title: Oral glucose tolerance test reduces arterial baroreflex sensitivity in older adults.
abstract: Although postprandial decreases in blood pressure are a common cause of syncope in the older adult population, the postprandial effects of the oral glucose tolerance test on blood pressure and the arterial baroreflex remain poorly characterized in older adults. Therefore, arterial blood pressure and the arterial baroreflex were studied in 19 healthy older adults (mean age 71.7 +/- 1.1 years) who were given a standardized oral glucose load (75 g) or an isovolumetric sham drink during 2 separate sessions. All measures were taken for 120 min after treatment. Baroreflex function was assessed by using the spontaneous baroreflex method (baroreflex sensitivity, BRS). Subjects demonstrated a decrease in BRS after oral glucose that was not seen in the placebo session (two-way analysis of variance, p = 0.04). There was no significant change in systolic, mean, or diastolic blood pressure; together with a drop in BRS, this resulted in a significant tachycardia post glucose (two-way analysis of variance, p < 0.001). We conclude that healthy older adults can successfully maintain blood pressure during an oral glucose tolerance test despite a decrease in arterial BRS. Decreased BRS resulted in a tachycardic response to glucose.
authors.affiliation: Gordon and Leslie Diamond Health Care Centre, Vancouver, BC V5Z 1M9, Canada. kmmadden@interchange.ubc.ca
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Madden
authors.forename: Gale
authors.initials: G
authors.lastname: Tedder
authors.forename: Chris
authors.initials: C
authors.lastname: Lockhart
authors.forename: Graydon S
authors.initials: GS
authors.lastname: Meneilly
mesh_terms: D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D017704:Baroreflex / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D001795:Blood Pressure Determination; D015992:Body Mass Index; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D005951:Glucose Tolerance Test; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D050177:Overweight
chemical_list: D005947:Glucose