Table 1. Studies of the Urinary 2/16 Estrogen Metabolite Ratio in Healthy Populations of Women.
| Study reference |
Main Topic of the study |
N£ | Race | Age (years) |
Menopausal Status |
Assay | # Measures; methods of urine collection |
2/16 ratio | Statistics presented |
Main analyses in the original paper |
|---|---|---|---|---|---|---|---|---|---|---|
| 96, 97^ | Dietary fiber/multiethnic |
23 | White | 31.7/34.6 | Pre | GC-MS | 2; 72 hrs, mid follicular. |
2.0 | GM, SE | Diet groups |
| 52 | HRT | 34 | N/A | N/A | Post | ELISA | 1; spot | 2.71 ± 0.84 | Mean, SD | HRT & overall |
| 53 | HRT | 174 | White | Median: 60 | Post | ELISA | 1; 24 hrs | 2.74 ± 0.24 | Mean, SE | HRT |
| 54, 55 | Equol excretion | 61 | White/Asian/AA | 25-59 | Pre, Post | ELISA | 1; overnight | 1.45 (0.4-5.6) | GM, range |
Overall |
| 56, 57 | Physical activity intervention |
173 | 86% White | 50-75 | Post | ELISA | 3; spot | 1.15 (1.03-1.29) | GM, range |
Baseline, after intervention |
| 58 | Soy intervention | 187 | Mostly whites | Median: 42 | Pre | ELISA | 1; morning, day 5-9 of cycle |
1.42 (1.3-1.6) | GM, 95% CI |
Baseline,after soy load |
| 59 | Physical activity | 77 | White | 18-51 | Pre | ELISA | 1; first morning |
1.82 ± 0.13 | Mean, SE | Overall |
| 98 | Smoking, HRT treatment |
16 | N/A | N/A | Post | GS MS | 2; 24 hrs | NS: 1.23 ± 0.32; SMK:1.62 ±0.45 |
Mean, SD | Smoking |
| 60 | Methodology on volunteers |
511 | Multiracial | 17-35 | Pre | ELISA | 1; morning., Phase of cycle recorded |
White: 1.67 AA: 1.69 Asian: 1.25 Indian: 1.51 |
Median, interquarti le range+ |
urine versus plasma |
| 49 | Assay validation | 214 | N/A | N/A | Pre, Post | ELISA | Several, morning spot follicular phase |
Pre: 2.3±0.6 Post: 1.5± 0.4 |
Mean, SD | Menopausal |
| 61, 62 | Aerobic fitness | 30& | White | 20-42 | Pre | ELISA | 2; first morning, luteal |
1.86$ | Mean, 95% CI |
Fitness, Menstrual cycle |
| 63 | Methods | 10 | White | 23-58 | Pre, Post | ELISA | 8; first morning, days 23-31of cycle |
2.03 ± 0.32$ | Individual values |
|
| 104 | Case/control | 58 | White, AA | N/A | Pre, Post | N/A | N/A | W: 2.2 ± 1.3 AA: 1.8 ± 1.1 |
Mean, SD | |
| 64 | Descriptive multi- geographic Asian populations |
511 | Asian | 25-55 | Pre, Post | ELISA | 1; overnight, day of menstrual cycle recorded |
Premeno: China 1.89; Japan: 1.67; Philippines:1.31 Postmeno: China 1.71; Japan 1.68; Philippines 1.8 |
GM | Menopausal status |
| 65, 66* | Dietary factors; Brassica trial |
37 | White | >45 | Post | ELISA | 2; 24 hrs | 2.35 ± 1.33 | Mean, SD | Overall and by intervention |
| 4 | Family history of breast cancer |
64 | 91% white | Median: 50 | Pre, Post | ELISA | 1; spot | 2.13$ (Pre: 2.1 ± 0.8; Post: 2.2 ± 0.7) |
Mean, SD | Menopause & age |
| 67 | Flaxseed | 15 | mostly white | 20-38 | Pre | ELISA | 3; 24 hrs, mid- luteal |
2.26 ± 0.19 | Mean, SE | Diet group |
| 68 | Case/control | 36 | Asian | Median: 54.8 | Pre, post | ELISA | 1; overnight | 2.0 ± 0.3 | Mean, SE | |
| 69 | Case/control | 64 | Multiracial | Median: 54.2 | Pre, post | ELISA | 1;spot | 1.72 ± 0.66 | Mean, SD | Menopausal |
| 70 | Case control | 326 | White, AA | N/A | Pre, post | ELISA | 1;spot | Pre: 1.9 ±1.0; post: 2.0 ± 1.0 |
Mean, SD | |
| 99# | Osteopenia, Bone density |
59 | Korean | 55-60 | Post | GC-MS | 1; overnight | 0.17; 0.1# | Mean, SE | Bone density |
| 71 | Soy, isoflavones | 85 | Mostly Asian | Median: 33 | Pre | ELISA | Daily; 12 hrs | 2.0 ± 0.32 | Mean, SE | Diet |
| 72** | Bone density | 71 | N/A | 47-59 | Post | ELISA | 1; 24 hrs | 2.85 ± 1.73 | Mean, SD | Bone density |
