Table 1.
Characteristics of the Study Cohort at Baseline by Quartiles of Urinary Cadmium
| Variable, mean (range) unless otherwise specified | All | Quartiles of urinary cadmium | p Value a | |||
|---|---|---|---|---|---|---|
| (N = 936) | Q1 (n = 229) | Q2 (n = 238) | Q3 (n = 230) | Q4 (n = 239) | ||
| Cadmium in urine (μg/g creatinine) | 0.33 (0.01–6.98) | 0.14 (0.01–0.17) | 0.21 (0.18–0.25) | 0.31 (0.26–0.36) | 0.67 (0.37–6.98) | |
| Age (years) | 75.3 (70.5–81.0) | 75.2 (70.5–80.9) | 75.5 (70.5–81.0) | 75.4 (70.5–81.0) | 75.0 (70.5–80.9) | 0.278 |
| Body weight (kg) | 81.2 (48.1–138.3) | 82.5 (60.6–138.3) | 80.9 (57.5–127.4) | 82.1 (54.2–114.5) | 79.2 (48.1–126.6) | 0.015 |
| Body height (cm) | 175.8 (155.0–199.4) | 175.9 (156.8–194.0) | 175.6 (155.0–194.2) | 176.6 (158.8–199.0) | 174.9 (158.6–199.4) | 0.038 |
| BMI (kg/m2) | 26.3 (16.3–43.7) | 26.6 (18.5–43.7) | 26.2 (18.8–42.2) | 26.3 (17.9–37.2) | 25.9 (16.3–39.3) | 0.118 |
| Total body fat mass (kg) | 18.6 (4.5–38.2) | 18.6 (7.7–34.5) | 18.9 (6.3–35.0) | 18.8 (4.5–38.2) | 18.0 (5.7–37.1) | 0.352 |
| Total body lean mass (kg) | 59.3 (41.8–81.3) | 60.4 (42.4–79.6) | 59.2 (42.6–78.7) | 60.2 (46.3–78.3) | 57.7 (41.8–81.3) | <0.001 |
| Smoking status, N | 910 | <0.001 | ||||
| Never‐smoker, n (%) | 353 (39) | 144 (64.3) | 114 (49.1) | 76 (33.9) | 19 (8.3) | |
| Former smoker, n (%) | 484 (53) | 79 (35.3) | 115 (49.6) | 135 (60.3) | 155 (67.4) | |
| Current smoker, n (%) | 73 (8) | 1 (0.45) | 3 (1.3) | 13 (5.8) | 56 (24.3) | |
| Pack‐years (never/former/current smokers) | 13.4 (0–93.0) | 4.2 (0–70.5) | 7.2 (0–67.5) | 14.0 (0–93.0) | 28.4 (0–84.0) | <0.001 |
| Medication with corticosteroids, n (%) | 13 (1) | 0 (0) | 5 (2.1) | 2 (0.87) | 6 (2.5) | 0.054 |
| Medication against osteoporosis, n (%) | 5 (0.5) | 0 (0) | 1 (0.42) | 1 (0.43) | 3 (1.3) | 0.412 |
| Physical activity (km/d) | 4.0 (0–22.0) | 3.8 (0–14.0) | 4.1 (0–16.0) | 4.1 (0–17.0) | 3.9 (0–22.0) | 0.651 |
| Falls during the last year, n (%) | 140/907 (15) | 25/222 (11) | 39/233 (17) | 29/223 (13) | 47/229 (21) | 0.032 |
| Calcium intake (mg/d) | 929 (60.7–4140) | 945 (224–2236) | 917 (148–2919) | 902 (60.7–2562) | 952 (82.5–4140) | 0.527 |
| Diabetes (anamnestic/B‐glucose >7), n (%) | 139 (15) | 44 (19.7) | 36 (15.9) | 31 (14.0) | 28 (12.3) | 0.152 |
