Table 2.
Prevalence Ratios and 95% CIs for Preeclampsia in Relationship to Concentrations of Trace Minerals and Heavy Metals in RBCs, Before and After Adjustment for Potential Confounders (n=1274)
| n | Cases (%) | Model 1a | Model 2b | |||
|---|---|---|---|---|---|---|
| PR (95% CI) | P Value | PR (95% CI) | P Value | |||
| RBC manganese (μg/L)c | ||||||
| Quintile 1 (6.86–27.00) | 248 | 33 (13.3%) | Ref. | Ref. | ||
| Quintile 2 (27.20–33.80) | 250 | 26 (10.4%) | 0.78 (0.48–1.27) | 0.32 | 0.75 (0.46–1.23) | 0.25 |
| Quintile 3 (34.00–41.20) | 246 | 25 (10.2%) | 0.76 (0.47–1.24) | 0.28 | 0.68 (0.41–1.11) | 0.12 |
| Quintile 4 (41.40–51.80) | 244 | 16 (6.6%) | 0.49 (0.28–0.87) | 0.01 | 0.46 (0.26–0.81) | 0.008 |
| Quintile 5 (52.00–109.80) | 244 | 11 (4.5%) | 0.34 (0.17–0.65) | 0.003 | 0.33 (0.17–0.65) | 0.001 |
| P trend | <0.001 | <0.001 | ||||
| Per 1 SD (15.52) increment | N.A. | 0.70 (0.57–0.86) | 0.001 | 0.68 (0.54–0.86) | 0.001 | |
| RBC selenium (μg/L) | ||||||
| Quintile 1 (129.22–241.12) | 255 | 22 (8.6%) | Ref. | Ref. | ||
| Quintile 2 (242.00–264.00) | 269 | 23 (8.5%) | 0.99 (0.57–1.73) | 0.97 | 0.94 (0.54–1.63) | 0.82 |
| Quintile 3 (266.00–290.00) | 243 | 28 (11.5%) | 1.33 (0.79–2.27) | 0.28 | 1.31 (0.77–2.22) | 0.32 |
| Quintile 4 (291.51–326.00) | 257 | 21 (8.2%) | 0.95 (0.53–1.68) | 0.85 | 0.93 (0.51–1.68) | 0.80 |
| Quintile 5 (328.00–624.00) | 250 | 21 (8.4%) | 0.97 (0.55–1.72) | 0.93 | 0.93 (0.52–1.66) | 0.80 |
| P trend | 0.89 | 0.81 | ||||
| Per 1 SD (61.55) increment | N.A. | 0.95 (0.79–1.13) | 0.54 | 0.93 (0.78–1.12) | 0.46 | |
| RBC cadmium (μg/L) | ||||||
| Quintile 1 (0.04–0.39) | 256 | 17 (6.6%) | Ref. | Ref. | ||
| Quintile 2 (0.40–0.59) | 256 | 18 (7.0%) | 1.06 (0.56–2.01) | 0.86 | 1.09 (0.58–2.06) | 0.77 |
| Quintile 3 (0.59–0.80) | 253 | 24 (9.5%) | 1.43 (0.79–2.59) | 0.24 | 1.48 (0.81–2.71) | 0.21 |
| Quintile 4 (0.80–1.18) | 255 | 31 (12.2%) | 1.83 (1.04–3.22) | 0.04 | 1.97 (1.08–3.59) | 0.03 |
| Quintile 5 (1.19–4.76) | 254 | 25 (9.8%) | 1.48 (0.82–2.68) | 0.19 | 1.86 (0.98–3.50) | 0.06 |
| P trend | 0.04 | 0.009 | ||||
| Per 1 SD (0.69) increment | N.A. | 1.03 (0.90–1.19) | 0.65 | 1.15 (0.98–1.36) | 0.09 | |
| RBC lead (μg/dL) | ||||||
| Quintile 1 (0.58–1.56) | 255 | 22 (8.6%) | Ref. | Ref. | ||
| Quintile 2 (1.57–2.10) | 258 | 22 (8.5%) | 0.99 (0.56–1.74) | 0.97 | 1.05 (0.59–1.85) | 0.87 |
| Quintile 3 (2.12–2.80) | 254 | 26 (10.2%) | 1.19 (0.69–2.04) | 0.53 | 1.19 (0.68–2.10) | 0.54 |
| Quintile 4 (2.81–4.28) | 253 | 23 (9.1%) | 1.05 (0.60–1.84) | 0.85 | 1.03 (0.57–1.88) | 0.91 |
| Quintile 5 (4.30–24.80) | 254 | 22 (8.7%) | 1.00 (0.57–1.77) | 0.99 | 0.90 (0.48–1.68) | 0.74 |
| P trend | 0.99 | 0.75 | ||||
| Per 1 SD (3.07) increment | N.A. | 0.95 (0.80–1.13) | 0.57 | 0.91 (0.74–1.11) | 0.36 | |
| RBC mercury (μg/L) | ||||||
| Quintile 1 (0.30–0.89) | 255 | 23 (9.0%) | Ref. | Ref. | ||
| Quintile 2 (0.90–1.60) | 256 | 23 (9.0%) | 1.00 (0.57–1.73) | 0.99 | 0.94 (0.54–1.61) | 0.82 |
| Quintile 3 (1.59–2.58) | 254 | 17 (6.7%) | 0.74 (0.41–1.35) | 0.33 | 0.69 (0.38–1.26) | 0.23 |
| Quintile 4 (2.60–4.28) | 257 | 21 (8.2%) | 0.91 (0.51–1.59) | 0.73 | 0.84 (0.47–1.49) | 0.55 |
| Quintile 5 (4.30–27.80) | 252 | 31 (12.3%) | 1.36 (0.82–2.27) | 0.23 | 1.21 (0.72–2.05) | 0.47 |
| P trend | 0.34 | 0.58 | ||||
| Per 1 SD (3.60) increment | N.A. | 1.06 (0.92–1.22) | 0.45 | 1.03 (0.88–1.20) | 0.71 | |
N.A. indicates not applicable; PR, prevalence ratio; RBC, red blood cell; Ref, reference group.
a
Model 1 was an unadjusted model.
b
Model 2 was adjusted for age at delivery (continuous), self‐reported race (black, nonblack), education (below high school, high school, college or above), parity (nulliparous, multiparous), prepregnancy body mass index (continuous), and smoking status during pregnancy (never, former, current).
c
There are 42 missing values for manganese (n=1232).