Table 2.
Characteristics of studies about TGF-β (μg/L) included in this meta-analysis.
| Author | Year | Country | Case | Control | NOS score | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SZ | M/F | Mean | SD | SZ | M/F | Mean | SD | ||||
| Azar [47] | 1999 | Lebanon | 26 | 8/18 | 0.558 | 0.107 | 27 | 10/17 | 0.593 | 0.064 | 8 |
| Azara [48] | 2000 | Lebanon | 8 | 3/5 | 10.8 | 2.3 | 15 | 9/6 | 4.1 | 0.5 | 8 |
| Azarb [48] | 2000 | Lebanon | 9 | 2/7 | 9.9 | 2.8 | 15 | 9/6 | 4.1 | 0.5 | 8 |
| Azarc [48] | 2000 | Lebanon | 8 | 5/3 | 10.7 | 2.2 | 15 | 9/6 | 4.1 | 0.5 | 8 |
| Jun-Wen [49] | 2007 | China | 61 | 35/26 | 315.9 | 224.59 | 19 | 10/9 | 68.47 | 31.75 | 7 |
| Chi [50] | 2013 | China | 20 | 11/9 | 18.55 | 2.67 | 18 | 10/8 | 8.97 | 4.087 | 8 |
| Chi∗ [50] | 2013 | China | 20 | 9/11 | 19.04 | 2.87 | 18 | 10/8 | 8.97 | 4.087 | 8 |
| Chi∗∗ [50] | 2013 | China | 21 | 13/8 | 18.12 | 3.17 | 18 | 10/8 | 8.97 | 4.087 | 8 |
| Ehnert [51] | 2015 | Germany | 14 | 7/7 | 35.3 | 2.4 | 13 | 7/6 | 39.5 | 1.4 | 8 |
| Changxin [52] | 2007 | China | 34 | 24/10 | 36.2 | 8.8 | 35 | 24/11 | 34.4 | 8.2 | 7 |
| Changxin∗ [52] | 2007 | China | 31 | 21/10 | 69.4 | 12.8 | 35 | 24/11 | 34.4 | 8.2 | 7 |
| Hellmich [53] | 2000 | Germany | 35 | 16/19 | 9.5 | 2.1 | 12 | 5/7 | 0.24 | 0.03 | 8 |
| Hellmich∗ [53] | 2000 | Germany | 23 | 8/15 | 10.8 | 2.1 | 12 | 5/7 | 0.24 | 0.03 | 8 |
| Herder [54] | 2009 | Germany | 460 | 255/205 | 35.8 | 0.4 | 1474 | 724/750 | 35 | 0.2 | 8 |
| Hai-bing [55] | 2001 | China | 14 | 7/7 | 35.02 | 6.7 | 15 | 7/8 | 23.95 | 8.01 | 6 |
| Hai-bing∗ [55] | 2001 | China | 13 | 5/8 | 58.58 | 9.56 | 15 | 7/8 | 23.95 | 8.01 | 6 |
| Hai-bing∗∗ [55] | 2001 | China | 18 | 9/9 | 39.31 | 5.35 | 15 | 7/8 | 23.95 | 8.01 | 6 |
| Zhen-zuo [56] | 2005 | China | 27 | 14/13 | 41 | 15.57 | 18 | 9/9 | 10.04 | 5.33 | 7 |
| Zhen-zuo∗ [56] | 2005 | China | 12 | 7/5 | 66.35 | 18.04 | 18 | 9/9 | 10.04 | 5.33 | 7 |
| Zhen-zuo∗∗ [56] | 2005 | China | 18 | 9/9 | 53.31 | 15.64 | 18 | 9/9 | 10.04 | 5.33 | 7 |
| Rui-Ji [57] | 2011 | China | 32 | NR | 35 | 5 | 20 | NR | 25 | 5 | 6 |
| Rui-Ji∗ [57] | 2011 | China | 31 | NR | 69 | 7 | 20 | NR | 25 | 5 | 6 |
