Table 1.
Characteristics of the included studies in the meta-analysis.
| Author, year | Country | Study design | Geographic Location | NOS | Participants | ||||
|---|---|---|---|---|---|---|---|---|---|
| Region | Latitude, °N | Ethnicity, case/control | No. of gender, male/female | Age of cases/controls, year | BMI of cases/controls, kg/m2 | ||||
| Bener [21] | Qatar | case-control study | Doha | 25 | 8 | White, wheat, brown or black people | 168/172 | 10.5 ± 3.8/9.9 ± 4.2 | 16.76/17.88 |
| Borkar [35] | India |
cross-sectional case-control study |
Chandigarh | 31 | 8 | NA | 55/45 | 8.63 ± 2.01/8.48 ± 1.58 | 15.74 ± 1.88/16.25 ± 2.43 |
| Hamed [22] | India | case-control study | Assuit | 27 | 7 | NA | 20/31 | 10.38 ± 3.17/8.47 ± 4.17 | 17.83 ± 7.07/16.42 ± 2.88 |
| Gorham [33] | USA | nested case-control study | San Diego | 32 | 7 | White, black, and other | NA | 33.28/33.26 | NA |
| Ghandchi [23] | Iran | case-control study | Tehran | 35 | 8 | NA | 58/62 | 14.4(0.5)/14.6(0.8)a | 21.4(0.6)/20.8(0.7)a |
| Munger [34] | USA | nested case-control study | Boston | 42 | 7 | Non-Hispanic Whites | 439/23 | 20.6 ± 4.1/20.6 ± 4.0 | NA |
| Franchi [26] | Italy | case-control study | Verona | 45 | 4 | Caucasian and other | 124/100 | 9.2(1.1–16.0)/8.7(1.1–16.3)b | 16.6(11.4–25.8)/16.9(11.0–38.3)b |
| Azab [24] | Egypt | case-control study | Zagazig | 30 | 7 | NA | 58/62 | 11.4 ± 2.5/10.8 ± 2.3 | 23.6 ± 5.7/21.8 ± 4.7 |
| Abd-Allah [25] | Egypt | case-control study | Zagazig | 30 | 6 | NA | 90/150 | 11.7 ± 2.8/11.1 ± 2.6 | 18.5 ± 4.3/21.6 ± 1.5 |
| Cadario [27] | Italy | case-control study | Novara | 45 | 6 | Italian, Northern African, and Eastern European | 145/158 | 7.0 ± 0.25/7.2 ± 0.49 | NA |
| Jacobsen [28] | Denmark | case-cohort study | Denmark | 55 | 6 | Danish, other western, other non-western | 1933/1852 | 10.2(7.5,12.5)/10.5(5.1,11.5)c | NA |
| Jacobsen [28] | Denmark | case-control study | Denmark | 55 | 9 | Danish, other western, other non-western | 551/503 | 8.5(5.0,22.4)/NAc | NA |
| Rasoul [29] | Kuwait | case-control study | Safat | 29 | 8 | Kuwaiti Arab | 210/210 | 9.59 ± 3.20/9.60 ± 2.73 | NA |
| Bae [30] | Korea | case-control study | Seoul | 37 | 9 | Korean | 276/327 | 14.5 ± 4.4/13.8 ± 3.8 | SDS: −0.01 ± 0.95/−0.09 ± 1.19 |
| Liu [32] | China | case-control study | Nanjing | 32 | 8 | Chinese | 295/296 | 8.66 ± 3.75/8.40 ± 3.60 | NA |
| Federico [31] | Italy | case-control study | Varese, Pisa | 45 | 5 | NA | 107/92 | 9.5 ± 3.8(5.0)/9.4 ± 3.9(6.5)d | NA |
T1DM type 1 diabetes mellitus, NOS Newcastle–Ottawa Scale, BMI body mass index, NA not available, N number, SDS standard deviation score.
aAge and BMI were presented as mean ± standard deviation except a was mean (standard error).
bMedian, full range (min–max).
cMedian (interquartile range).
dMedian ± standard deviation (interquartile range).