Table 4.
ORs (95% CI) for MetS according to the quartiles of dietary iron, zinc and magnesium intakes (mg/day) in 5323 participants from CNHS and SDHS, stratified by food sources 1, 2.
| Quartiles of Dietary Iron, Zinc or Magnesium (mg/day), ORs (95% CI) | |||||||
|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | p-Value for Trend | |||
| n | 1330 | 1331 | 1331 | 1331 | |||
| Dietary Source of Red Meat | |||||||
| Iron | |||||||
| < 0.35 | (0.35, 0.91) | (0.91, 1.65) | ≥ 1.65 | ||||
| Model 1 | Reference | 0.80(0.69, 0.93) | 0.76(0.65, 0.89) | 0.65(0.56, 0.76) | < 0.01 | ||
| Model 2 | Reference | 0.79(0.67, 0.93) | 0.81(0.68, 0.96) | 0.74(0.62, 0.88) | < 0.01 | ||
| Model 3 | Reference | 0.81(0.53, 1.25) | 0.96(0.58, 1.60) | 1.03(0.59, 1.82) | 0.47 | ||
| Zinc | |||||||
| < 0.45 | (0.45, 1.18) | (1.18, 2.21) | ≥ 2.21 | ||||
| Model 1 | Reference | 0.85(0.73, 0.99) | 0.73(0.62, 0.85) | 0.65(0.56, 0.76) | < 0.01 | ||
| Model 2 | Reference | 0.84(0.72, 0.99) | 0.77(0.65, 0.91) | 0.74(0.62, 0.88) | < 0.01 | ||
| Model 3 | Reference | 0.97(0.59, 1.60) | 0.70(0.39, 1.26) | 0.71(0.38, 1.34) | 0.21 | ||
| Magnesium | |||||||
| < 3.33 | (3.33, 8.53) | (8.53, 15.60) | ≥ 15.60 | ||||
| Model 1 | Reference | 0.79(0.68, 0.93) | 0.83(0.71, 0.96) | 0.62(0.53, 0.72) | < 0.01 | ||
| Model 2 | Reference | 0.81(0.68, 0.95) | 0.85(0.72, 1.00) | 0.71(0.60, 0.85) | < 0.01 | ||
| Model 3 | Reference | 1.01(0.64, 1.59) | 1.20(0.71, 2.03) | 0.97(0.54, 1.74) | 0.29 | ||
| Dietary Source of Grain and Potato | |||||||
| Iron | |||||||
| < 4.45 | (4.45, 6.14) | (6.14, 8.26) | ≥ 8.26 | ||||
| Model 1 | Reference | 1.25(1.06, 1.47) | 1.52(1.29, 1.78) | 1.63(1.39, 1.92) | < 0.01 | ||
| Model 2 | Reference | 1.32(1.11, 1.57) | 1.72(1.44, 2.05) | 2.08(1.71, 2.53) | < 0.01 | ||
| Model 3 | Reference | 1.04(0.82, 1.32) | 1.09(0.81, 1.46) | 1.19(0.84, 1.67) | 0.77 | ||
| Zinc | |||||||
| < 2.55 | (2.55, 3.38) | (3.38, 4.49) | ≥ 4.49 | ||||
| Model 1 | Reference | 1.11(0.95, 1.31) | 1.32(1.13, 1.55) | 1.27(1.08, 1.48) | < 0.01 | ||
| Model 2 | Reference | 1.14(0.96, 1.35) | 1.45(1.21, 1.72) | 1.63(1.34, 2.00) | < 0.01 | ||
| Model 3 | Reference | 0.74(0.60, 0.92) | 0.68(0.52, 0.88) | 0.59(0.43, 0.81) | 0.01 | ||
| Magnesium | |||||||
| < 62.55 | (62.55, 89.87) | (89.87, 125.86) | ≥ 125.86 | ||||
| Model 1 | Reference | 1.37(1.16, 1.61) | 1.78(1.51, 2.10) | 2.02(1.71, 2.37) | < 0.01 | ||
| Model 2 | Reference | 1.46(1.22, 1.74) | 2.08(1.74, 2.48) | 2.60(2.14, 3.16) | < 0.01 | ||
| Model 3 | Reference | 1.69(1.35, 2.13) | 2.57(1.95, 3.39) | 3.26(2.36, 4.50) | < 0.01 | ||
| Dietary Source of Vegetables and Fruit | |||||||
| Iron | |||||||
| < 2.15 | (2.15, 3.54) | (3.54, 5.51) | ≥ 5.51 | ||||
| Model 1 | Reference | 0.86(0.74, 1.01) | 0.89(0.76, 1.04) | 0.81(0.69, 0.95) | 0.07 | ||
| Model 2 | Reference | 0.83(0.67, 1.03) | 0.76(0.61, 0.95) | 0.69(0.55, 0.87) | 0.01 | ||
| Model 3 | Reference | 0.93(0.67, 1.30) | 0.88(0.59, 1.32) | 0.77(0.48, 1.24) | 0.72 | ||
| Zinc | |||||||
| < 0.82 | (0.82, 1.38) | (1.38, 2.36) | ≥ 2.36 | ||||
| Model 1 | Reference | 1.03(0.88, 1.20) | 0.97(0.83, 1.14) | 0.82(0.70, 0.96) | 0.07 | ||
| Model 2 | Reference | 0.94(0.80, 1.11) | 0.90(0.76, 1.07) | 0.68(0.57, 0.81) | < 0.01 | ||
| Model 3 | Reference | 1.06(0.78, 1.43) | 1.16(0.78, 1.72) | 1.03(0.62, 1.69) | 0.78 | ||
| Magnesium | |||||||
| < 38.60 | (38.60, 63.36) | (63.36, 101.58) | ≥ 101.58 | ||||
| Model 1 | Reference | 1.02(0.87, 1.19) | 0.95(0.81, 1.11) | 0.96(0.82, 1.12) | 0.76 | ||
| Model 2 | Reference | 0.92(0.78, 1.08) | 0.83(0.70, 0.98) | 0.76(0.63, 0.90) | 0.01 | ||
| Model 3 | Reference | 0.80(0.58, 1.09) | 0.71(0.48, 1.05) | 0.86(0.54, 1.36) | 0.24 | ||
1 Model 1 was a crude model which included no covariate. Model 2 was adjusted for age, sex, region, years of education, physical activity level, intended physical exercises, smoking status, alcohol use and daily energy intake, which included the variables mentioned ahead as covariates in the regression models. Model 3 was adjusted for the covariates in Model 2 and additionally mutually adjusted for iron, zinc and magnesium (e.g., when focusing on the relationship between dietary iron and MetS risk, dietary zinc and magnesium were included in the regression models), which included the variables mentioned above as covariates in the regression models. 2 Hierarchical logistic regression models were applied to identify the trends between dietary iron, zinc or magnesium intakes and MetS risk. The levels (1, 2, 3 and 4) of the dietary intake quartiles and other covariates mentioned above were as the independent variables and the occurrence of MetS as the dependent variable in the regression models.