Table 3.

Multivariate-adjusteda geometric means of estrogen metabolism measures by category of coffee intake

Geometric mean by coffee intake
≤6 cups/wk1 cup/day2–3 cups/day4+ cups/dayPtrend
Individual and grouped EM (pmol/mg creatinine)
Total EM195.5197.0207.2222.70.08
Parent estrogens40.541.841.244.40.37
Methylated catechols11.210.210.410.70.49
 Methylated 2-catechols10.89.810.010.40.46
  2-Hydroxyestrone-3-methyl ether1.
 Methylated 4-catechols0.
2-Hydroxylation pathway64.364.870.790.50.01
4-Hydroxylation pathway7.
16-Hydroxylation pathway65.865.765.861.60.79
Ratios (pmol/pmol)
2-Catechols/methylated 2-catechols4.<0.0001
4-Catechols/methylated 4-catechols25.123.326.229.20.54
Catechols/methylated catechols5.<0.0001
Parent estrogens/2-, 4-, 16-pathways0.
2-Pathway/parent estrogens1.
4-Pathway/parent estrogens0.
16-Pathway/parent estrogens1.
  • aAdjusted for age at urine collection (continuous), BMI at collection (kg/m2, continuous), height (continuous), ovulatory cycle (yes/no), first-morning urine (yes/no), quartiles of alcohol intake (nondrinker, ≤1.49, 1.50–4.85, >4.85 g/day), total physical activity (<3, 3–8.9, 9–17.9, 18–26.9, 27–41.9, ≥42 MET h/week), current tobacco use (yes/no), luteal day (≤5, 6–7, 8–9, ≥10 days to next period), usual menstrual cycle length (<26, 26–31, ≥32 days), menstrual cycle regularity (extremely regular, very regular, regular, usually/always irregular), and age at first birth and parity (nulliparous, age at first birth <25 years/1–2 children, age at first birth 25–29 years/1–2 children, age at first birth ≥30 years/1–2 children, age at first birth <25 years/≥3 children, age at first birth ≥25 years/≥3 children). Numbers do not sum to 603 due to missing values for exposure. Significant Ptrend shown in bold.