Administered indexing terms (eg, MeSH in PubMed and Emtree in Embase) and free-text search terms included (a) muscle mass and strength, (b) cognitive decline and dementia, and (c) predetermined pathophysiological mechanisms: “insulin resistance,” “mitochondrial function,” “protein metabolism,” and “inflammation” (Supplementary Appendix). This evidence concerns the gene INS and Mental deterioration.