Table 1 Basic characteristics of study population by tertiles of titanium concentration
Basic characteristics | All participants | Tertiles of SG-corrected titanium (μg/L) | P | ||
|---|---|---|---|---|---|
T1 (≤ 112.35) | T2 (112.35–184.41) | T3 (≥ 184.41) | |||
Participants, n | 1449 | 483 | 483 | 483 | Â |
Study center | |||||
 Nanjing | 1032 (71.2) | 355 (73.5) | 338 (70.0) | 339 (70.2) | 0.399 |
 Suzhou | 417 (28.8) | 128 (26.5) | 145 (30.0) | 144 (29.8) |  |
Maternal age at recruitment, years | 29.57 ± 3.74 | 29.49 ± 3.74 | 29.62 ± 3.79 | 29.61 ± 3.68 | 0.827 |
Pre-pregnancy BMI, kg/m2 | 21.21 (2.87) | 21.13 (2.72) | 21.45 (3.19) | 21.05 (2.65) | 0.068 |
  < 18.5 | 214 (14.8) | 71 (14.7) | 75 (15.5) | 68 (14.1) | 0.042 |
 18.5–23.9 | 1014 (70.0) | 353 (73.1) | 319 (66.0) | 342 (70.8) |  |
 24.0–27.9 | 176 (12.1) | 47 (9.7) | 66 (13.7) | 63 (13.0) |  |
  ≥ 28 | 44 (3.0) | 12 (2.5) | 23 (4.8) | 9 (1.9) |  |
 Missing | 1 (0.1) | 0 (0.0) | 0 (0.0) | 1 (0.2) |  |
Residence area | |||||
 Urban/sub-urban | 1087 (75.0) | 346 (71.6) | 372 (77.0) | 369 (76.4) | 0.107 |
 Rural | 362 (25.0) | 137 (28.4) | 111 (23.0) | 114 (23.6) |  |
Household income, CNY | |||||
  < 100000 | 416 (28.7) | 149 (30.8) | 138 (28.6) | 129 (26.7) | 0.457 |
 100000–200000 | 679 (46.9) | 216 (44.7) | 221 (45.8) | 242 (50.1) |  |
  > 200000 | 353 (24.4) | 118 (24.4) | 123 (25.5) | 112 (23.2) |  |
 Missing | 1 (0.1) | 0 (0.0) | 1 (0.2) | 0 (0.0) |  |
Maternal education, years | |||||
  < 12 | 131 (9.0) | 45 (9.3) | 38 (7.9) | 48 (9.9) | 0.515 |
  ≥ 12 | 1318 (91.0) | 438 (90.7) | 445 (92.1) | 435 (90.1) |  |
Parity | |||||
 0 | 1135 (78.3) | 383 (79.3) | 365 (75.6) | 387 (80.1) | 0.211 |
  ≥ 1 | 313 (21.6) | 100 (20.7) | 117 (24.2) | 96 (19.9) |  |
 Missing | 1 (0.1) | 0 (0.0) | 1 (0.2) | 0 (0.0) |  |
Smoking during pregnancy | 12 (0.8) | 5 (1.0) | 3 (0.6) | 4 (0.8) | 0.777 |
Drinking during pregnancy | 26 (1.8) | 6 (1.2) | 5 (1.0) | 15 (3.1) | 0.028 |
Hypertensive disorders in pregnancya | 48 (3.3) | 22 (4.6) | 15 (3.1) | 11 (2.3) | 0.135 |
75 g oral glucose tolerance test (n = 1360) | |||||
 OGTT screening gestational weeks | 25.22 ± 0.95 | 25.24 ± 0.89 | 25.24 ± 0.93 | 25.18 ± 1.02 | 0.633 |
 FBG, mmol/l | 4.40 ± 0.43 | 4.39 ± 0.41 | 4.38 ± 0.42 | 4.44 ± 0.46 | 0.121 |
 1-h PG, mmol/l | 7.59 ± 1.62 | 7.40 ± 1.57 | 7.68 ± 1.64 | 7.71 ± 1.62 | 0.007 |
 1-h PG, mmol/l | 6.62 ± 1.36 | 6.50 ± 1.34 | 6.66 ± 1.31 | 6.70 ± 1.42 | 0.070 |