Table 1.
Survey-weighted characteristics of study participants by cataract status, NHANES, 1999–2008.
| Characteristics | total samples | Ever had cataract operation
|
P-valueb | |
|---|---|---|---|---|
| Yes | No | |||
| Total sample, N (%) | 9763 (100) | 1737 (14.1) | 8026 (85.9) | |
| Age, years | 63.2 ± 0.2 | 74.1 ± 0.3 | 61.4 ± 0.2 | <.001 |
| Female, n (%) | 4887 (53.3) | 947 (61.7) | 3940 (51.9) | <.001 |
| Race/ethnicity, n (%) | ||||
| Non-Hispanic White | 5640 (80.3) | 1221 (85.8) | 4419 (79.3) | <.001 |
| Mexican American | 1675 (3.9) | 196 (2.3) | 1479 (4.1) | |
| Non-Hispanic Black | 1667 (8.1) | 203 (5.9) | 1464 (8.5) | |
| Other | 781 (7.8) | 117 (6.0) | 664 (8.0) | |
| Education, n (%) | ||||
| <high school | 3362 (21.9) | 690 (31.0) | 2672 (20.4) | <.001 |
| High school | 2358 (26.7) | 420 (27.5) | 1938 (26.5) | |
| Some college+ | 4043 (51.4) | 627 (41.5) | 3416 (53.1) | |
| Diabetes, n (%) | 1774 (14.0) | 421 (22.1) | 1353 (12.7) | <.001 |
| Body mass index, kg/m2 | 28.8 ± 0.1 | 28.1 ± 0.2 | 28.9 ± 0.1 | <.001 |
| Pack-years, n (%) | ||||
| 0 | 4758 (48.2) | 843 (47.6) | 3915 (48.3) | 0.006 |
| >0 and <20 | 2481 (24.7) | 376 (21.7) | 2105 (25.2) | |
| ≥20 | 2524 (27.0) | 518 (30.7) | 2006 (26.4) | |
| Smoking status, n (%) | ||||
| Non-smoker | 4694 (47.5) | 826 (46.7) | 3868 (47.7) | <.001 |
| Former smoker | 3605 (36.5) | 746 (43.7) | 2859 (35.3) | |
| Current smoker | 1464 (16.0) | 165 (9.6) | 1299 (17.0) | |
| Serum cotinine, ng/dLa | 0.24 (0.21, 0.28) | 0.12 (0.10, 0.14) | 0.27 (0.22, 0.32) | <.001 |
| Blood lead, μg/dLa | 1.94 (1.90, 1.99) | 2.05 (1.98, 2.13) | 1.93 (1.88, 1.97) | <.001 |
| Blood cadmium, μg/Lac | 0.45 (0.43, 0.46) | 0.48 (0.46, 0.49) | 0.44 (0.43, 0.46) | <.001 |
|
| ||||
| Urinary sub-sample, N (%) | 3175 (100) | 587 (14.6) | 2588 (85.4) | |
| Blood lead, μg/dLa | 1.97 (1.92, 2.03) | 2.10 (1.96, 2.24) | 1.95 (1.90, 2.01) | 0.041 |
| Blood cadmium, μg/La | 0.45 (0.43, 0.46) | 0.51 (0.48, 0.54) | 0.44 (0.42, 0.45) | <.001 |
| Urinary cadmium, μg/La | 0.34 (0.32, 0.36) | 0.40 (0.36, 0.43) | 0.33 (0.31, 0.35) | <.001 |
| Urinary creatinine, mg/dLa | 81.3 (78.4, 84.4) | 75.2 (69.6, 81.2) | 82.5 (79.1, 86.0) | <.001 |
a
Geometric mean (95% confidence interval) is presented because of skewness
b
P-value based on t-tests for continuous variables and Rao-Scott Chi-squared tests for categorical variables.
c
SI conversion factors: To convert blood cadmium to nmol/L, multiply values by 8.896.