A common polymorphism in the UCP3 promoter influences hand grip strength in elderly people.

The reduction of muscle mass in the elderly is widely studied as one of the most important landmark of human aging. This process, which occurs for the decay of the correct energetic and protein metabolism, has important functional consequences on individual functionality but also on metabolic adaptation and immunological response to environmental challenges. Uncoupling Protein 3 (UCP3) gene is expressed in skeletal muscle where it regulates fatty acid metabolism, redox state, and ROS formation. Considering the importance of these processes in aging, we studied two variants of the UCP3 gene in a large, aged (age range 65-105) population of southern Italy verifying if these variants were correlated to hand grip strength, the most reliable measure of muscle decay. We found that a previously described functional polymorphism, rs1800849, located in the promoter region of the UCP3 gene, has a significant impact on hand grip strength. In fact, the carriers of rs1800849 T allele showed higher hand grip than the remaining of the population. Since this allele has been reported to promote a higher expression of the gene, we conclude that a more efficient uncoupling process has a beneficial effect on the aging muscle by slowing down its age related decay.