Table 1.
Characteristics of the study population from the National Health and Nutrition Examination Survey (NHANES) 2017–18 according to quartiles of urinary nickel concentrations
| Urinary nickel quartiles (μg/L) | |||||
|---|---|---|---|---|---|
| Q1 (< 0.65) | Q2 (0.65–1.17) | Q3 (1.17–1.94) | Q4 (> 1.94) | p value | |
| No. Participants | 397 | 396 | 402 | 390 | |
| Age (years) | 48.0 ± 1.56 | 48.2 ± 1.37 | 48.9 ± 0.98 | 50.1 ± 1.51 | 0.31 |
| Gender | |||||
| Male | 47.9 (5.1) | 49.2 (3.7) | 55.1 (3.3) | 44.7 (2.8) | 0.35 |
| Female | 52.1 (5.1) | 50.8 (3.7) | 44.9 (3.3) | 55.3 (2.8) | |
| Race/ethnicity | |||||
| Non-Hispanic white | 64.6 (4.6) | 65.6 (4.1) | 64.1 (3.6) | 54.9 (4.4) | 0.03 |
| Hispanic | 15.3 (1.9) | 16.1 (3.0) | 15.2 (2.8) | 15.7 (2.9) | |
| Non-Hispanic black | 8.1 (1.5) | 9.8 (1.9) | 13.1 (2.8) | 14.4 (1.5) | |
| Other | 12.0 (2.9) | 8.5 (1.8) | 7.7 (1.5) | 15.0 (2.6) | |
| Education | |||||
| Less than high school | 10.0 (1.4) | 9.6 (2.1) | 13.8 (3.0) | 15.2 (2.3) | 0.06 |
| High school | 23.2 (4.2) | 28.3 (3.0) | 34.2 (3.3) | 29.1 (3.7) | |
| College or higher | 66.8 (4.1) | 62.1 (3.8) | 52.0 (4.6) | 55.7 (4.3) | |
| Smoking | |||||
| Never smoker | 54.5 (4.8) | 52.9 (3.6) | 62.8 (5.0) | 54.3 (4.9) | 0.35 |
| Current smoker | 16.5 (2.6) | 14.7 (2.7) | 14.0 (3.0) | 21.2 (3.9) | |
| Past smoker | 29.1 (4.9) | 32.5 (3.8) | 23.2 (3.5) | 24.5 (4.1) | |
| Family income-to-poverty ratio | |||||
| < 1.3 | 14.2 (1.7) | 17.7 (2.2) | 20.8 (2.7) | 23.8 (2.5) | 0.07 |
| 1.3–3.5 | 28.3 (3.9) | 35.0 (3.7) | 29.1 (4.0) | 33.4 (3.6) | |
| ≥ 3.5 | 48.0 (4.3) | 38.4 (5.0) | 36.0 (5.8) | 30.8 (4.6) | |
| Missing | 9.5 (2.2) | 8.8 (1.9) | 14.1 (3.5) | 12.0 (2.5) | |
| Physical activity (MET-min/week) | |||||
| < 600 | 33.0 (3.0) | 30.5 (3.8) | 34.0 (3.5) | 34.9 (2.7) | 0.72 |
| 600–1199 | 10.9 (2.3) | 8.0 (1.9) | 7.7 (1.6) | 7.0 (1.7) | |
| > 1200 | 56.0 (3.2) | 61.5 (3.1) | 57.3 (3.7) | 58.1 (3.0) | |
| Alcohol (g/day) | 11.2 ± 1.62 | 13.1 ± 2.33 | 8.7 ± 1.88 | 8.7 ± 1.05 | 0.04 |
| Total energy intake (kcal/day) | 2227.2 ± 59.0 | 2045.3 ± 69.8 | 2182.1 ± 53.6 | 2157.2 ± 53.1 | 0.04 |
| HEI-2015 | 51.4 ± 1.52 | 49.5 ± 1.16 | 48.8 ± 1.12 | 50.6 ± 0.91 | 0.02 |
| BMI (kg/m2) | |||||
| < 25.0 | 30.2 (4.1) | 25.0 (4.1) | 18.4 (2.4) | 22.3 (3.1) | 0.17 |
| 25–29.9 | 31.0 (3.9) | 30.4 (2.8) | 34.4 (3.3) | 27.0 (3.3) | |
| ≥ 30.0 | 38.7 (3.6) | 44.7 (4.5) | 47.2 (3.3) | 50.7 (4.4) | |
| Family history of diabetes | |||||
| Yes | 49.7 (2.6) | 45.9 (4.4) | 44.2 (3.2) | 40.2 (4.3) | 0.28 |
| No | 50.3 (2.6) | 54.1 (4.4) | 55.8 (3.2) | 59.8 (4.3) | |
| Blood cadmium (μg/L) | 0.44 ± 0.04 | 0.43 ± 0.03 | 0.39 ± 0.04 | 0.54 ± 0.05 | 0.005 |
| Blood lead (μg/dL) | 1.02 ± 0.04 | 1.08 ± 0.06 | 1.22 ± 0.07 | 1.22 ± 0.07 | 0.003 |
| Diabetes | |||||
| Yes | 9.1 (2.0) | 14.6 (2.5) | 18.4 (2.6) | 15.6 (2.2) | 0.04 |
| No | 90.9 (2.0) | 85.4 (2.5) | 81.6 (2.6) | 84.4 (2.2) | |
Unless indicated otherwise, data are given as the weighted mean ± SEM for continuous variables and weighted percentages (SEs) for categorical variables
BMI body mass index, HEI-2015 2015 healthy eating index, MET metabolic equivalent of task, PIR family income-to-poverty ratio