Table 1.
Characteristics of subjects in eligible studies
| Studies | Country | Age (year) | Type of Mn measurement | Sample specimen | Breast cancer | Healthy controls | Weight (%) | SMD (95% CI) | Quality score | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
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|
|
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| Breast cancer | Healthy control | N | Mn concentration (mean ± SD) | N | Mn concentration (mean ± SD) | |||||||
| Bai 2000 | China | 32~65 | 32~65 | ICP-AAS | Hair | 38 | 1.01 ± 0.62 ng/g | 38 | 6.78 ± 4.19 ng/g | 9.11 | -1.93 (-2.47, -1.38) | 6 |
| Kilic 2004 | Turkey | 53±9 | 55 ± 7 | GFAAS | Hair | 26 | 0.67 ± 0.52 μg/g | 27 | 1.66 ± 0.4 μg/g | 8.97 | -2.12 (-2.80, -1.44) | 7 |
| Dai 2005 | China | 28~58 | 23~68 | ICP-AAS | Serum | 54 | 0.18 ± 0.07 μmol/l | 56 | 1.44 ± 0.84 μmol/l | 9.18 | -2.10 (-2.56, -1.63) | 7 |
| Liang 2005 | China | 32~68 | 22~58 | ICP-AAS | Serum | 28 | 0.08 ± 0.01 μmol/l | 22 | 1.52 ± 0.88 μmol/l | 8.88 | -2.47 (-3.22, -1.73) | 7 |
| Wu 2006 | China | NA | NA | ICP-AES | Serum | 25 | 5.5 ± 0.47 μg/l | 26 | 9.09 ± 1.25 μg/l | 8.63 | -3.77 (-4.70, -2.85) | 5 |
| Li 2006 | China | 20~70 | 20~70 | ICP-AAS | Serum | 78 | 1.71 ± 0.11 μg/dl | 61 | 1.65 ± 0.18 μg/dl | 9.28 | 0.41 (0.08, 0.75) | 7 |
| Li 2008 | China | 49.9 ± 10.7 | 20~70 | ICP-AAS | Serum | 93 | 1.75 ± 0.16 μg/dl | 81 | 1.64 ± 0.17 μg/dl | 9.30 | 0.67 (0.36, 0.97) | 7 |
| Joo 2009 | Korea | 47.1 ± 9.6 | 47.8 ± 5.1 | ICP-AAS | Hair | 40 | 0.21 ± 0.04 μg/g | 144 | 0.44 ± 0.0 μg/g | 9.11 | -4.08 (-4.63, -3.54) | 7 |
| Wang 2010 | China | 25~60 | 26~60 | ICP-AAS | Serum | 25 | 0.24 ± 0.41 μmol/l | 260 | 0.22 ± 0.2 μmol/l | 9.23 | 0.10 (-0.31, 0.51) | 7 |
| Cihan 2011 | Turkey | 50.3 ± 8.8 | 47.4 ± 10.1 | ICP-AAS | Hair | 52 | 0.989 ± 0.924 μg/g | 52 | 0.863 ± 0.675 μg/g | 9.25 | 0.16 (-0.23, 0.54) | 7 |
| Feng 2012 | China | 48.7 ± 8.4 | 47.2 ± 7.6 | GFAAS | Serum | 56 | 8.3 ± 1.57 μg/l | 20 | 10.95 ± 1.14 μg/l | 9.07 | -1.80 (-2.39, -1.21) | 7 |
ICP-AAS, inductively coupled plasma-atomic absorption spectrometry. ICP-AES, inductively coupled plasma-atomic emission spectrometry. GFAAS, graphite furnace atomic absorption spectroscopy.