MO414: Sucroferric Oxyhydroxide (velphoro®) Treatment Mitigates the Signs of Ageing-Related Sarcopaenia in Old Mice

Abstract BACKGROUND AND AIMS Sarcopaenia, defined as the loss of muscle mass and function, is an ageing-related pathology associated with some important diseases such as chronic kidney disease (CKD). Hyperphosphatemia has been associated with both, ageing and CKD. Old mice show an increase in serum phosphate concentration and a reduction in muscle mass, forelimb strength, gait speed and transition time in the static bar, with respect to young mice. Previous results of our group showed the beneficial effects of a low phosphate diet on ageing-related sarcopaenia. Given that the implementation of dietary phosphate restriction entails difficulties in the elderly, the aim of this work was to analyse the beneficial effects of a diet supplemented with a phosphate binder on the signs of sarcopaenia. METHOD C57BL6 male mice were used for in vivo studies: 5-month-old (young) and 24-month-old (old), which were fed with a powder standard diet (containing 0.6% of phosphate). Some old mice were fed with a hypophosphatemic diet (containing 0.2% of phosphate) or with a diet supplemented with 5% sucroferric oxyhydroxide (Velphoro®) for the last 3 months before sacrifice. Serum phosphate levels were analysed with a commercial kit. Muscle mass was estimated by measuring the gastrocnemius muscle mass divided by total body mass, muscle force was measured by a grip test and physical performance was evaluated by a gait test and the static bar test. RESULTS Velphoro® treated old mice showed a significant and more effective reduction in phosphate serum levels than old mice fed with the hypophosphatemic diet. No differences were observed in the relative gastrocnemius muscle mass between the three old mice experimental groups. By contrast, old mice fed with the standard diet supplemented with Velphoro® displayed an increased muscular strength and physical performance, improving the gait speed and reducing the transition time in the static bar, compared with old mice fed with the standard diet. Results obtained with Velphoro® treatment were similar to those observed in old mice fed with the hyphophosphatemic diet, but Velphoro® treatment achieve better results in motor coordination in the static bar test. CONCLUSION Dietary restriction of phosphate is a useful approach to mitigate the signs of ageing-related sarcopaenia (muscle strength and physical performance) in old mice. The use of Velphoro®, as a phosphate binder, exhibits similar or even better results than the hypophosphatemic diet. Therefore, the administration of Velphoro® could attenuate the signs of sarcopaenia in the elderly or in ageing-related diseases in which sarcopaenia is common, like CKD.