title: Evaluation of a Reverse Gradient Garment for prevention of bed-rest deconditioning.
abstract: A Reverse Gradient Garment (RGG) was used to intermittently induce venous pooling in the extremities of a magnitude similar to that seen in going from a lying to standing position during the course of a 15-d period of horizontal bed rest. Venous pooling failed to improve bed-rest-induced losses in +2.5 Gz and +3.0 Gz centrifugation tolerance or to prevent increased heart-rate responses to lower-body negative pressure (LBNP). Four subjects served as controls, four were treated. Tests during the 7-d recovery period showed fluid/electrolyte and body composition values to have returned to pre-bed-rest levels with continued depression of acceleration tolerance times (56% decreased at +2.5 Gz and 74% decreased at +3.0 Gz compared to pre-bed-rest levels) and exaggerated blood insulin response on glucose tolerance testing (blood insulin for treated group increased 95% at 1 h before bed rest and 465% during recovery). This study demonstrates that the physiologic changes after bed rest persist for significant periods of time. Acceleration tolerance time proved to be a sensitive test for the deconditioning process.
mesh_terms: D000054:Acceleration; D000328:Adult; D000337:Aerospace Medicine; D001510:Bed Rest / Q000009:adverse effects*; D001775:Blood Circulation; D001823:Body Composition; D005951:Glucose Tolerance Test; D005676:Gravity Suits; D006801:Humans; D007328:Insulin / Q000097:blood; D008150:Lower Body Negative Pressure; D008297:Male; D005082:Physical Exertion; D013997:Time Factors; D014556:Urine / Q000032:analysis
chemical_list: D007328:Insulin