title: The cerebral vascular response to a rapid decrease in blood glucose to values above normal in poorly controlled type 1 (insulin-dependent) diabetes mellitus.
abstract: The effect of rapid lowering of blood glucose on cerebral blood flow (CBF) was studied in 10 Type 1 (insulin-dependent) diabetic patients (age 23.5 +/- 3.8 years; mean +/- S.D.) with longstanding, poor metabolic control (HbAlc 11.2 +/- 1.0%; normal value 4.0-5.3%) using an intravenous xenon 133 single photon emission computed tomography technique. After a fall in blood glucose, during 81 +/- 11 min (mean +/- S.E.M.), from 18.2 +/- 1.4 mmol/l to 9.2 +/- 0.9 mmol/l CBF was unchanged, but increased from its initial value of 48.8 +/- 2.9 ml/100 g per min to 57.1 +/- 2.4 ml/100 g per min (P < 0.001) when the blood glucose level was restored. The CBF was higher in the right compared to the left hemisphere at all measurements (1.8 +/- 0.5 ml/100 g per min, P < 0.01; 1.9 +/- 0.5 ml/100 g per min, P < 0.05; 2.1 +/- 0.7 ml/100 g per min, P < 0.05, respectively). The change in CBF was inversely correlated with time for fall of blood glucose, but there was no correlation with absolute levels of blood glucose. The respiratory end-tidal PCO2 decreased during the low blood glucose level, but there was no correlation between the PCO2 and CBF. The cerebral volume was unchanged during the study. The results indicate that in patients with chronic hyperglycemia a rapid fall in blood glucose may cause a rise in CBF of the same magnitude as previously shown during absolute hypoglycemia in patients with well controlled diabetes mellitus and in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Internal Medicine, University Hospital, Lund, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Eckert
authors.forename: E
authors.initials: E
authors.lastname: Ryding
authors.forename: C D
authors.initials: CD
authors.lastname: Agardh
mesh_terms: D000328:Adult; D017668:Age of Onset; D000419:Albuminuria; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply; D002245:Carbon Dioxide / Q000032:analysis; D002560:Cerebrovascular Circulation; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology*; D008297:Male; D010313:Partial Pressure; D012016:Reference Values; D012039:Regional Blood Flow; D015899:Tomography, Emission-Computed, Single-Photon; D014655:Vascular Resistance; D014980:Xenon Radioisotopes
chemical_list: D001786:Blood Glucose; D002245:Carbon Dioxide; D006442:Glycated Hemoglobin; D014980:Xenon Radioisotopes