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Table 2 Participant characteristics by frequency of green tea intake

From: Green tea intake is associated with urinary estrogen profiles in Japanese-American women

  Less than weekly intake (< once per week) Weekly intake (1-6 times per week) Daily intake (7+ times per week) P value*
  mean s.d. mean s.d. mean s.d.  
Age (y)* 45.4 6.8 48.3 8.2 49.7 7.0 0.01
Body Mass Index (kg / m 2 ) 21.9 3.3 22.0 3.1 21.0 2.8 0.18
  n row % n row % n row %  
Menopausal status / menstrual phase        0.049
Premenopausal women in luteal phase 62 52.1% 32 26.9% 25 21.0%  
Postmenopausal 25 34.7% 23 31.9% 24 33.3%  
Study center, n (%)        0.01
Hawaii 70 55.1% 34 26.8% 23 18.1%  
Los Angeles 7 21.9% 13 40.6% 12 37.5%  
San Francisco 10 31.3% 8 25.0% 14 43.8%  
Combined parity and age at first birth, n (%)        0.07
Nulliparous 12 42.9% 8 28.6% 8 28.6%  
1st birth age ≤ 20 y 7 63.6% 4 36.4% 0 .0%  
1-2 live births / age ≥ 21 53 52.5% 23 22.8% 25 24.8%  
3+ live births / age ≥ 21 15 29.4% 20 39.2% 16 31.4%  
Age at menarche, n (%)        <0.001
≥ 12 y 56 54.9% 34 33.3% 12 11.8%  
> 12 y 31 34.8% 21 23.6% 37 41.6%  
Born in Asia, n (%)        <0.001
No 74 49.3% 49 32.7% 27 18.0%  
Yes 13 31.7% 6 14.6% 22 53.7%  
Soy intake (frequency of weekly intake), n (%)        <0.001
0-0.5 times weekly 31 66.0% 12 25.5% 4 8.5%  
0.5-1 times weekly 27 47.4% 20 35.1% 10 17.5%  
> once weekly 29 33.3% 23 26.4% 35 40.2%  
Black tea (frequency of weekly intake), n (%)        0.21
< once weekly 69 50.7% 34 25.0% 33 24.3%  
1-6 times weekly 12 32.4% 15 40.5% 10 27.0%  
7+ times weekly 6 33.3% 6 33.3% 6 33.3%  
Coffee (frequency of weekly intake), n (%)        0.75
0-2 times weekly 22 53.7% 11 26.8% 8 19.5%  
3-13 times weekly 25 41.0% 18 29.5% 18 29.5%  
≥14 times weekly 40 44.9% 26 29.2% 23 25.8%  
Caffeine (weekly intake in mg), n (%)        0.83
0-734 29 50.0% 15 25.9% 14 24.1%  
734-1609 27 47.4% 15 26.3% 15 26.3%  
≥1610 31 40.8% 25 32.9% 20 26.3%  
  1. * For continuous covariates, p-values were obtained using ANOVA and reflect significance of differences between means by categories of green tea intake. For categorical covariates, p-values were obtained using Chi Square tests and reflect differences in distribution.