Efectos del ejercicio vibratorio corporal en hipoxia normobárica sobre la densidad mineral ósea

Résumé

Influence of hypoxia on bone remodelling is unclear and different physiological mechanisms could mediate in its effects. General objectives of this work were: (1) to review the current literature of bone metabolism and hypoxic stimulus; (2) to study the effects of passive hypoxia conditioning on bone mineral density (BMD) of elderly people; and (3) to study the effects of active hypoxia conditioning on healthy parameters of healthy elderly people. A systematic review was carried out following PRISMA. To know the effects of passive hypoxia, elderly adults were exposed to normobaric hypoxic conditions in a hypoxic chamber (16.1% FiO₂). To study the effects of active hipoxia conditioning, experimental groups received the same vibration treatment in a hypoxia chamber under hypoxic or normoxic conditions. Wholebody and proximal femur BMD were measured using DXA. Isokinetic leg muscle strength was evaluated using an isokinetic dynamometer. The "Timed Up and Go Test" evaluated functional mobility. Different modes of hypoxic conditioning may have different impacts on bone metabolism. Passive hypoxia exposure at 16.1% FiO₂ during 36 sessions is apparently enough to significantly increase whole body BMD in older adults. Combined with WBV training, hypoxic stimuli seemed to generate positive effects on whole body and proximal femur BMD. However, active hypoxia does not cause any effect on muscle mass nor strength of older adults. Functional mobility neither changed following an active hypoxia protocol.