Table 2.
Multivariable-adjusted association between body mass index (BMI) and mammographic density (MD)a by race and ethnicity, stratified by age at mammogram
| BMI (kg/m2) | All (n=160,804) |
AIAN (n=631) |
Asian (n=1,828) |
Black (n=821) |
Hispanic (n=8,791) |
NHPI (n=271) |
White (n=148,462) |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low MD (n) |
High MD (n) |
RR (95% CI) |
Low MD (n) |
High MD (n) |
RR (95% CI) | Low MD (n) |
High MD (n) |
RR (95% CI) |
Low MD (n) |
High MD (n) |
RR (95% CI) |
Low MD (n) |
High MD (n) |
RR (95% CI) |
Low MD (n) |
High MD (n) |
RR (95% CI) |
Low MD (n) |
High MD (n) |
RR (95% CI) | |
| Full cohort b | |||||||||||||||||||||
| <25 | 27,429 | 47,253 | (ref) | 88 | 171 | (ref) | 268 | 1,175 | (ref) | 95 | 200 | (ref) | 1,189 | 2,657 | (ref) | 17 | 55 | (ref) | 25,772 | 42,995 | (ref) |
| ≥25-<30 | 30,502 | 21,105 | 0.68 (0.68, 0.69) |
112 | 92 | 0.70 (0.59, 0.84) |
132 | 173 | 0.71 (0.65, 0.79) |
156 | 115 | 0.64 (0.55, 0.74) |
1,558 | 1,443 | 0.71 (0.68, 0.74) |
38 | 43 | 0.70 (0.55, 0.89) |
28,506 | 19,239 | 0.68 (0.67, 0.69) |
| ≥30 | 25,461 | 9,054 | 0.43 (0.42, 0.44) |
130 | 38 | 0.35 (0.26, 0.46) |
48 | 32 | 0.52 (0.39, 0.68) |
187 | 68 | 0.40 (0.32, 0.50) |
1,333 | 611 | 0.47 (0.44, 0.50) |
85 | 33 | 0.38 (0.28, 0.52) |
23,678 | 8,272 | 0.43 (0.42, 0.44) |
| p-trend | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | ||||||||||||||
| p-heterogeneityc | 0.12 | ||||||||||||||||||||
| Ages <45 d | |||||||||||||||||||||
| <25 | 5,493 | 17,652 | (ref) | 26 | 65 | (ref) | 60 | 488 | (ref) | 20 | 79 | (ref) | 389 | 1,269 | (ref) | * | 24 | (ref) | 4,993 | 15,727 | (ref) |
| ≥25-<30 | 5,250 | 5,811 | 0.69 (0.68, 0.71) |
24 | 30 | 0.80 (0.61, 1.06) |
23 | 68 | 0.83 (0.73, 0.94) |
32 | 56 | 0.80 (0.66, 0.97) |
483 | 625 | 0.74 (0.69, 0.78) |
* | 19 | 0.80 (0.59, 1.07) |
4,681 | 5,013 | 0.68 (0.67, 0.70) |
| ≥30 | 4,975 | 2,388 | 0.43 (0.41, 0.44) |
29 | 16 | 0.50 (0.33, 0.76) |
* | * | 0.56 (0.34, 0.94) |
46 | 27 | 0.46 (0.33, 0.63) |
426 | 243 | 0.47 (0.42, 0.52) |
29 | * | 0.34 (0.21, 0.54) |
4,438 | 2,082 | 0.42 (0.41, 0.44) |
| p-trend | <0.001 | 0.016 | 0.002 | <0.001 | <0.001 | 0.004 | <0.001 | ||||||||||||||
| p-heterogeneityc | 0.009 | ||||||||||||||||||||
| Ages 45 to <55 b | |||||||||||||||||||||
| <25 | 7,730 | 16,752 | (ref) | 27 | 63 | (ref) | 80 | 445 | (ref) | 34 | 74 | (ref) | 461 | 1057 | (ref) | * | * | (ref) | 7,121 | 15,091 | (ref) |
| ≥25-<30 | 8,623 | 7,613 | 0.70 (0.68, 0.71) |
35 | 44 | 0.80 (0.63, 1.02) |
51 | 59 | 0.63 (0.53, 0.75) |
62 | 37 | 0.56 (0.43, 0.75) |
634 | 611 | 0.71 (0.66, 0.75) |
* | * | 0.69 (0.46, 1.03) |
7,829 | 6,846 | 0.70 (0.68, 0.71) |
| ≥30 | 8,241 | 3,460 | 0.44 (0.43, 0.45) |
57 | * | 0.27 (0.16, 0.45) |
22 | 15 | 0.47 (0.31, 0.70) |
73 | 27 | 0.39 (0.28, 0.56) |
553 | 273 | 0.48 (0.43, 0.53) |
29 | 16 | 0.44 (0.28, 0.70) |
7,507 | 3,116 | 0.44 (0.42, 0.45) |
| p-trend | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.015 | <0.001 | ||||||||||||||
| p-heterogeneityc | 0.14 | ||||||||||||||||||||
| Ages ≥55 b | |||||||||||||||||||||
| <25 | 14,206 | 12,849 | (ref) | 35 | 43 | (ref) | 128 | 242 | (ref) | 41 | 47 | (ref) | 339 | 331 | (ref) | * | * | (ref) | 13,658 | 12,177 | (ref) |
| ≥25-<30 | 16,629 | 7,681 | 0.67 (0.66, 0.69) |
53 | 18 | 0.44 (0.27, 0.70) |
58 | 46 | 0.68 (0.55, 0.86) |
62 | 22 | 0.47 (0.32, 0.70) |
441 | 207 | 0.64 (0.56, 0.74) |
19 | * | 0.45 (0.21, 0.98) |
15,996 | 7,380 | 0.67 (0.66, 0.69) |
| ≥30 | 12,245 | 3,206 | 0.44 (0.42, 0.45) |
44 | * | 0.30 (0.16, 0.55) |
* | * | 0.55 (0.33, 0.91) |
68 | 14 | 0.30 (0.18, 0.51) |
354 | 95 | 0.42 (0.35, 0.51) |
27 | * | 0.24 (0.09, 0.64) |
11,733 | 3,074 | 0.44 (0.42, 0.45) |
| p-trend | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | 0.08 | <0.001 | ||||||||||||||
| p-heterogeneityc | 0.24 | ||||||||||||||||||||
Abbreviations: AIAN=non-Hispanic American Indian or Alaska Native; Asian=non-Hispanic Asian; Black=non-Hispanic Black; NHPI=non-Hispanic Native Hawaiian or Pacific Islander; White=non-Hispanic White
Consistent with Utah Population Database confidentiality policies, we have masked low counts (n<11) and any counts that could be used to re-create the low counts.
Low MD is defined as BI-RADS A or B, and high MD defined as BI-RADS C or D.
Multivariable models are adjusted for age (continuous), education (less than high school or high school diploma, more than high school, missing), parity (0 births in Utah, 1 birth in Utah, 2+ births in Utah, parous with number of births not known), and hormone therapy (HT) use (never, past, current). The model for the full population, “All,” is additionally adjusted for the combined race and ethnicity variable.
The test for heterogeneity is a likelihood ratio test comparing models with and without interaction terms between the combined race and ethnicity variable and BMI.
Multivariable models are adjusted for age (continuous), education (less than high school or high school diploma, more than high school, missing), and parity (0 births in Utah, 1 birth in Utah, 2+ births in Utah, parous with number of births not known). The model for the full population, “All,” is additionally adjusted for the combined race and ethnicity variable.