Table 2. Baseline characteristics of the participants by sex-specific quartiles of serum ferritin.
| Men (3522) | P for trenda | Women (3587) | P for trenda | P valueb | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | Q1 | Q2 | Q3 | Q4 | ||||
| Ferritin, mg/L | 56.42 (23.92) | 100.06 (22.14) | 154.27 (39.58) | 379.90 (323.36) | <0.001 | 24.52 (9.39) | 47.12 (12.39) | 77.99 (20.83) | 156.40 (109.31) | <0.001 | <0.001 |
| Age, years | 51.43+15.52 | 49.81+15.21 | 49.67+14.80 | 49.02+13.66 | 0.002 | 40.78+11.60 | 47.12+14.35 | 54.12+13.65 | 60.22+11.32 | <0.001 | 0.682 |
| BMI, kg/m2 | 22.63+3.28 | 23.07+3.35 | 23.52+3.30 | 24.38+3.42 | <0.001 | 23.06(3.50) | 23.29(3.39) | 23.82(3.57) | 24.41(3.63) | <0.001 | 0.005 |
| SBP, mm Hg | 126.27+18.41 | 125.70+17.84 | 125.37+16.61 | 126.43+16.78 | 0.432 | 117.11+16.72 | 120.88+18.39 | 126.18+19.92 | 131.54+22.01 | <0.001 | <0.001 |
| DBP, mm Hg | 81.63+11.03 | 81.84+11.01 | 82.12+11.11 | 83.70+11.04 | <0.001 | 77.23+10.76 | 78.32+10.70 | 80.90+11.42 | 83.03+12.12 | <0.001 | 0.029 |
| TC, mmol/L | 4.62(1.24) | 4.60(1.13) | 4.79(1.17) | 4.97(1.38) | <0.001 | 4.53(1.11) | 4.70(1.24) | 5.06(1.40) | 5.26(1.32) | <0.001 | <0.001 |
| TG, mmol/L | 1.06(0.75) | 1.21(0.86) | 1.34(1.11) | 1.64(1.38) | <0.001 | 1.00(0.69) | 1.13(0.82) | 1.27(0.91) | 1.57(1.19) | <0.001 | 0.004 |
| HDL-C, mmol/L | 1.38(0.45) | 1.33(0.48) | 1.29(0.46) | 1.23(0.47) | <0.001 | 1.47(0.44) | 1.44(0.44) | 1.44(0.47) | 1.38(0.45) | <0.001 | <0.001 |
| LDL-C, mmol/L | 2.80(1.16) | 2.85(1.02) | 2.94(1.17) | 2.98(1.36) | 0.009 | 2.74(0.99) | 2.88(1.18) | 3.20(1.30) | 3.28(1.40) | <0.001 | <0.001 |
| FPG, mmol/L | 5.00(0.89) | 5.04(0.94) | 5.10(0.93) | 5.20(1.09) | <0.001 | 4.96(0.72) | 5.03(0.84) | 5.10(0.95) | 5.24(1.08) | <0.001 | 0.821 |
| HbA1c, % | 5.50(0.60) | 5.50(0.60) | 5.50(0.60) | 5.60(0.60) | <0.001 | 5.40(0.50) | 5.50(0.70) | 5.50(0.60) | 5.70(0.70) | <0.001 | 0.464 |
| Insulin, μIU/mL | 9.50(6.87) | 10.19(7.43) | 10.79(8.26) | 11.50(9.57) | <0.001 | 10.08(7.19) | 10.28(7.40) | 11.02(7.14) | 12.16(9.00) | <0.001 | 0.080 |
| HOMA-IR | 2.14(1.76) | 2.31(1.87) | 2.44(2.19) | 2.68(2.84) | <0.001 | 2.22(1.67) | 2.28(1.82) | 2.49(1.93) | 2.92(2.54) | <0.001 | 0.122 |
| Hemoglobin, g/L | 153.20+14.88 | 154.93+14.20 | 155.98+14.75 | 157.28+14.05 | <0.001 | 136.52+14.49 | 137.63+14.03 | 138.46+15.08 | 138.36+14.39 | <0.001 | |
| Smokers, % | 59.82 | 61.48 | 63.90 | 63.98 | 0.071 | 2.34 | 4.01 | 4.79 | 5.92 | 0.002 | <0.001 |
| Alcohol use/last year, % | 55.96 | 58.75 | 65.61 | 63.75 | <0.001 | 7.36 | 9.70 | 9.81 | 7.70 | 0.127 | <0.001 |
| Education, % | <0.001 | <0.001 | <0.001 | ||||||||
| Low | 36.89 | 31.25 | 33.83 | 28.98 | 35.23 | 43.59 | 56.41 | 69.31 | |||
| Medium | 39.61 | 38.86 | 36.78 | 40.34 | 41.92 | 31.77 | 23.86 | 17.97 | |||
| High | 23.50 | 29.89 | 29.40 | 30.68 | 22.85 | 24.64 | 19.73 | 12.72 | |||
| Daily carbohydrate intake, g | 316.32(149.92) | 316.07(146.07) | 315.96(135.11) | 306.14(131.55) | 0.190 | 266.53(116.46) | 262.46(119.93) | 260.25(118.52) | 252.86(103.38) | 0.007 | <0.001 |
| Daily fat intake, g | 72.51(46.82) | 74.46(44.87) | 73.46(45.42) | 76.83(47.98) | 0.241 | 64.80(40.66) | 64.22(39.30) | 65.02(42.23) | 64.59(45.90) | 0.498 | <0.001 |
| Daily energy intake, kcal | 2249.02(861.21) | 2320.85(834.65) | 2311.53(849.69) | 2293.11(870.14) | 0.476 | 1947.47(755.94) | 1940.57(726.48) | 1945.15(749.25) | 1843.30(682.65) | 0.029 | <0.001 |
| Daily protein intake, g | 66.25(31.44) | 68.16(29.80) | 69.82(31.11) | 70.90(30.61) | 0.007 | 59.18(27.31) | 58.87(24.87) | 58.37(26.89) | 57.26(25.55) | 0.126 | <0.001 |
Values are presented as the mean±SD or median (interquartile range) or percent
BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; TC, total cholesterol; TG, triglycerides; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin A1c; HOMA-IR, homeostatic model assessment of insulin resistance.
a P for trend across quartiles of serum ferritin within gender group.
b P for difference of both gender groups.