| Intact parathyroid hormone (pM) | 6.0 (1.3–71.8) | 6.3 (1.3–68.8) | 5.8 (2.1–19.9) | 6.2 (1.9–71.8) | 5.8 (1.9–16.2) | 0.404 |
| 25(OH)‐vitamin D (nM) | 66.7 (12.0–148) | 66.7 (22.0–146) | 66.8 (22.0–129) | 66.1 (15.0–118) | 67.2 (12.0–148) | 0.944 |
| eGFR (mL/min/1.73 m2) | 71.3 (18.0–288) | 71.0 (18.0–121) | 73.0 (29.0–288) | 71.1 (31.0–142) | 70.2 (22.0–133) | 0.457 |
| Total testosterone (nM) | 15.5 (0.09–43.9) | 15.3 (0.24–43.9) | 15.6 (0.09–36.4) | 15.7 (0.09–37.3) | 15.2 (0.09–37.1) | 0.837 |
| Free testosterone (nM) | 0.26 (0.001–1.04) | 0.26 (0.004–1.0) | 0.26 (0.001–0.64) | 0.27 (0.001–0.72) | 0.26 (0.001–0.66) | 0.989 |
| Total estradiol (pM) | 77.3 (3.7–202.6) | 79.7 (3.7–202.6) | 77.4 (3.7–202.6) | 77.3 (3.7–177.7) | 74.8 (3.7–202.6) | 0.399 |
| Free estradiol (pM) | 1.3 (0.03–3.7) | 1.3 (0.06–3.2) | 1.3 (0.04–3.5) | 1.3 (0.05–3.6) | 1.3 (0.03–3.7) | 0.572 |
| SHBG (nM) | 47.3 (3.3–269.5) | 47.0 (3.3–269.5) | 47.2 (3.6–126.7) | 47.4 (12.8–164.1) | 47.5 (11.9–170.0) | 0.997 |
| PINP (ng/mL) | 40.8 (4.0–191.3) | 41.7 (4.0–183.5) | 39.7 (11.0–171.6) | 40.8 (15.4–191.3) | 41.0 (12.5–94.3) | 0.727 |
| Osteocalcin (μg/L) | 26.8 (8.0–280.0) | 27.9 (8.0–280.0) | 26.4 (8.0–88.0) | 26.3 (10.0–78.0) | 26.5 (9.0–60.0) | 0.524 |
| BMD | ||||||
| Total body BMD (g/cm2) | 1.09 (0.77–1.59) | 1.12 (0.86–1.45) | 1.10 (0.77–1.59) | 1.09 (0.79–1.44) | 1.07 (0.83–1.35) | <0.001 |
| Total hip, sBMD, right‐left (g/cm2) | 0.96 (0.59–1.65) | 1.00 (0.64–1.55) | 0.97 (0.62–1.45) | 0.96 (0.59–1.53) | 0.93 (0.63–1.65) | <0.001 |
| Femoral neck, sBMD, right‐left (g/cm2) | 0.85 (0.54–1.50) | 0.87 (0.58–1.48) | 0.86 (0.57–1.38) | 0.85 (0.54–1.50) | 0.82 (0.58–1.35) | 0.002 |
| Trochanter, sBMD, right‐left (g/cm2) | 0.82 (0.49–1.43) | 0.85 (0.53–1.38) | 0.83 (0.51–1.43) | 0.81 (0.51–1.37) | 0.78 (0.49–1.39) | <0.001 |
| Lumbar spine L1 to L4, sBMD (g/cm2) | 1.12 (0.61–1.95) | 1.15 (0.73–1.87) | 1.12 (0.72–1.95) | 1.11 (0.61–1.73) | 1.10 (0.62–1.73) | 0.015 |
eGFR = glomerular filtration rate estimated from cystatin C; SHBG = sex hormone–binding globulin; PINP = N‐terminal propeptide of type I procollagen; sBMD = standardized BMD.
a
ANOVA, chi‐square, or Fisher's exact test.