Increased Blood Flow by Unilateral Intermittent Compression on Hindlimbs May Prevent Bone Loss

Osteoporosis characterized by bone loss increases the risk of bone fracture and seriously affects people’s health. As a non-invasive regimen, intermittent compression (IC) was used in this study to investigate the efficacy on countering bone loss. We aimed to investigate the unilateral effect of intermittent compression on blood flow as well as bone quality in a rat model of disuse with and without IC mechanosignals. 24 rats were randomly divided into three groups ( n = 8, each): hindlimb unloading (HU), HU + intermittent compression (HUIC) and cage-control (CON). The experiment last 21 days. IC was applied on the left hindlimb in HUIC group with a 1 Hz frequency, 30 mmHg pressure for 20 min/day. The blood flow was recorded by a continuous-wave Doppler flowmeter. Bone mineral density (BMD) and structural parameters of trabecular and cortical bone and muscle cross section area was determined using microcomputer tomography (μCT). IC could increase the blood flow and counter bone loss in hindlimbs. Furthermore, it had a cross-over positive effects on the blood flow and bone. The blood flow in uncompressed side was higher than compressed side. There was a significant growth of tibial cortical bone in the uncompressed side versus compressed side in HUIC group. In general, unilateral IC increased the blood flow in both sides and was able to prevent contralateral bone loss induced by hindlimb unloading and the blood flow was involved in this contralateral effect. The cross-over effect of IC on the body provides us a new idea for the treatment of osteoporosis.