Table 2.
Association between heavy metal exposure with risk of metabolic syndrome according to type of exposure and outcome
| Author, Year | Type of metal | Unit of exposure (categorical/continues) | Outcome | Unit of outcome(categorical/continues) | Definition of outcome | Statistical measure (SE) | Results | Significant association | Country |
|---|---|---|---|---|---|---|---|---|---|
| Lead (pb) | |||||||||
| Rotter et al.2015 |
lead (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on criteria of IDF | OR(95% CI) | 1.12(0.75,1.68) | No | Poland |
| Rhee et al. 2013 |
lead (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 2.57 (1.46,4.51) | Yes | South Korea |
| Park et al. 2020 |
lead (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) |
Male:0.97(0.38,2.45) Female: 0.04(0.001,1.67) |
No | Republic of Korea |
| Moon et al.2014 |
lead (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.07(0.79,1.5) | Yes | South Korea |
| Lee et al. 2012 |
lead (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.97(0.819,1.141) | No | South Korea |
| Lee et al. 2017 |
lead (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.37(1.02,1.84) | Yes | South Korea |
| Lee et al. 2016 |
lead (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.80 (0.60,1.049) | No | South Korea |
| Jin et al. 2013 |
lead (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.61(1.15,2.24) | Yes | China |
| Guo et al. 2019 |
lead (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.81(0.83,3.92) | No | China |
| Duc et al. 2021 |
lead (μg/dL) |
Continues | MetS | Categorical | American Heart Association/National Heart, Lung, and Blood Institute for clinical diagnosis | OR(95% CI) | 1.14(1.03,1.26) | Yes | Korea |
| Bulka et al. 2019 |
lead (μg/dL) |
Categorical(q3/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS |
OR(95% CI) | 0.82 (0.54, 1.04) | No | USA |
| Kaminska et al. 2020 |
lead (μg/dL) |
Continues | MetS | Categorical |
American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI), 2009 |
OR(95% CI) | 0.33(0.17,0.60) | Yes | Poland |
| Park et al. 2018 |
lead (μg/dL) |
Categorical(q4/q1) | MetS | Categorical |
The definition of MetS using abdominal obesity diagnostic criteria published by the Korean Society for the Study of Obesity (KSSO) |
OR(95% CI) |
Male: 1.17(1.01,1.36) Female: 1.09(0.93,1.29) |
Male: Yes Female: No |
Korea |
| Shim et al. 2019 |
lead (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.86(0.65,1.14) | No | South Korea |
| Wen et al. 2020 |
lead (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.86(0.61,1.2) | No | Taiwan |
| Mercury | |||||||||
| Rotter et al. 2015 |
Mercury (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on IDF | OR(95% CI) | 1.18(0.79,1.77) | No | Poland |
| Rhee et al. 2013 |
Mercury (μg/dL) |
Categorical(q4/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.19 (0.76–1.87) | No | South Korea |
| Park et al. 2020 |
Mercury (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) |
Male:0.79(0.53,1.18) Female: 0.73(0.34,1.58) |
No | Republic of Korea |
| Moon et al. 2014 |
Mercury (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.13(0.86,1.49) | No | South Korea |
| Lee et al. 2012 |
Mercury (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.994(0.870,1.136) | No | South Korea |
| Lee et al. 2017 |
Mercury (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.43 (1.05,1.94) | Yes | South Korea |
| Lee et al. 2016 |
Mercury (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.96 (0.79,1.16) | No | South Korea |
| Duc et al. 2021 |
Mercury (μg/dL) |
Continues | MetS | Categorical | American Heart Association/National Heart, Lung, and Blood Institute for clinical diagnosis | OR(95% CI) | 1.03(1.02,1.06) | Yes | Korea |
| Bulka et al. 2019 | methylmercury (µg/dL) | Categorical(q3/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS |
OR(95% CI) | 1.10 (0.91–1.33) | No | USA |
| Shim et al. 2019 |
Mercury (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.99(0.73,1.34) | No | South Korea |
| Chung et al. 2015 |
Mercury (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | Men: 1.62(1.15,1.36) | Yes | South Korea |
| Women: 0.84(0.57,1.24) | No | ||||||||
| Eom et al. 2014 |
Mercury (μg/dL) |
Categorical(q3/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | 1.68 (1.25–2.25) | Yes | South Korea |
| Lee et al. 2018 |
Mercury (μg/dL) |
Categorical(q4/q1) | Mets | Categorical |
The definition of MetS was based on the harmonized definition for MetS 2009 |
OR (95%CI) | Overall: 2.02(1.59,2.56) | Yes | South Korea |
| Men: 1.97(1.39,2.79) | |||||||||
| Women: 1.90(1.34,2.70) | |||||||||
| Cadmium | |||||||||
| Rotter et al. 2015 |
Cadmium (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on criteria of IDF | OR(95% CI) | 1.11(0.75,1.67) | No | Poland |
| Rhee et al. 2013 |
Cadmium (μg/dL) |
Categorical(q4/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.09 (0.65–1.83) | No | South Korea |
| Park et al. 2020 |
Cadmium (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) |
Male:1.28(0.13,12.20) Female: 33.79 (0.32,3596.31) |
No | Republic of Korea |
| Moon et al. 2014 |
Cadmium (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.91(0.73,1.14) | No | South Korea |
| Lee et al. 2012 |
Cadmium (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR ( 95% CI) | 1.23(1.047,1.447) | Yes | South Korea |
