title: Effect of alterations in blood volume with bed rest on glucose tolerance.
abstract: Bed rest leads to rapid impairments in glucose tolerance. Plasma volume and thus dilution space for glucose are also reduced with bed rest, but the potential influence on glucose tolerance has not been investigated. Accordingly, the aim was to investigate whether bed rest-induced impairments in glucose tolerance are related to a concomitant reduction in plasma volume. This hypothesis was tested mechanistically by restoring plasma volume with albumin infusion after bed rest and parallel determination of glucose tolerance. Fifteen healthy volunteers (age 24 ± 3 yr, body mass index 23 ± 2 kg/m2, maximal oxygen uptake 44 ± 8 ml·min-1·kg-1; means ± SD) completed 4 days of strict bed rest. Glucose tolerance [oral glucose tolerance test (OGTT)] and plasma and blood volumes (carbon monoxide rebreathing) were assessed before and after 3 days of bed rest. On the fourth day of bed rest, plasma volume was restored by means of an albumin infusion prior to an OGTT. Plasma volume was reduced by 9.9 ± 3.0% on bed rest day 3 and area under the curve for OGTT was augmented by 55 ± 67%. However, no association (R2= 0.09, P = 0.33) between these simultaneously occurring responses was found. While normalization of plasma volume by matched albumin administration (408 ± 104 ml) transiently decreased (P < 0.05) resting plasma glucose concentration (5.0 ± 0.4 to 4.8 ± 0.3 mmol/l), this did not restore glucose tolerance. Bed rest-induced alterations in dilution space may influence resting glucose values but do not affect area under the curve for OGTT.
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: S
authors.initials: S
authors.lastname: Dandanell
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: L
authors.initials: L
authors.lastname: Oberholzer
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: S
authors.initials: S
authors.lastname: Keiser
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: A B
authors.initials: AB
authors.lastname: Andersen
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: T
authors.initials: T
authors.lastname: Haider
authors.affiliation: Intensive Care Unit, University Hospital of Zürich, Zurich, Switzerland.
authors.forename: M P
authors.identifier: 0000-0002-2765-881X
authors.initials: MP
authors.lastname: Hilty
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and.
authors.forename: A K
authors.initials: AK
authors.lastname: Meinild-Lundby
authors.affiliation: Institute of Physiology, University of Zürich, Zurich, Switzerland; and carsten.lundby@access.uzh.ch.
authors.forename: C
authors.initials: C
authors.lastname: Lundby
mesh_terms: D000328:Adult; D000418:Albumins / Q000008:administration & dosage; D001510:Bed Rest / Q000379:methods; D001786:Blood Glucose / Q000378:metabolism*; D001810:Blood Volume / Q000502:physiology*; D015992:Body Mass Index; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000379:methods; D006801:Humans; D008297:Male; D010953:Plasma Volume / Q000502:physiology*; D055815:Young Adult
chemical_list: D000418:Albumins; D001786:Blood Glucose; D005947:Glucose
keywords: dilution space; impaired glucose tolerance; insulin resistance; oral glucose tolerance test; plasma volume