title: Continuous glucose monitoring system in free-living healthy subjects: results from a pilot study.
abstract: OBJECTIVE
  The Continuous Glucose Monitoring System (CGMS) (Medtronic Minimed, Northridge, CA) provides an opportunity to better understand abnormalities in glucose metabolism in both healthy subjects and those with diabetes. The aims of our study were to assess the reliability of CGMS compared to self-monitoring of blood glucose (BG) and to analyze the graphs obtained in a sample of healthy free-living subjects in order to establish the suitability of CGMS in physiological studies.
  
  
  METHODS
  Eighteen healthy adults, 12 women and six men, were enrolled in this study. Each subject performed 24-h CGMS and inserted 24 glycemic values, measured through a glucose meter, during their common daily activities. Three subjects were excluded from the analysis since they did not meet accuracy criteria. None of the participants received any advice as regard diet and physical activity. Means and standard deviations were used to summarize quantitative data. Normal distribution of data was tested with the Shapiro-Wilk W test. Differences over time and association between glucose levels with other variables were evaluated with linear regression models for repeated measures.
  
  
  RESULTS
  We did not find statistically significant differences between CGMS measures and meter readings. In the subjects studied the mean glucose levels increase according to age, and we found a mean increase in glucose concentration of 0.50 mg/dL for every year of age. As regards gender, men presented a 4.63% higher mean glucose concentration than women. A 1.16% higher glucose concentration for every unit (kg/m(2)) of body mass index (BMI) was observed in both groups. All subjects presented glucose concentrations within the established range of normal glucose levels for 91% of the total duration of CGMS.
  
  
  CONCLUSIONS
  Our results suggest that long-term studies on larger groups of healthy subjects performing CGMS would be useful in order to better understand if BMI, daily stressors due to work or psychological stress, or other factors can influence daily BG variability and if these nonpathological alterations are related to development of glucose metabolism disorders.
authors.affiliation: Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy. derosa@unipv.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Derosa
authors.forename: Sibilla A T
authors.initials: SA
authors.lastname: Salvadeo
authors.forename: Roberto
authors.initials: R
authors.lastname: Mereu
authors.forename: Angela
authors.initials: A
authors.lastname: D'Angelo
authors.forename: Leonardina
authors.initials: L
authors.lastname: Ciccarelli
authors.forename: Mario N
authors.initials: MN
authors.lastname: Piccinni
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ferrari
authors.forename: Alessia
authors.initials: A
authors.lastname: Gravina
authors.forename: Pamela
authors.initials: P
authors.lastname: Maffioli
authors.forename: Carmine
authors.initials: C
authors.lastname: Tinelli
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000379:methods; D004435:Eating; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods*; D010865:Pilot Projects; D012016:Reference Values; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D001786:Blood Glucose