The table lists the most significant age-regulated co-expression modules containing 2, 3, or 5 genes.
The most significant age-related changes were noted in BMD, with a significant decrease in BMD measures in both groups.
In both these female cohorts, the most significant age-related hormonal decreases were noted in DHEA and testosterone levels (Fig. 1).
Genes containing the most significant age-modified CpG sites in peripheral blood leukocytes within 5 years after birth are annotated in the figure (pbonf below 6.5 × 10−8).
Alternatively, we focused only on three CpG sites with the most significant age-associated correlation (NPTX2, GRIA2 and KCNQ1DN) – even this smaller subset facilitated an average precision of ± 10.3 years in the training-set.
The Illumina identifier is presented for three age-methylated CpG sites without any transcripts mapped to their position (intergenic), including the most significant age-modified CpG at chr. 22 28074071 (cg16331674, pbonf = 8.1 × 10−11).
One of the most significant age-gene expression associations we observed in monocytes from 1,264 individuals was with MCL1 (myeloid cell leukemia sequence 1; FDR = 7.6×10−16).
However, the most significant age-related changes in both the active and the inactive groups were noted in BMD, leading to a significant decrease in the measures of BMD in both the groups.
The most significant age-related differentially methylated site in our study was detected on chromosome 6 in the ELOVL2 gene (ELOVL fatty acid elongase 2) which conforms with another recent study [ 39] that focused on only monocyte and T-cell lines as opposed to whole blood (as in this paper).
Because the most significant age-associated module appeared to correlate with lymphocyte cell counts in an independent gene expression dataset, the expression of this module, enriched for ' T-cell activation', was subsequently used as a proxy for possible confounding shifts in the distribution of lymphocyte subsets.
Multivariate analysis of factors associated with sarcopenia was performed by the logistic regression (backward method), which included the six most significant variables: age, cognitive function, admission profile (clinical or surgical), smoking, age ≥80 years and reports of physical inactivity pre-hospitalization (less than 2x per week).
