The plasma volume expansion curves were of interest. Our hypothesis was that there should be a lag time in absorption when the fluid was given orally compared to intravenously. We anticipated that this lag time could be estimated with a volume kinetic model. Furthermore, we also anticipated that older subjects would have a slower elimination of both the glucose and the fluid given. Methods The study was designed as a prospective crossover study and was approved by the Ethical Review Board in the Stockholm County (Dno 2008/385-31/3). It was funded by the Stockholm County (PickUpFunding). The experiments were performed at the Geriatric Department,