Article Figures & Data
Figures
- Figure 1.
A, square root dense area by age at time 1 and time 2. Random sample of N = 100 subjects. B, square root percentage dense area by age at time 1 and time 2. Random sample of N = 100 subjects.
- Figure 2.
A, age- and BMI-adjusted square root dense area at time 1 versus time 2. B, age- and BMI-adjusted square-root percentage dense area at time 1 versus time 2.
Tables
- Table 1.
Mean and SD of characteristics of subjects by zygosity
Characteristic Monozygotic pairs (N = 204) Mean (SD) Dizygotic pairs (N = 123) Mean (SD) Age at mammogram time 1, y 49.75 (7.71) 50.76 (8.61) Age at mammogram time 2, y 57.61 (7.87) 58.83 (8.60) Difference in age between times 1 and 2, y 7.87 (1.57) 8.06 (1.45) BMI at time 1, kg/m2 24.75 (4.17) 25.12 (4.44) BMI at time 2, kg/m2 25.65 (4.33) 25.95 (4.58) Dense area at time 1, cm2 30.77 (21.65) 32.73 (23.70) Dense area at time 2, cm2 25.87 (20.01) 28.76 (23.16) Percent dense area at time 1 29.92 (17.96) 30.37 (18.60) Percent dense area at time 2 22.64 (15.78) 23.41 (15.91) - Table 2.
Estimates and SEs of the cross-time correlation between 2 mammograms within the same individual and of the cross-time cross-twin correlation between time 1 mammogram in one twin and time 2 mammogram in the other twin
Dense areaa Percent dense areaa Estimate (SE) P Estimate (SE) P Correlation within same individual 0.86 (0.01) <0.001 0.82 (0.01) <0.001 Monozygotic cross-correlation 0.71 (0.03) <0.001 0.65 (0.03) <0.001 Dizygotic cross-correlation 0.25 (0.07) <0.001 0.20 (0.08) 0.01 -
↵aResiduals after square root transformation and adjustment for age and BMI.
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- Table 3.
Regression estimates and SEs of association between mammographic measures at time 2 and mammographic measures at time 1 adjusting for co-twin and/or zygosity; N = 654
Dense areaa Percent dense areaa Estimate (SE) P Estimate (SE) P Model I Self 0.86 (0.021) <0.001 0.77 (0.022) <0.001 Co-twin Model IIa Self Co-twin 0.78 (0.024) <0.001 0.66 (0.027) <0.001 Model IIb Self Co-twin MZ 0.84 (0.031) <0.001 0.73 (0.035) <0.001 DZ 0.63 (0.042) <0.001 0.42 (0.046) <0.001 Model IIIa Self 0.83 (0.020) <0.001 0.75 (0.023) <0.001 Co-twin 0.063 (0.022) 0.004 0.066 (0.023) 0.004 Model IIIb Self 0.82 (0.020) <0.001 0.74 (0.025) <0.001 Co-twin MZ 0.090 (0.031) 0.004 0.100 (0.032) 0.002 DZ 0.035 (0.031) 0.3 0.029 (0.033) 0.4 -
↵aResiduals after square root transformation and adjustment for age and BMI.
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Volume 21, Issue 7
