TABLE 1.
Sociodemographic description of ENDO study participants by sample and quartile of total phytoestrogen concentrations1
| Operative sample2 |
General sample3 |
|||||||||||
| Characteristics | Overall | Q1 | Q2 | Q3 | Q4 | P | Overall | Q1 | Q2 | Q3 | Q4 | P |
| n | 494 | 123 | 124 | 124 | 123 | 131 | 32 | 33 | 33 | 33 | ||
| Age, y | 33 ± 7 | 34 ± 7 | 33 ± 7 | 31 ± 7 | 33 ± 7 | 0.03 | 32 ± 8 | 32 ± 7 | 34 ± 6 | 32 ± 9 | 31 ± 8 | 0.42 |
| BMI, kg/m2 | 28 ± 8 | 30 ± 8 | 29 ± 8 | 27 ± 7 | 27 ± 7 | 0.03 | 27 ± 7 | 28 ± 6 | 27 ± 6 | 27 ± 8 | 26 ± 7 | 0.69 |
| Age at menarche, y | 13 ± 2 | 13 ± 2 | 13 ± 2 | 13 ± 2 | 13 ± 2 | 0.61 | 13 ± 2 | 13 ± 2 | 13 ± 1 | 12 ± 1 | 13 ± 2 | 0.66 |
| Self-identified race/ethnicity | 0.18 | 0.14 | ||||||||||
| Hispanic | 68 (14) | 15 (12) | 11 (9) | 23 (19) | 19 (15) | 14 (11) | 4 (13) | 2 (6) | 6 (18) | 2 (6) | ||
| Non-Hispanic white | 369 (75) | 98 (80) | 102 (82) | 84 (68) | 85 (69) | 106 (82) | 25 (78) | 29 (88) | 24 (73) | 28 (85) | ||
| Non-Hispanic black | 8 (2) | 0 (0) | 2 (2) | 2 (2) | 4 (3) | 2 (2) | 0 (0) | 0 (0) | 2 (6) | 0 (0) | ||
| Asian, Pacific Islander, or American Indian | 29 (6) | 5 (4) | 4 (3) | 9 (7) | 11 (9) | 5 (4) | 3 (9) | 0 (0) | 0 (0) | 2 (6) | ||
| Other or multiracial | 20 (4) | 5 (4) | 5 (4) | 6 (5) | 4 (3) | 4 (3) | 0 (0) | 2 (6) | 1 (3) | 1 (3) | ||
| Married or living as married | 370 (76) | 93 (76) | 103 (83) | 87 (71) | 87 (73) | 0.11 | 78 (60) | 20 (63) | 24 (73) | 17 (52) | 17 (52) | 0.23 |
| Education | 0.002 | 0.29 | ||||||||||
| ≤High school or equivalent | 98 (20) | 37 (30) | 24 (19) | 19 (16) | 18 (15) | 13 (10) | 6 (19) | 4 (12) | 1 (3) | 2 (6) | ||
| Some college or vocational school | 197 (40) | 47 (38) | 50 (40) | 60 (49) | 40 (33) | 58 (44) | 14 (44) | 16 (48) | 16 (48) | 12 (36) | ||
| ≥College graduate | 195 (40) | 39 (32) | 50 (40) | 43 (35) | 63 (52) | 60 (46) | 12 (38) | 13 (39) | 16 (48) | 19 (58) | ||
| Household income | 0.51 | 0.86 | ||||||||||
| Below poverty line | 55 (11) | 13 (11) | 11 (9) | 19 (15) | 12 (10) | 16 (12) | 6 (19) | 2 (6) | 4 (12) | 4 (12) | ||
| Within 180% of poverty line | 58 (12) | 19 (16) | 13 (11) | 12 (10) | 14 (12) | 17 (13) | 4 (13) | 4 (13) | 5 (15) | 4 (12) | ||
| Above poverty line | 373 (76) | 89 (74) | 99 (80) | 92 (75) | 93 (78) | 92 (75) | 22 (69) | 26 (81) | 24 (73) | 25 (76) | ||
| Multi- or prenatal vitamins taken >1 time/wk in past 3 mo | 240 (49) | 61 (50) | 58 (47) | 61 (49) | 60 (49) | 0.97 | 66 (50) | 17 (53) | 18 (55) | 10 (30) | 21 (64) | 0.05 |
| Soy products taken >1 time/wk in past 3 mo | 31 (6) | 4 (3) | 2 (2) | 6 (5) | 19 (15) | <0.0001 | 13 (10) | 3 (9) | 2 (6) | 1 (3) | 7 (21) | 0.07 |
| Physical activity | 0.81 | 0.13 | ||||||||||
| Low | 78 (18) | 21 (20) | 17 (15) | 19 (17) | 21 (19) | 20 (16) | 2 (7) | 9 (30) | 6 (18) | 3 (10) | ||
| Moderate | 161 (37) | 42 (40) | 43 (38) | 40 (37) | 36 (32) | 53 (43) | 17 (59) | 11 (37) | 11 (33) | 14 (45) | ||
| High | 198 (45) | 41 (39) | 53 (47) | 50 (46) | 54 (49) | 50 (41) | 10 (34) | 10 (33) | 16 (48) | 14 (45) | ||
| Smoking status | 0.005 | 0.68 | ||||||||||
| Nonsmoker | 429 (87) | 96 (78) | 107 (86) | 114 (92) | 112 (91) | 117 (89) | 30 (94) | 30 (91) | 29 (88) | 28 (85) | ||
| Current (≥1 cigarette/d) | 65 (13) | 27 (22) | 17 (14) | 10 (8) | 11 (9) | 14 (11) | 2 (6) | 3 (9) | 4 (12) | 5 (15) | ||
| Alcohol | 0.30 | 0.84 | ||||||||||
| None | 384 (78) | 95 (77) | 98 (79) | 102 (82) | 89 (72) | 100 (76) | 24 (75) | 27 (82) | 25 (76) | 24 (73) | ||
| ≥1 drink/wk | 110 (22) | 28 (23) | 26 (21) | 22 (18) | 34 (28) | 31 (24) | 8 (25) | 6 (18) | 8 (24) | 9 (27) | ||
| Mean number of caffeinated beverages consumed/d | 0.04 | 0.97 | ||||||||||
| 0 | 96 (19) | 13 (11) | 32 (28) | 22 (18) | 29 (25) | 44 (34) | 10 (31) | 11 (34) | 10 (31) | 13 (39) | ||
| 1 | 138 (28) | 40 (34) | 28 (25) | 35 (29) | 35 (31) | 43 (33) | 11 (34) | 12 (38) | 10 (31) | 10 (30) | ||
| ≥2 | 229 (46) | 63 (54) | 54 (47) | 62 (52) | 50 (44) | 42 (33) | 11 (34) | 9 (28) | 12 (38) | 10 (30) | ||
Values are means ± SDs or n (%). The respective operative sample concentration ranges for quartiles 1–4 were 7–435, 436–1310, 1320–3670, and 3670–184,000 nmol/L; the respective general population sample concentration ranges were 51–574, 575–1280, 1290–4490, and 4500–62,600 nmol/L. ENDO, Endometriosis, Natural History, Diagnosis, and Outcomes; Q, quartile.
Missing information on age (n = 1), BMI (n = 4), age at menarche (n = 1), marital status (n = 5), educational status (n = 4), income (n = 8), physical activity (n = 57), and caffeinated beverage consumption (n = 31).
Missing information on income (n = 1), physical activity (n = 8), and caffeinated beverage consumption (n = 2).