. These results question whether it is appropriate to use the diagnostic thresholds and OGTT time points derived from the non-CF population for a diagnosis of diabetes in patients with cystic fibrosis.