Table 3.
Multiple logistic regression between UIC and MetS and its components.
| Variables | N (%) | Crude model | Model 1 | Model 2 | Model 3 | ||||
|---|---|---|---|---|---|---|---|---|---|
| OR (95%CI) | p | OR (95%CI) | p | OR (95%CI) | p | OR (95%CI) | p | ||
| MetS | |||||||||
| UIC (log10) | 1.69(1.441,1.982) | <0.001* | 1.54(1.301,1.816) | <0.001* | 1.50(1.272,1.757) | <0.001* | 1.50(1.275,1.756) | <0.001* | |
| Classified UIC | |||||||||
| normal UIC | 1627(48.23) | ref | ref | ref | ref | ||||
| low UIC | 962(31.68) | 0.77(0.665,0.891) | <0.001* | 0.81(0.699,0.941) | 0.006* | 0.82(0.706,0.949) | 0.009* | 0.82(0.708,0.946) | 0.007* |
| high UIC | 262(9.48) | 1.31(1.069,1.600) | 0.01* | 1.26(1.018,1.547) | 0.033* | 1.26(1.020,1.555) | 0.033* | 1.25(1.016,1.539) | 0.035* |
| very high UIC | 349(10.61) | 1.13(0.933,1.358) | 0.213 | 1.08(0.888,1.314) | 0.435 | 1.04(0.858,1.263) | 0.681 | 1.05(0.862,1.270) | 0.644 |
| p for trend | 0.222 | 0.39 | 0.531 | 0.515 | |||||
| MetS.Diabetes | |||||||||
| normal UIC | 1831(49.24) | ref | ref | ref | ref | ||||
| low UIC | 1129(33.61) | 0.80(0.704,0.916) | 0.001* | 0.90(0.791,1.026) | 0.114 | 0.91(0.798,1.032) | 0.138 | 0.90(0.791,1.022) | 0.103 |
| high UIC | 285(8.86) | 1.16(0.909,1.470) | 0.234 | 1.06(0.814,1.382) | 0.659 | 1.08(0.828,1.407) | 0.57 | 1.08(0.830,1.407) | 0.560 |
| very high UIC | 305(8.28) | 0.78(0.622,0.972) | 0.027* | 0.70(0.555,0.869) | 0.002* | 0.69(0.549,0.860) | 0.001* | 0.68(0.542,0.855) | 0.001* |
| p for trend | 0.063 | 0.009* | 0.01* | 0.008* | |||||
| MetS.obesity | |||||||||
| normal UIC | 3265(47.12) | ref | ref | ref | ref | ||||
| low UIC | 2189(34.93) | 0.84(0.749,0.946) | 0.004* | 0.84(0.742,0.947) | 0.005* | 0.85(0.749,0.954) | 0.007* | 0.83(0.731,0.945) | 0.005* |
| high UIC | 502(8.03) | 1.12(0.919,1.357) | 0.262 | 1.08(0.881,1.329) | 0.448 | 1.09(0.879,1.356) | 0.422 | 1.11(0.885,1.390) | 0.364 |
| very high UIC | 691(9.92) | 1.11(0.933,1.309) | 0.246 | 1.08(0.910,1.281) | 0.376 | 1.05(0.879,1.252) | 0.592 | 1.01(0.837,1.204) | 0.970 |
| p for trend | 0.454 | 0.693 | 0.852 | 0.856 | |||||
| MetS.hypertension | |||||||||
| normal UIC | 964(46.18) | ref | ref | ref | ref | ||||
| low UIC | 707(37.13) | 1.01(0.857,1.180) | 0.947 | 1.12(0.952,1.319) | 0.169 | 1.12(0.948,1.322) | 0.181 | 1.13(0.953,1.329) | 0.162 |
| high UIC | 149(7.61) | 1.01(0.782,1.315) | 0.915 | 0.94(0.718,1.224) | 0.631 | 0.96(0.731,1.252) | 0.746 | 0.95(0.726,1.237) | 0.688 |
| very high UIC | 203(9.08) | 0.97(0.775,1.211) | 0.775 | 0.90(0.706,1.135) | 0.357 | 0.91(0.719,1.154) | 0.435 | 0.92(0.725,1.166) | 0.481 |
| p for trend | 0.876 | 0.532 | 0.654 | 0.683 | |||||
| MetS.low-HDL-C | |||||||||
| normal UIC | 1741(47.09) | ref | ref | ref | ref | ||||
| low UIC | 1151(33.23) | 0.84(0.758,0.928) | <0.001* | 0.80(0.723,0.887) | <0.001* | 0.81(0.729,0.895) | <0.001* | 0.81(0.732,0.894) | <0.001* |
| high UIC | 293(9.00) | 1.27(1.020,1.578) | 0.033* | 1.31(1.041,1.636) | 0.021* | 1.31(1.046,1.634) | 0.019* | 1.30(1.043,1.630) | 0.020* |
| very high UIC | 386(10.68) | 1.19(1.002,1.401) | 0.047* | 1.22(1.030,1.436) | 0.021* | 1.17(0.990,1.392) | 0.065 | 1.18(0.985,1.410) | 0.072 |
| p for trend | 0.049* | 0.033* | 0.061 | 0.064 | |||||
| MetS.TG | |||||||||
| normal UIC | 2103(47.30) | ref | ref | ref | ref | ||||
| low UIC | 1298(32.31) | 0.79(0.691,0.893) | <0.001* | 0.84(0.739,0.960) | 0.011* | 0.84(0.738,0.959) | 0.011* | 0.85(0.746,0.965) | 0.013* |
| high UIC | 350(9.05) | 1.31(1.069,1.604) | 0.01* | 1.25(1.016,1.547) | 0.035* | 1.25(1.013,1.537) | 0.038* | 1.24(1.002,1.533) | 0.048* |
| very high UIC | 497(11.35) | 1.33(1.137,1.565) | <0.001* | 1.28(1.083,1.522) | 0.004* | 1.26(1.068,1.492) | 0.007* | 1.26(1.082,1.503) | 0.004* |
| p for trend | 0.006* | 0.018* | 0.024* | 0.018* | |||||
UIC, urinary iodine concentration; MetS, metabolic syndromes; HDL, high-density lipoprotein; TG, triglyceride.
MetS.Diabetes, History of diabetes, Glycosylated hemoglobin (HbA1c) > 6.5%, fasting glucose (mmol/L) ≥ 7.0, or medication used to treat diabetes;
MetS.obesity, Waist Circumference (WC) ≥ 102 cm in men or ≥ 88 cm in women;
MetS.hypertension, blood pressure ≥ 130/85 mmHg or hypertension history or treatment with antihypertensive medication;
MetS.low-HDL-C, HDL-C < 40 mg/dL for men and < 50 mg/dL for women or use of anti-lipid abnormalities;
MetS.TG, TG ≥ 150 mg/dL or pharmacological treatment of TG.
Data are expressed as weighted percentages. OR and 95% CI for risk of metabolic syndrome and its components were estimated using complex samples logistic regression. * represents p < 0.05.
Normal UIC: < 100ug/L; Low UIC: 100-299ug/L; High UIC: 300-399ug/L; Very high UIC: ≥ 400ug/L.
Crude Model: not adjusted;
Model 1: Adjusted for age, sex;
Model 2: Adjusted for age, sex, race/ethnicity, education, the annual family income, smoking status, alcohol intake, physical activity,
Model 3: Adjusted for age, sex, race/ethnicity, education, the annual family income, smoking status, alcohol intake, physical activity, thyroid problems, cancer, energy intake, fish or shellfish intake, sodium intake, eGFR, TSH, and FT4.