Table 1.

Characteristics of premenopausal women recruited during annual screening mammogram at Washington University School of Medicine (St. Louis, Missouri) from December 2015 to October 2016 and from September 2020 to February 2022 across PFOS, PFOA, and PFHxS peak area levels from untargeted metabolomics ($n=705$).

Characteristic	$n$ (%)	PFOSa	PFOAb	PFHxSc
		$\text{Mean}\pm \text{SD}$	$\text{Mean}\pm \text{SD}$	$\text{Mean}\pm \text{SD}$
Race
White	506 (72)	$3.48\pm 2.48$	$1.76\pm 1.92$	$1.54\pm 1.15$
Black	163 (23)	$3.28\pm 2.69$	$0.983\pm 0.865$	$1.00\pm 0.99$
Other races	31 (4)	$4.24\pm 5.40$	$2.06\pm 2.65$	$1.60\pm 1.91$
Missing	5 (1)	—	—	—
Age at enrollment
$\le \text{Median}$ (46 years old)	386 (55)	$3.28\pm 2.79$	$1.41\pm 1.16$	$1.35\pm 1.02$
$>\text{Median}$ (46 years old)	319 (45)	$3.73\pm 2.63$	$1.82\pm 2.33$	$1.50\pm 1.33$
Age at menarche
$\le \text{Median}$ (13 years old)	514 (73)	$3.40\pm 2.54$	$1.59\pm 1.92$	$1.39\pm 1.20$
$>\text{Median}$ (13 years old)	189 (27)	$3.70\pm 3.18$	$1.61\pm 1.43$	$1.48\pm 1.09$
Missing	2 (0.3)	—	—	—
Body shape at age 10d
1–2	290 (41)	$3.49\pm 2.76$	$1.55\pm 1.31$	$1.41\pm 1.24$
3–4	237 (34)	$3.51\pm 3.07$	$1.75\pm 2.60$	$1.41\pm 1.06$
5	85 (12)	$3.19\pm 2.04$	$1.30\pm 0.83$	$1.19\pm 0.66$
6–9	53 (8)	$3.24\pm 2.14$	$1.27\pm 0.65$	$1.46\pm 1.13$
Missing	40 (6)	—	—	—
Percentage body fat
$\le \text{Median}$ (40.5%)	334 (47)	$3.64\pm 3.01$	$1.85\pm 2.30$	$1.49\pm 1.14$
$>\text{Median}$ (40.5%)	336 (48)	$3.33\pm 2.41$	$1.36\pm 1.10$	$1.36\pm 1.22$
Missing	25 (4)	$3.48\pm 2.48$	$1.76\pm 1.92$	$1.54\pm 1.15$
Age at first birth
Nulliparous	162 (23)	$3.54\pm 2.28$	$1.65\pm 1.04$	$1.59\pm 1.03$
$\le \text{Median}$ (27 years old)	285 (40)	$3.44\pm 2.94$	$1.55\pm 1.59$	$1.33\pm 1.25$
$>\text{Median}$ (27 years old)	256 (36)	$3.50\pm 2.74$	$1.61\pm 2.32$	$1.41\pm 1.16$
Missing	2 (0.3)	—	—	—
Parity, age at first birth
Nulliparous	162 (23)	$3.54\pm 2.28$	$1.65\pm 1.04$	$1.59\pm 1.03$
1–2 children, $<25\text{\hspace{0.17em}years}$	107 (15)	$3.32\pm 2.32$	$1.44\pm 1.20$	$1.45\pm 1.59$
1–2 children, 25–29 years	111 (16)	$4.23\pm 4.13$	$1.79\pm 1.86$	$1.48\pm 1.07$
1–2 children, $\ge 30\text{\hspace{0.17em}years}$	156 (22)	$3.54\pm 2.67$	$1.64\pm 2.79$	$1.51\pm 1.33$
$\ge 3$ children, $<25\mathrm{years}$	88 (12)	$3.06\pm 2.11$	$1.33\pm 1.18$	$1.13\pm 0.95$
