Table 1. Main characteristics of studies included in this meta-analysis.
| Mean age | Total | Definition | BMI | ||||||
|---|---|---|---|---|---|---|---|---|---|
| First author's Last name | Year | Country | Case/Control | Cases Controls | Cases | Controls | Case/Control | Genotype method | |
| MTNR1B | |||||||||
| Deng | 2011 | China | 31.8/29.7 | 87 | 91 | OGTT confirmed | Normal glucose tolerant | 23.6/21.5 | Sequencing |
| Kim | 2011 | Korea | 33.1/32.2 | 928 | 990 | OGTT confirmed | Normal glucose tolerant | 23.32/21.40 | TaqMan |
| Wang | 2011 | China | 32/30 | 725 | 1039 | OGTT confirmed | Normal glucose tolerant | 21.72/21.48 | TaqMan |
| Vlassi | 2012 | Greece | 35.4/31.3 | 77 | 98 | ADA criteria | Normal glucose tolerant | 25.83/26.76 | PCR-RFLP |
| Li | 2013 | China | 32.4/31.9 | 350 | 480 | OGTT and IADPSG | Normal glucose tolerant | 25.34/24.69 | PCR-RFLP |
| IRS1 | |||||||||
| Shaat | 2005 | Sweden | 32.2/30.5 | 587 | 1189 | EASD-DPSG criteria | Normal glucose tolerant | 24.5/23.1 | TaqMan |
| Fallucca | 2006 | Italy | 34.1/32.7 | 309 | 277 | OGTT confirmed | Normal glucose tolerant | 23.4/22.8 | PCR-RFLP |
| Tok | 2006 | Turkey | - | 62 | 100 | NDDG criteria | Normal glucose tolerant | 25.1/24.7 | PCR-RFLP |
| Pappa | 2011 | Greece | 32.5/26.6 | 148 | 107 | Fourth IWCGDM criteria | Normal glucose tolerant | 26/24 | PCR-RFLP |
| Alharbi | 2014 | Saudi | 32.4/31.3 | 200 | 300 | OGTT confirmed | Normal glucose tolerant | 34.4/33.3 | PCR-RFLP |
OGTT, the oral glucose tolerance test; ADA, the American Diabetes Association; IADPSG, the International Association of Diabetes in Pregnancy Study Groups;
EASD-DPSG, the European Association for the Study of Diabetes-Diabetic Pregnancy Study Group; IWCGDM, International Workshop-Conferences on Gestational Diabetes Mellitus.