Table 1.
Baseline demographic, clinical characteristics of the study population and study outcomes, stratified by tertiles of serum Prx4 levels.
| Total | T1 | T2 | T3 | P-value | |
|---|---|---|---|---|---|
| <0.50 U/L | 0.50–0.87 U/L | >0.87 U/L | |||
| n=1781 | n=1780 | n=1780 | |||
| Prx4 (U/L) | 0.65 [0.42–1.04] | 0.37 [0.37–0.42] | 0.65 [0.57–0.75] | 1.30 [1.04–1.81] | <0.001 |
| Prx4 (U/L) (Females) | 0.64 [0.41–1.01] | 0.37 [0.37–0.42] | 0.65 [0.57–0.74] | 1.29 [1.03–1.78] | <0.001 |
| Prx4 (U/L) (Males) | 0.67 [0.43–1.07] | 0.37 [0.37–0.42] | 0.66 [0.57–0.75] | 1.32 [1.04–1.84] | <0.001 |
| Demographics | |||||
| Age (years) | 47.0 [38.8–56.4] | 45.6 [37.7–53.8] | 47.2 [38.7–55.9] | 48.3 [40.2–60.2] | <0.001 |
| Female, n (%) | 2820 (53) | 969 (54) | 945 (53) | 906 (51) | 0.106 |
| Race, n (%) | <0.001 | ||||
| Asian, n (%) | 104 (2) | 16 (0.9) | 29 (2) | 59 (3) | |
| Black, n (%) | 53 (10) | 6 (0.3) | 15 (0.8) | 32 (2) | |
| Other, n (%) | 61 (1) | 21 (1) | 19 (1) | 21 (1) | |
| White, n (%) | 5086 (96) | 1723 (98) | 1707 (96) | 1656 (94) | |
| Anthropometrics | |||||
| BMI (kg/m2) | 25.2 [23.0–27.8] | 24.6 [22.6–27.0] | 25.3 [22.9–27.8] | 25.8 [23.3–28.7] | <0.001 |
| Waist circumference (cm) | 86.5 [77.5–95.0] | 84.5 [77.0–92.5] | 86.5 [77.0–95.0] | 89.0 [80.0–98.0] | <0.001 |
| Risk factors | |||||
| SBP (mmHg) | 123 [112–136] | 121 [111–133] | 123 [113–136] | 126 [114–140] | <0.001 |
| DBP (mmHg) | 72 [66–79] | 71 [65–77] | 72 [66–79] | 74 [68–80] | <0.001 |
| Heart rate (bpm) | 68 [62–75] | 68 [61–74] | 68 [62–74] | 69 [63–76] | <0.001 |
| Smoking | <0.001 | ||||
| Never, n (%) | 1691 (32) | 523 (30) | 587 (33) | 581 (33) | |
| Current, n (%) | 1687 (32) | 662 (37) | 541 (31) | 491 (28) | |
| Former (<1 year), n (%) | 200 (4) | 79 (5) | 58 (3) | 63 (4) | |
| Former (>1 year), n (%) | 1735 (33) | 511 (29) | 585 (33) | 639 (36) | |
| History of CHF, n (%) | 146 (3) | 23 (1) | 46 (3) | 77 (4) | <0.001 |
| History of diabetes, n (%) | 77 (1) | 10 (0.6) | 25 (1) | 42 (2) | <0.001 |
| Medication use | |||||
| Antihypertensive drugs, n (%) | 532 (12) | 122 (9) | 174 (12) | 236 (16) | <0.001 |
| Lipid-lowering drugs, n (%) | 162 (4) | 46 (3) | 46 (3) | 70 (5) | 0.055 |
| Antidiabetic drugs, n (%) | 50 (0.9) | 9 (0.5) | 15 (0.9) | 26 (2) | 0.010 |
| Laboratory measurements | |||||
| Total cholesterol (mmol/L) | 5.50 [4.80–6.30] | 5.50 [4.80–6.30] | 5.40 [4.76–6.20] | 5.55 [4.80–6.30] | 0.019 |
| hs-CRP (mg/L) | 1.07 [0.49–2.56] | 0.84 [0.39–1.84] | 1.05 [0.48–2.45] | 1.42 [0.63–3.38] | <0.001 |
| Cystatin C (mg/L) | 0.86 [0.77–0.95] | 0.85 [0.76–0.93] | 0.85 [0.77–0.94] | 0.88 [0.79–0.98] | <0.001 |
| Creatinine (mmol/L) | 69.6 [61.0–79.3] | 69.6 [61.0–79.3] | 69.6 [61.0–79.3] | 69.6 [61.0–78.3] | 0.866 |
| eGFR (mL/min/1.73 m2) | 98 [87–108] | 100 [89–109] | 98 [88–103] | 96 [84–107] | <0.001 |
| UAE (mg/L) | 8.1 [6.0–12.1] | 7.9 [5.8–11.4] | 8.1 [6.0–12.0] | 8.4 [6.1–13.0] | 0.001 |
| Urine creatinine (mmol/24-h) | 8.2 [6.0–11.1] | 8.1 [5.9–10.9] | 8.2 [6.0–11.2] | 8.2 [6.1–11.1] | 0.428 |
| Urine urea (mmol/24-h) | 223 [165–308] | 223 [165–307] | 225 [162–309] | 224 [166–310] | 0.866 |
| Study outcomes | |||||
| CKD (eGFR <60 mL/min/1.73 m2), n (%) | 289 (5) | 65 (4) | 86 (5) | 138 (8) | <0.001 |
| CKD (UAE >30 mg/24-h), n (%) | 667 (13) | 166 (9) | 199 (11) | 302 (17) | <0.001 |
| CKD (combination), n (%) | 867 (16) | 218 (12) | 257 (14) | 389 (22) | <0.001 |
Data are presented as median [interquartile range] or n (%). Abbreviations: Prx4, peroxiredoxin 4; U/L, units per liter; T1, tertile 1; T2, tertile 2; T3, tertile 3; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; bpm, beats per minute; CHF, congestive heart failure; hs-CRP, high-sensitivity C-reactive protein; eGFR, estimated glomerular filtration rate; UAE, urinaryalbumin excretion; CKD, chronic kidney disease.