TABLE 4.
Multivariable 1 ORs and 95% CIs for intake of total caffeine and frequency of coffee consumption at baseline and specific premenstrual symptoms: Nurses’ Health Study II PMS substudy, 1991–20051
| Breast tenderness |
Irritability |
Fatigue |
||||
| Cases, n | OR (95% CI) | Cases, n | OR (95% CI) | Cases, n | OR (95% CI) | |
| Total caffeine | ||||||
| Q1 | 183 | 1 | 161 | 1 | 122 | 1 |
| Q2 | 190 | 0.95 (0.71, 1.28) | 161 | 0.88 (0.63, 1.23) | 129 | 0.97 (0.68, 1.39) |
| Q3 | 172 | 1.01 (0.74, 1.38) | 148 | 1.06 (0.74, 1.50) | 117 | 1.01 (0.68, 1.50) |
| Q4 | 195 | 1.08 (0.78, 1.49) | 167 | 1.04 (0.73, 1.50) | 126 | 1.22 (0.82, 1.81) |
| Q5 | 165 | 0.83 (0.58, 1.19) | 125 | 0.79 (0.53, 1.19) | 92 | 0.91 (0.58, 1.44) |
| P-trend | 0.58 | 0.30 | 0.80 | |||
| Caffeinated coffee | ||||||
| <1 cup/mo | 347 | 1 | 301 | 1 | 233 | 1 |
| 1 cup/mo–1 cup/wk | 77 | 1.13 (0.78, 1.64) | 66 | 1.17 (0.84, 1.62) | 51 | 1.22 (0.85, 1.74) |
| 2–6 cups/wk | 61 | 0.76 (0.52, 1.12) | 50 | 0.88 (0.62, 1.24) | 40 | 0.82 (0.56, 1.20) |
| 1 cup/d | 119 | 1.12 (0.81, 1.55) | 99 | 1.15 (0.87, 1.52) | 81 | 1.22 (0.90, 1.67) |
| 2–3 cups/d | 220 | 1.02 (0.77, 1.36) | 190 | 1.04 (0.81, 1.33) | 143 | 1.15 (0.87, 1.51) |
| ≥4 cups/d | 69 | 0.73 (0.48, 1.12) | 56 | 0.74 (0.50, 1.10) | 38 | 0.90 (0.59, 1.39) |
| P-trend | 0.44 | 0.37 | 0.96 | |||
| Decaffeinated coffee | ||||||
| <1 cup/mo | 564 | 1 | 485 | 1 | 387 | 1 |
| 1 cup/mo–1 cup/wk | 140 | 1.18 (0.90, 1.56) | 120 | 1.08 (0.84, 1.39) | 82 | 1.05 (0.80, 1.39) |
| 2–6 cups/wk | 65 | 0.99 (0.67, 1.45) | 53 | 0.88 (0.63, 1.24) | 37 | 0.74 (0.50, 1.10) |
| 1 cup/d | 67 | 1.33 (0.90, 1.98) | 57 | 1.34 (0.95, 1.91) | 49 | 1.62 (1.12, 2.33) |
| ≥2 cups/d | 57 | 1.21 (0.78, 1.87) | 47 | 1.10 (0.75, 1.63) | 31 | 0.88 (0.57, 1.37) |
| P-trend | 0.29 | 0.39 | 0.88 | |||
Multivariable logistic regression models adjusted for diagnosis year (1993, 1994–1995, 1996–1997, 1998–1999, or 2000–2001); age; pack-years of smoking (0, 1–5, 6–10, 11–15, 16–20, or ≥21); parity (0, 1–2, 3–4, or ≥5); duration of oral contraceptive use (never or 1–23, 24–71, 72–119, or ≥120 mo); history of childhood trauma score (5, 6–10, 11–15, or ≥16); depression before PMS, depression medication; BMI [in kg/m2 (<20.0, 20.0–22.4, 22.5–24.9, 25.0–27.4, 27.5–29.9, or ≥30)]; physical activity (<3, 3 to <9, 9 to <18, 18 to <27, 27 to <42, or ≥42 metabolic equivalent task–hours/wk); and total intake of alcohol (0, >0 to <5, 5 to <10, 10 to <15, or ≥15 g/d), calcium, vitamin D, vitamin B-6, and potassium. PMS, premenstrual syndrome; Q, quintile.