| Lee et al. 2017 |
Cadmium (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR ( 95% CI) | 1.10 (0.76,1.59) | No | South Korea |
| Lee et al. 2016 |
Cadmium (μg/dL) |
Categorical(q3/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.31 (1.05,1.62) | Yes | South Korea |
| Jin et al. 2013 |
Cadmium (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.58(1.15,2.2) | Yes | China |
| Han et al. 2015 |
Cadmium (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) |
Female: 0.52(0.23,1.19) Male: 3.05(1.38,6.70) |
No | Republic of Korea |
| Guo et al. 2019 |
Cadmium (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 2.2(1.03,4.72) | Yes | China |
| Duc et al. 2021 |
Cadmium (μg/dL) |
Continues | MetS | Categorical | American Heart Association/National Heart, Lung, and Blood Institute for clinical diagnosis | OR(95% CI) | 1.01(1.04,1.14) | Yes | Korea |
| Chromium | |||||||||
| Rotter et al. 2015 |
Chrome (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on IDF | OR(95% CI) | 0.92(0.60,0.78) | Yes | Poland |
| Jin et al. 2013 |
Chrome (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.65(0.48,0.78) | Yes | China |
| Chen et al. 2020 |
Chromium (μg/dL) |
Categorical(q4/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS in 2009 |
OR(95% CI) | 0.62(0.49,0.78) | Yes | China |
| Manganese | |||||||||
| Lo et al. 2021 |
Manganese (μg/dL) |
Categorical(q4/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | Overall: 0.66(0.38,1.14) | No | China |
| Men: 0.5(0.21,1.17) | No | ||||||||
| Women: 0.89(0.45,1.77) | No | ||||||||
| Rotter et al. 2015 | Manganese (μg/dL) | Continues | MetS | Categorical | Definition of MetS based on IDF | OR (95%CI) | 1.19(0.79,1.78) | No | Poland |
| Rhee et al. 2013 | Manganese (μg/dL) | Categorical(q4/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | 1.22 (0.76–1.97) | Yes | South Korea |
| Bulka et al. 2019 | Manganese (μg/dL) | Categorical(q3/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS |
PR (95% CI) | 1.04 (0.87–1.23) | No | USA |
| Jin et al. 2013 |
Manganese (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | 1.48(1.09,2.18) | Yes | China |
| Copper | |||||||||
| Rotter et al. 2015 |
Copper (mg/dL) |
Continues | MetS | Categorical | Definition of MetS based on IDF | OR (95%CI) | 0.90(0.60,1.35) | No | Poland |
| Jin et al. 2013 |
Copper (mg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | 1.4(1.1,2) | Yes | China |
| Guo et al. 2019 |
Copper (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 3.13(1.47,6.63) | Yes | China |
| Fang et al. 2019 |
Copper mg/L |
Categorical(q3/q1) | MetS | Categorical |
based on the Chinese guidelines for the prevention and treatment of dyslipidaemia in adults (2007) |
OR(95% CI) |
Male:0.91(0.49,1.70) Female:1.28(0.81,2.01) |
No | China |
| El Sayed et al. 2017 |
Copper (μg/dL) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.91(0.62,1.12) | No | Egypt |
| Bulka et al. 2019 |
Copper (μg/dL) |
Categorical(q3/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS |
PR (95% CI) | 0.94 (0.80–1.11) | No | USA |
| Lu et al. 2021 |
Iron (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 2.02 (1.25–3.25) | Yes | Taiwan |
| Magnesium | |||||||||
| El Sayed et al. 2017 |
Magnesium (mg/L) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 0.32(0.15,0.56) | Yes | Egypt |
| Rotter et al. 2015 | Magnesium (mg/L) | Continues | MetS | Categorical | Definition of MetS based on IDF | OR(95% CI) | 0.57(0.38,0.85) | Yes | Poland |
| Jin et al. 2013 |
Magnesium (mg/L) |
Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 1.23(0.89,1.68) | No | China |
| Iron | |||||||||
| Rotter et al. 2015 | Iron (μg /dL) | Continues | MetS | Categorical | Definition of MetS based on IDF | Mean (SD) |
MetS: 1.19 (0.45) Controls: 1.23 (0.43) |
MetS/Controls: No | Poland |
| Jin et al. 2013 | Iron (μg /dL) | Continues | MetS | Categorical | Definition of MetS based on NECP ATP III | Mean (SD) |
MetS: 15.52 (7.29) Controls: 15.84 (7.54) |
No | China |
| Arredondo et al. 2011 |
Iron (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | Mean (SD) |
MetS: 146.6 (59.2) Controls: 121.3 (51.9) |
MetS/Controls: Yes | Chile |
| Stechemesser et al. 2017 |
Iron (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | Mean (SD) |
MetS: 99.8(32.2) Controls:108.3(34.5) |
No | Austria |
| Ghamarchehreh et al. 2016 |
Iron (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | Mean (SD) |
MetS: 151.86(490.62) Controls:108.92(39.37) |
No | Iran |
| Tavakoli-Hoseini et al. 2014 |
Iron (μg/dL) |
Continues | Mets | Categorical | Definition of MetS based on NECP ATP III | Mean (SD) |
MetS: 133.2(64.8) Controls:102.4(44.7) |
Yes | Iran |
| Kilani et al. 2015 |
Iron (μg/dL) |
Categorical(q4/q1) | Mets | Categorical | Definition of MetS based on NECP ATP III | OR (95%CI) | Men: 0.81(0.53,1.24) | No | Switzerland |
| Women: 0.51(0.33,0.80) | Yes | ||||||||
| Chen et al. 2020 |
Iron (μg/dL) |
Categorical(q4/q1) | MetS | Categorical |
The definition of MetS was based on the harmonized definition for MetS in 2009 |
OR(95% CI) | 0.79(0.69,0.91) | Yes | China |
| Lu et al. 2021 |
Iron (μg/dL) |
Categorical(q4/q1) | MetS | Categorical | Definition of MetS based on NECP ATP III | OR(95% CI) | 2.11 (1.24–3.62) | Yes | Taiwan |