$\ge 3$ children, $\ge 25\mathrm{years}$	79 (11)	$2.93\pm 2.06$	$1.61\pm 1.67$	$1.06\pm 0.58$
Missing	2 (0.3)	—	—	—
Family history of breast cancer
No	540 (77)	$3.42\pm 2.69$	$1.60\pm 1.97$	$1.36\pm 1.08$
Yes	152 (22)	$3.67\pm 2.80$	$1.59\pm 1.03$	$1.61\pm 1.43$
Don’t know	13 (2)	$3.95\pm 3.40$	$1.67\pm 1.08$	$1.52\pm 1.28$
Oral contraceptive use (years)
No	82 (12)	$2.95\pm 2.17$	$1.24\pm 1.09$	$1.10\pm 1.02$
$<1\mathrm{year}$	55 (8)	$3.53\pm 4.57$	$1.51\pm 1.93$	$1.19\pm 0.68$
1–4 years	141 (20)	$3.62\pm 2.71$	$1.46\pm 1.22$	$1.36\pm 1.27$
5–9 years	143 (20)	$2.93\pm 1.98$	$1.55\pm 1.23$	$1.29\pm 0.86$
$>10\mathrm{years}$	281 (40)	$3.85\pm 2.67$	$1.82\pm 2.33$	$1.65\pm 1.33$
Missing	3 (0.4)	—	—	—
Alcohol consumption (drinks/week)
Never	211 (3)	$3.58\pm 3.20$	$1.45\pm 2.58$	$1.16\pm 0.86$
$<1$	181 (26)	$3.45\pm 2.81$	$1.62\pm 1.45$	$1.34\pm 0.92$
1–2	133 (19)	$3.63\pm 2.49$	$1.57\pm 0.97$	$1.66\pm 1.50$
3–5	127 (18)	$3.41\pm 2.20$	$1.71\pm 1.27$	$1.62\pm 1.25$
$6+$	52 (7)	$2.92\pm 1.71$	$1.89\pm 1.77$	$1.45\pm 1.05$
Missing	1 (0.1)	—	—	—
VPD category (%)
$<3.5\%$	35 (5)	$3.22\pm 2.42$	$1.22\pm 0.66$	$1.24\pm 1.08$
$\ge 3.5\%$ and $<7.5\%$	314 (45)	$3.25\pm 2.22$	$1.42\pm 1.10$	$1.38\pm 1.20$
$\ge 7.5\%$ and $<15.5\%$	197 (28)	$3.79\pm 3.03$	$1.64\pm 1.21$	$1.44\pm 1.10$
$\ge 15.5\%$	154 (22)	$3.66\pm 3.28$	$1.97\pm 3.18$	$1.51\pm 1.24$
Missing	5 (0.7)	—	—	—
Overall	—	$3.48\pm 2.72$	$1.59\pm 1.80$	$1.42\pm 1.17$

Note: Peak area data for PFOS, PFOA, and PFHxS are presented as $\text{means}\pm \text{standard}$ deviations by participant characteristics. Presented values are $\times {10}^6$. Presented values were ComBat normalized to reduce bias from batch effect, and the missing PFAS values were imputed. The missing PFAS observations, prior to imputation, are presented below. —, no data; DV, dense volume; NDV, nondense volume; PFAS, per- and polyfluoroalkyl substances; PFHxS, perfluorohexane sulfonate; PFOA, perfluorooctanoic acid; PFOS, perfluorooctane sulfonate; VPD, volumetric percent density.

^a Missing PFAS [$n$ (%)] observations: PFOS [1(0.1)].

^b Missing PFAS [$n$ (%)] observations: PFOA [2(0.3)].

^c Missing PFAS [$n$ (%)] observations: PFHxS [9(1)].

^d Self-reported based on Stunkard pictogram.