| Rui-Ji∗∗ [57] | 2011 | China | 32 | NR | 54 | 6 | 20 | NR | 25 | 5 | 6 |
| Da-wei∗ [58] | 2013 | China | 15 | NR | 234.2 | 29.8 | 45 | NR | 69.4 | 12.5 | 7 |
| Da-wei∗∗ [58] | 2013 | China | 32 | NR | 155.6 | 19.3 | 45 | NR | 69.4 | 12.5 | 7 |
| Pfeiffer [59] | 1996 | Germany | 44 | 22/22 | 7.9 | 1 | 28 | 16/12 | 3.1 | 0.4 | 8 |
| Yan-Jun [60] | 2002 | China | 34 | 16/18 | 147.03 | 22.57 | 35 | 17/18 | 136.97 | 37.96 | 7 |
| Yan-Jun∗ [60] | 2002 | China | 31 | 15/16 | 170.65 | 18.74 | 35 | 17/18 | 136.97 | 37.96 | 7 |
| Yaping [61] | 2008 | China | 44 | NR | 35.4 | 7.1 | 35 | NR | 32.5 | 6.8 | 7 |
| Yaping∗ [61] | 2008 | China | 32 | NR | 68.2 | 12.5 | 35 | NR | 32.5 | 6.8 | 7 |
| Ye-Sheng [62] | 2005 | China | 92 | 42/50 | 36.89 | 9.75 | 105 | 50/55 | 25.46 | 7.88 | 6 |
| Ye-Sheng∗ [62] | 2005 | China | 91 | 40/51 | 41.57 | 10.55 | 105 | 50/55 | 25.46 | 7.88 | 6 |
| Ming-bin [63] | 2002 | China | 15 | NR | 25.85 | 6.09 | 15 | 8/7 | 21.4 | 5.62 | 6 |
| Ming-bin∗ [63] | 2002 | China | 18 | NR | 38.53 | 3.98 | 15 | 8/7 | 21.4 | 5.62 | 6 |
| Ming-bin∗∗ [63] | 2002 | China | 16 | NR | 31.15 | 3.51 | 15 | 8/7 | 21.4 | 5.62 | 6 |
| Chun-Yan [64] | 2005 | China | 92 | NR | 45.57 | 21.78 | 20 | NR | 24.58 | 12.61 | 7 |
| Yener [23] | 2008 | Turkey | 39 | 18/21 | 29.84 | 7.04 | 30 | 16/14 | 11.37 | 4.06 | 8 |
| Yuan [65] | 2011 | China | 51 | 37/14 | 1.7399 | 0.4846 | 55 | 40/15 | 2.1045 | 0.5327 | 7 |
| Wei-jie [66] | 2007 | China | 36 | 19/17 | 23.35 | 3.7 | 40 | 23/17 | 20.35 | 3.7 | 7 |
| Wei-jie∗ [66] | 2007 | China | 45 | 25/20 | 55.28 | 6.8 | 40 | 23/17 | 20.35 | 3.7 | 7 |
| Wei-jie∗∗ [66] | 2007 | China | 45 | 23/22 | 41.31 | 4.3 | 40 | 23/17 | 20.35 | 3.7 | 7 |
| Zhou [67] | 2005 | China | 30 | NR | 31.12 | 12.39 | 30 | NR | 29.4 | 10.62 | 8 |
| Zhou∗ [67] | 2005 | China | 30 | NR | 136.6 | 21.45 | 30 | NR | 29.4 | 10.62 | 8 |
| Zhou∗∗ [67] | 2005 | China | 30 | NR | 79.63 | 15.96 | 30 | NR | 29.4 | 10.62 | 8 |
DM: diabetes mellitus; SZ: sample size; M/F: man/female; SD: standard deviation; NR: not reported. ∗,∗∗T2DM with different complication; a,b,cT2DM with different duration limited.