Does Passive Movement Increase Glucose Uptake Into Muscle?

Overview

This study aims to examine the blood sugar response after a meal, and how three different movement protocols may impact the blood sugar level. Participants will visit the lab on three different occasions. Before each visit the participant will eat a meal we give them and have a cannula (a needle with a tube) put in their arm to allow blood sampling for the visit. Visit A will be the participant just having their legs moved by the machine, visit B will be the participant having their legs moved by the machine with the addition of blood pressure cuffs on their thighs, and visit C will just be the participant sitting still on the machine.

This study will require nine participants to be recruited and enrolled. The aim of the study is to determine the effect of passive movement, with and without blood flow restriction, on blood glucose and insulin primarily. Other outcomes included elsewhere in this registration. The protocol will involve an initial health screening/familiarisation session in the Human Performance Laboratory (HPL) at Lancaster University, followed by three randomly ordered HPL visits per participant. At the beginning of each HPL visit, the participant will be given a standard meal. The design is a crossover study therefore each participant will complete visits A, B and C and act as their own control. Each of the visits A, B and C will involve consumption of a meal (86g carbohydrate content) and insertion of a cannula to the arm. Blood samples will then be drawn from the cannula at five minute intervals for approximately 3.5 hours. Three gold-top vacutainers will be taken throughout each visit to allow for insulin analysis. Once the blood is sampled, the vacutainer will be left to clot at room temperature for 15 minutes and then spun in a centrifuge at 4°C, 1800 RCF, for 10 minutes. The supernatant will be transferred to a microfuge tube via pipetting and stored at -80°C until analysis at a future date using an enzyme-linked immunosorbent assay (ELISA). In addition, 1ml syringe blood samples will be taken every 5 minutes and ejected onto a non-absorbent pad. A fraction of this ejection on the pad will then drawn up into a capillary tube to be analysed by a Biosen benchtop glucose/lactate analyser. Visit A will invole the participant sitting on a Biodex isokinetic dynamometer and having both legs passively flexed and extended through 90 degrees, at a frequency of 1Hz for 30 minutes. This will be 60 seconds on, followed by 60 seconds off, repeated 15 times. Visit B will involve the same as visit A, but with the addition of blood flow restriction intermittently. These are blood pressure bands (VALD AirBands) around the thighs which will inflate and deflate to cause 80% arterial occlusion in their inflated state. These will inflate and deflate in tandem with the passive movement going on and off. Visit C is a control visit and will involve the participant sitting in the Biodex only with no movement or blood flow restriction occuring. Throughout the study, measurements will be taken to meausure the outcome measure specified in this registration.