title: Continuous monitoring of the subcutaneous glucose level in freely moving normal and diabetic rats and in humans with type 1 diabetes.
abstract: Laboratory animals are extensively used in diabetic research. However, it is not known whether the glucose dynamics in laboratory animals are similar to the dynamics in humans. The aim of the present study is to see whether the Medtronic MiniMed continuous subcutaneous glucose monitoring system can be used to record fluctuations of the glucose level in freely moving normal and insulin-treated diabetic rats. The monitoring system was applied during 3 days to normal and diabetic hyperglycemic and hypoglycemic rats treated with insulin implants. Corresponding data from type 1 diabetic patients with poor glycemic control were selected retrospectively in order to note the similarities and differences. In normal rats the subcutaneous glucose level varied slightly (median = 111 mg/dL). In hyperglycemic rats the subcutaneous glucose values fluctuated markedly around a median of 226 mg/dL. The fluctuations formed a short-wave pattern with a low amplitude, superimposed on a long-wave pattern with a high amplitude. The subcutaneous glucose profile seen in type 1 diabetic patients (median = 180 mg/dL) was similar to that observed in hyperglycemic rats. In hypoglycemic rats, the subcutaneous glucose level fluctuated moderately around a median of 55 mg/dL. In these rats the fluctuations formed a short-wave pattern with low amplitude, without any obvious long-wave pattern. The subcutaneous glucose values conformed to corresponding blood glucose measurements. We conclude that the Medtronic MiniMed continuous glucose monitoring system can be used to record the subcutaneous glucose level over time in freely moving rats.
authors.affiliation: Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Reza
authors.initials: R
authors.lastname: Jamali
authors.forename: Johnny
authors.initials: J
authors.lastname: Ludvigsson
authors.forename: Simin
authors.initials: S
authors.lastname: Mohseni
mesh_terms: D000293:Adolescent; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring; D002138:Calibration; D002648:Child; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000188:drug therapy; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007003:Hypoglycemia / Q000097:blood; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008904:Miniaturization; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000098:blood supply; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin