Table 3.
Summary of the characteristics of the PRS samples for the four bone regions
| Femoral head (n = 305,313) | Total hip (n = 305,453) | Diaphysis (n = 306,222) | Spine (n = 303,066) | |
|---|---|---|---|---|
| Age at assessment center (years)* | 57.04 (8.02) | 57.03 (8.02) | 57.04 (8.02) | 57.06 (8.02) |
| Sex | ||||
| Male | 141,114 (46.22%) | 141,542 (46.34%) | 142,030 (46.38%) | 139,343 (45.98%) |
| Female | 164,199 (53.78%) | 163,911 (53.66%) | 164,192 (53.62%) | 163,723 (54.02%) |
| Polygenic risk score | ||||
| PRS1 | 0.09 (0.34) | −0.16 (0.64) | −1.77 (0.75) | −0.53 (0.72) |
| PRS2 | 0.14 (0.31) | −0.11 (0.63) | NA | −0.47 (0.72) |
The polygenic risk score (PRS) for each bone region was constructed by adding up the number of BMFF-increasing alleles for each SNP, weighted for the SNP effect size on BMFF level (beta coefficients from meta-GWAS); a higher PRS value suggests a greater genetic predisposition to BMFF variation. The quality control of the SNPs and samples used to generate PRS for each bone region is summarized in Supplementary Data 11–13. The number of SNPs for PRS1 and PRS2 for each site are as follows: PRS1 – femoral head = 48, total hip = 115, diaphysis = 99, spine = 119; PRS2 – femoral head = 46, total hip = 114, spine = 117. For diaphysis, PRS2 was not generated because no SNPs in PRS1 (diaphysis) were independently associated with BMD. *Values are presented as mean (sd). Numbers of participants in each sex and ancestry category are shown as absolute number, with % of total for each bone region indicated in parentheses.