Table 1 Characteristics of study population.
From: Association between vitamin B2 intake and female infertility: a cross-sectional study
Characteristic | Total (n = 3804) | Without infertility (n = 3208) | With infertility (n = 524) | P value |
|---|---|---|---|---|
Weighted population | 75,344,429 | 64,445,217 | 10,899,211 | |
Age, mean (SE), years | 39.91 (0.35) | 39.61 (0.34) | 41.65 (0.79) | 0.01 |
Race, n (%) | 0.47 | |||
Mexican American | 581 (10.27%) | 515 (10.64%) | 66 (8.12%) | |
Non-hispanic black | 850 (12.53%) | 740 (12.58%) | 110 (12.21%) | |
Non-hispanic white | 1,386 (60.47%) | 1,163 (59.86%) | 223 (64.06%) | |
Other hispanic | 387 (6.45%) | 341 (6.65%) | 46 (5.31%) | |
Other race | 600 (10.28%) | 521 (10.27%) | 79 (10.30%) | |
Education level, n (%) | 0.41 | |||
Less than high school | 564 (10.27%) | 506 (10.49%) | 58 (8.96%) | |
High school or equivalent | 778 (20.89%) | 677 (21.29%) | 101 (18.53%) | |
Above high school | 2,462 (68.84%) | 2,097 (68.22%) | 365 (72.51%) | |
PIR, Mean (SE) | 2.89 (0.05) | 2.87 (0.06) | 3.01 (0.08) | 0.11 |
Marry, n (%) | < 0.001 | |||
Married | 1,828 (52.27%) | 1,495 (49.96%) | 333 (65.93%) | |
Never married | 892 (21.13%) | 827 (22.86%) | 65 (10.87%) | |
Living with partner | 419 (10.44%) | 374 (10.88%) | 45 (7.84%) | |
Other | 665 (16.17%) | 584 (16.30%) | 81 (15.37%) | |
BMI, mean (SE), kg/m2 | 29.90 (0.27) | 29.53 (0.27) | 32.08 (0.60) | < 0.001 |
BMI, n (%) | 0.09 | |||
< 25 | 1,144 (32.10%) | 1,000 (32.85%) | 144 (27.66%) | |
≥ 25 | 2,660 (67.90%) | 2,280 (67.15%) | 380 (72.34%) | |
Physical activity, mean (SE), min/week | 849.36 (31.92) | 837.83 (32.04) | 917.50 (78.26) | 0.31 |
Smoking status, n (%) | 0.76 | |||
Never | 2,549 (65.16%) | 2,215 (65.45%) | 334 (63.50%) | |
Former | 549 (15.99%) | 463 (15.93%) | 86 (16.33%) | |
Now | 706 (18.85%) | 602 (18.62%) | 104 (20.17%) | |
Drinking status, n (%) | 0.77 | |||
Never | 621 (12.90%) | 544 (12.93%) | 77 (12.76%) | |
Former | 454 (10.85%) | 384 (10.64%) | 70 (12.08%) | |
Mild | 1,053 (28.86%) | 900 (29.42%) | 153 (25.57%) | |
Moderate | 918 (26.87%) | 796 (26.66%) | 122 (28.09%) | |
Heavy | 758 (20.52%) | 656 (20.35%) | 102 (21.49%) | |
HEI-2015, mean (SE) | 51.12 (0.51) | 51.26 (0.55) | 50.29 (0.91) | 0.34 |
Age at menarche, mean (SE) | 12.63 (0.04) | 12.65 (0.04) | 12.53 (0.11) | 0.25 |
Ever treated for a pelvic infection/PID, n (%) | < 0.001 | |||
Yes | 222 (5.66%) | 168 (4.61%) | 54 (11.82%) | |
No | 3,582 (94.34%) | 3,112 (95.39%) | 470 (88.18%) | |
Ever taken birth control pills, n (%) | 0.12 | |||
Yes | 2,683 (76.25%) | 2,282 (75.58%) | 401 (80.23%) | |
No | 1,121 (23.75%) | 998 (24.42%) | 123 (19.77%) | |
Ever use female hormones, n (%) | 0.01 | |||
Yes | 345 (10.74%) | 271 (10.06%) | 74 (14.76%) | |
No | 3,459 (89.26%) | 3,009 (89.94%) | 450 (85.24%) | |
Vitamin B2, mean (SE), mg | 1.87 (0.03) | 1.88 (0.03) | 1.78 (0.04) | 0.047 |
