Table 2.
DNA Methylation at LINE-1, H19, HSD11B2 and IGF2 among all individuals and stratified by sexa.
| Entire Cohort |
Boys |
Girls |
|||||
|---|---|---|---|---|---|---|---|
| N | Mean % methylation (SD) | N | Mean % methylation (SD) | N | Mean % methylation (SD) | P valueb | |
| LINE-1 methylation | |||||||
| Site 1 | 243 | 79.88 (3.87) | 113 | 80.48 (4.13) | 130 | 79.37 (3.57) | 0.026 |
| Site 2 | 243 | 81.89 (1.99) | 113 | 82.20 (2.15) | 130 | 81.62 (1.80) | 0.022 |
| Site 3 | 243 | 78.64 (2.93) | 113 | 79.26 (2.99) | 130 | 78.10 (2.77) | 0.002 |
| Site 4 | 243 | 73.54 (2.14) | 113 | 73.96 (1.96) | 130 | 73.18 (2.22) | 0.004 |
| H19 methylation | |||||||
| Site 1 | 245 | 59.08 (8.24) | 115 | 58.46 (7.57) | 130 | 59.63 (8.79) | 0.266 |
| Site 2 | 245 | 58.23 (4.83) | 115 | 58.23 (3.32) | 130 | 58.22 (5.87) | 0.990 |
| Site 3 | 245 | 59.26 (3.78) | 115 | 59.05 (3.54) | 130 | 59.45 (3.98) | 0.412 |
| Site 4 | 245 | 56.66 (8.51) | 115 | 55.83 (7.74) | 130 | 57.39 (9.09) | 0.153 |
| HSD11B2 methylation | |||||||
| Site 1 | 246 | −1.54 (2.14) | 115 | −1.57 (2.35) | 131 | −1.51 (1.94) | 0.844 |
| Site 2 | 246 | 0.08 (0.92) | 115 | −0.04 (0.92) | 131 | 0.19 (0.92) | 0.057 |
| Site 3 | 245 | −2.20 (2.25) | 115 | −2.23 (2.33) | 130 | −2.18 (2.19) | 0.856 |
| Site 4 | 244 | −0.76 (1.75) | 115 | −0.70 (1.58) | 129 | −0.81 (1.89) | 0.601 |
| Site 5 | 229 | 0.24 (4.46) | 108 | 0.20 (4.33) | 121 | 0.28 (4.58) | 0.898 |
| IGF2 methylation | |||||||
| Site 1 | 223 | 35.15 (12.23) | 101 | 34.71 (11.98) | 122 | 35.51 (12.46) | 0.630 |
| Site 2 | 213 | 44.85 (14.06) | 94 | 42.99 (14.56) | 119 | 46.31 (13.54) | 0.087 |
| Site 3 | 228 | 53.79 (6.40) | 102 | 53.57 (6.92) | 126 | 53.97 (5.97) | 0.644 |
| Site 4 | 196 | 37.87 (4.26) | 88 | 37.69 (4.65) | 108 | 38.01 (3.94) | 0.607 |
| Site 5 | 229 | 52.94 (6.51) | 103 | 52.90 (6.21) | 126 | 52.97 (6.76) | 0.932 |
a LINE-1, HSD11B2, and H19 data exhibited batch effects and as such were standardized to controls included on experimental plates as previously described [30], while the IGF2 data exhibited no batch effect. Batch adjustment for HSD11B2 involves subtracting the value of the 0% methylated control from each experimental plate and sometimes results in negative values due to low raw methylation values for HSD11B2.
b P-value of 2-sample t test comparing boys and girls.