Table 1 General characteristics of included studies
Study | Country/Areas | Study period | Sample size (Boys/Girls) | Age range | Sample collection season | Analyte detection | Adjusted methods | Metabolites | Outcome indicators |
|---|---|---|---|---|---|---|---|---|---|
Chen 2015 [26] | Mongolia | 2011–2012 | 320 (166/154) | 11–15 years | Spring, autumn, winter | HPLC-FD | Creatinine | 1-OHPyr | Mean ± SD |
Hansen 2005 [27] | Denmark | 1994–1995 | 204 (108/96) | 7–8 years | Winter | HPLC-FD | Creatinine | 1-OHPyr | Mean (range) |
Kang 2002 [28] | Korea | 1997 | 137 (78/59) | 11–14 years | Summer | HPLC-FD | Creatinine | 1-OHPyr, 2-OHNap | Mean ± SD |
Mielzynska 2006 [29] | Poland | 1998–1999 | 74 (47/27) | 5–14 years | Winter | HPLC-FD | Creatinine | 1-OHPyr | Mean ± SD |
Miller 2010 [30] | USA | 1998–2006 | 222 (119/103) | 5 years | Irregular | GC-MS/MS | SG | 1-OHPyr, 1-OHNap, 2-OHNap, 2-OHFlu, 3-OHFlu, 9-OHFlu, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe | Mean (95% CI) |
Jung 2015 [31] | 9 years | ||||||||
Morgan 2015 [32] | USA | 2000–2001 | 126 (63/63) | 2– years | Spring, summer, autumn | GC/MS | Creatinine | 1-OHPyr | Mean ± SD |
Mucha 2006 [33] | Ukraine | 1998 | 90 (43/47) | 3 years | Spring | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Ochoa -Martinez 2016 [34] | Mexico | 2012 | 135(NA) | 6–12 years | Not mentioned | HPLC-FD | Creatinine | 1-OHPyr | Mean ± SD |
Yue 2010(1) [35] | China | 2007 | 80 (47/33) | 4–6 years | Winter | HPLC-FD | Creatinine | 1-OHPyr | Median (interquartile range) |
Yue 2011 [36] | 2-OHFlu, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean ± SD | |||||||
Alghamdi 2015 [37] | Saudi Arabian | 2013 | 170 (NA) | 11Â years | Spring | HPLC | Creatinine | 1-OHPyr, 3-OHFlu, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe | Median (interquartile range) |
Cirillo 2006 [38] | Italian | 2004 | 30 (15/15) | 7–9 years | Winter | HPLC-UV | Creatinine | 1-OHPyr | Mean ± SD |
Duan 2003 [39] | China | 2002 | 40 (NA) | Not mentioned | Winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Fan 2007 [40] | China | 2005 | 108 (72/36) | 16–18 years | Spring, summer | HPLC-MS/MS | Creatinine | 1-OHPyr, 1-OHNap, 2-OHNap, 2-OHFlu, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean ± SD |
Freire 2009 [41] | Spain | 2005–2006 | 174 (NA) | 4 years | Irregular | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Hu 2011 [42] | Taiwan/China | 2009 | 369 (198/171) | 1–13 years | Autumn, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Lee 2007 [43] | Korea | 2004 | 1012 (475/537) | 7–15 years | Spring | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Ruchirawat 2007 [44] | Thailand | 2006 | 176 (NA) | 9–13 years | Not mentioned | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Shahsavani 2016 [45] | Iran | 2015 | 120 (120/0) | 9–12 years | Spring | HPLC | Creatinine | 1-OHPyr | Mean (range) |
Su 2015 [46] | China | 2014 | 164 (NA) | Not mentioned | Autumn | HPLC-MS | Creatinine | 1-OHPyr, 1-OHNap, 2-OHNap, 2-OHFlu, 3-OHFlu, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean ± SD |
Wilhelm 2007 [47] | Germany | 2000 | 215 (NA) | 4–9 years | Spring | HPLC | Creatinine | 1-OHPyr | Median (range) |
Yang 1997 [48] | China | 1994 | 88 (88/0) | Not mentioned | Summer, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Yu 2012 [49] | China | 2010–2011 | 185 (NA) | 9–12 years | Winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Huang 2006 [50] | USA | 1999–2000 | 1003 (NA) | 6–19 years | Not mentioned | GC/IDHRMS | Creatinine | 1-OHPyr | Mean (95%CI) |
Huang 2014 [51] | China | 2009–2010 | 2015 (NA) | 6–20 years | Not mentioned | HPLC | Unadjusted | 1-OHPyrr, 1-OHNap, 2-OHNap, 3-OHPhe | Mean (95%CI) |
Li 2008 [52] | USA | 2001–2002 | 1122 (NA) | 6–19 years | Not mentioned | GC/IDHRMS | Creatinine | 1-OHPyr, 1-OHNap, 2-OHNap, 2-OHFlu, 3-OHFlu, 9-OHFlu, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean (95% CI) |
Heudorf 2001 [53] | Germany | 1998 | 718 (NA) | 0–20 years | Spring | HPLC-FD | Creatinine | 1-OHPyr, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe | Mean ± SD |
Yue 2010(2) [54] | China | 2006 | 15 (15/0) | 14–18 years | Winter | HPLC-FD | Creatinine | 1-OHPyr, 2-OHNap, 2-OHFlu, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean ± SD |
Yue 2009 [55] | China | 2005 | 41 (41/0) | 16–18 years | Summer | HPLC-FD | Creatinine | 1-OHPyr, 2-OHNap, 2-OHFlu, 2-OHPhe, 3-OHPhe, 4-OHPhe, 9-OHPhe | Mean ± SD |
Farzan 2016 [56] | USA | 2003–2008 | 660(NA) | 12–19 years | Not mentioned | GC/IDHRMS | Creatinine | 1-OHPyr, 1-OHNap, 2-OHNap, 2-OHFlu, 3-OHFlu, 9-OHFlu, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe | Mean ± SD |
Perez -Maldonado 2014 [57] | Mexico | 2008–2009 | 226 (112/114) | 6–12 years | Not mentioned | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Martinez -Salinas 2010 [58] | Mexico | 2010 | 258 (NA) | 3–13 years | Not mentioned | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Cavanagh 2007 [59] | New Zealand | 2004 | 89 (89/0) | 12–18 years | Autumn, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Wijnen 1996 [60] | The Netherlands | 1992 | 644 (NA) | 1–6 years | Summer | HPLC-FD | Creatinine | 1-OHPyr | Mean ± SD |
Ma 1996 [61] | China | 1992–1994 | 574 (NA) | Not mentioned | Summer, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Zhao 1995 [62] | China | 1991–1992 | 310 (310/0) | 6–15 years | Spring, autumn, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Ma 1994 [63] | China | 1992 | 145 (NA) | Not mentioned | Autumn, winter | HPLC | Creatinine | 1-OHPyr | Mean ± SD |
Kanoh 1993 [64] | Japan | 1988–1989 | 139 (NA) | Not mentioned | Summer, winter | HPLC | Unadjusted | 1-OHPyr | Mean ± SD |
Siwińska 1998 [65] | Poland | 1996 | 30 (18/12) | 8 years | Not mentioned | HPLC | Creatinine | 1-OHPyr | Median (range) |
Siwińska 1999 [66] | Poland | 1996 | 412(NA) | 7–8 years | Not mentioned | HPLC | Creatinine | 1-OHPyr | Median (range) |
Fiala 2001 [67] | The Czech Republic | 1997–1998 | 57(NA) | 3–6 years | Summer, winter | HPLC-FD | Creatinine | 1-OHPyr | Mean (range) |