| 73 | Soy intake | 16 | N/A | 18-40 | Pre | ELISA | 2; 48 hrs, mid luteal & mid follicular |
2.32 ± 1.11 | Mean, SD | Diet & OC use |
| 74 | Blood pressure | 54 | White/AA/Latino | 50-67 | Post | ELISA | 1; overnight | 1.5 | Mean | HRT status |
| 75 | Flax, genes | 132 | 97% white | 45-75 | Post | ELISA | 2; morning spot |
1.54 ± 0.75 | Mean, SD | Overall |
| 5, 76* | Physical activity | 146 | Chinese | 47.1 | Pre, Post | ELISA | 2; overnight | 1.2 ± 1.0 | Mean, SD | Race |
| 77 | Cancer incidence | 296 | N/A | >35 | Pre, Post | ELISA | 1; spot | Pre: 2.1; Post: 1.7 |
Median | Menopausal |
| 78, 79# | OC & HRT | 67, 63 | N/A | Median: Pre= 26; Pos=55 |
Pre, Post | ELISA | 2; 8 hrs overnight |
Pre: 1.6 ± 0.12; 1.5 ± 0.1 Post: 2.1 ± 0.18; 1.67 ± 0.13 |
Mean, 95% CI |
Pre & Post HRT or OC |
| 80, 81# | Various hormonal treatment groups |
74 | N/A | Median: 54 | Post | ELISA | 2; 8hrs overnight |
1.15 ± 0.14; 1.5 ± 0.22; 1.2 ± 0.1; 2.0 ± 0.04 |
Mean, 95%CI |
HRT |
| 82, 83** | Genes/ bone density | 156 | White | Median: 63.5 | Post | ELISA | 1; 24 hrs | 2.1 ± 0.13 | Mean, SE | Genotype |
| 84 | Soy intake in cancer survivors |
20 | N/A | Median: 56.2 | Post | ELISA | 4; 24 hrs | 1.92 (1.61-2.29) | GM, 95% CI |
Overall, survivors, controls |
| 85 | Low fat diet, physical activity |
174 | Mostly White | 44-50 | Pre | ELISA | 2; spot | 2.3 ± 1.1 | Mean, SD | Treatment group |
| 86 | Breast density | 140 | White | 40-65 | Post | ELISA | 1; N/A | 0.98 (0.59-1.28) | Mean, range |
Breast density |
| 100 | Sedentary and Physical Activity |
15 | N/A | Median: 29 | Pre | GS MS | 3; 24 hrs | 0.93 ± 0.62 | Mean, SD | Intervention |
| 87, 6 | Diet &lifestyle | 1881 | AA/White/Asian/ Hispanic |
45-54 | Pre, Peri | ELISA | 1; overnight, mostly follicular |
AA: 1.65 ± 0.05 White:2.1 ± 0.04 China:1.9 ± 0.12 Hisp.:1.95±0.14 Japan:1.92± 0.09 |
Mean, SE | Race |
| 88, 89 | Multiethnic | 33 | White/AA | 18-73 | Pre, Post | ELISA | 1; morning | White:2.25±0.89 AA: 1.42 ± 0.61 |
Mean, SD | Race |
| 90, 91 | Multiethnic (pilot) |
125 23 |
Chinese, AA, White |
45-75 55-64 |
Post | ELISA | 1; morning | Chinese:1.63 (1.41-1.89); White+AA: 1.48 (1.27-1.84); 1.58 ± 0.2 |
GM 95% CI Mean, SE |
Race Breast cancer |
| 92 | Family history of breast cancer |
97 | White | 20-50 | Pre | ELISA | 1; morning, 5- 9 days of cycle |
1.82 (1.49-2.15) | GM 95% CI |
Family history |
| 93, 94 | Diet & exercise | 24 | N/A | Median: 31.5 | Pre | ELISA | 5; morning, mid follicular and mid luteal |
1.95 ± 0.18 | Mean, SE | Menstrual phase |
| 95 | Case/control | 426 | White | 50-64 | Pre, Post | ELISA | 1; spot | 1.6 (0.3-0.5); | Median + (5-95%) |
HRT |
| 101, 102 | Menstrual cycle, soy isoflavones |
12 | N/A | Median: 26 | Pre | GC-MS | 3; 24 hrs | 18 ± 3.92 | Mean, SD | Diet, menstrual cycle |
| 103 | Soy diets | 18 | N/A | Median: 56.9 | Post | GC-MS | 2; 24 hrs | 1.33 ± 0.08 | Mean, SE | Overall & diet |
Abbreviations: GC-MS=Gas chromatography mass spectrometry, ELISA=Enzyme -linked immunosorbent assay, RIA=Radiometric ImmunoAssay, N/A=not indicated in publication, AA=African American, HRT=hormone replacement therapy, OC=oral contraceptive, NS=non-smokers, SMK=smokers; GM=geometric mean, SD=standard deviation, SE=standard error, CI=confidence intervals
£
Number of subjects in control or non-treatment groups
^
ratio reported only on a subset of the various populations included
**
Partial overlap, 26 Whites were included in ref 83; (new data: 45)
+
mean was calculated from median; SD from ranges when full ranges were available
#
16/2 is reported in the original paper
&
(3 on OC, 1 on HRT)
$
overall mean over 4 menstrual cycles was re-calculated