Recent studies have found that aging and frailty affect transcriptome heterogeneity and variability. Based on the existing evidence, this study aims to explore the differences in the transcriptome characteristics of peripheral blood of older people under different frailty states.

The dataset (GSE157007) was downloaded from the Gene Expression Omnibus (GEO) . The distribution and characteristics of cells and the differentially expressed genes between frail and non-frail elderly were analyzed. The differentially expressed genes were performed by Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. The interaction and communication between cells were also studied by CellChat package.

Compared with the non-frail group, the proportion of T cells and monocytes in the frail group was reduced, while the ratio of natural killer cells was increased. No significant difference was found in the cluster of B cells. And there were significant differences in gene expression among cell clusters. KEGG pathway analysis showed that differentially expressed genes were mainly enriched in antigen presentation, Tumor necrosis factor signaling pathway, chemokine signaling pathways. Further analysis of cell communication showed that the number and intensity of interactions between cells of the frail group were less than those in the non-frail group, and frailty states might affect the mode and signaling pathway of interactions between cells.

Significant differences were observed in the transcriptome characteristics of single cells in older people with different frailty states.