Table 2 Association between BMI and type 1 diabetes and risk of bias across included studies (n = 10)

Carlsson et al. [25]

0.38 (0.10-1.36)^a

1.16 (0.25–5.41)

0.92 (0.78–1.08)

Sex, age, smoking

7

Viner et al. [19]

-

3.1 (1.0–9.3)

1.8 (1.2–2.8)

Sex, maternal educational, birth weight, puberty stage, breastfeeding, social class

7

Harpsøe et al. [24]

1.42 (0.95–2.14)

2.67 (1.71–4.17)

1.07 (1.04–1.11)

Smoking, alcohol, parity, socio-occupational status

8

Tosur et al. [20]

1.37 (1.05–1.79)^b

–

1.00 (0.997–1.004)

Sex, number of Abs (single vs. multiple), DPTRS, HLA-genotype

8

Nucci et al. [21]

1.26 (0.71–2.21)^b

1.59 (0.50–5.08)

N/A^c

Sex, birth weight z-score, birth length z-score, HLA risk, maternal type 1 diabetes, mode of delivery, breastfeeding duration (> \ < 6 months)

8

Herzog et al. [23]

1.88 (1.43–2.47)^b

–

N/A^c

Sex, age (timescale), calendar time, fasting status (overnight fasting vs. no fasting), socioeconomic status, country of birth

7

Zucker et al. [15]

1.54 (1.23–1.94)

2.05 (1.58–2.66)

1.25 (1.17–1.32)

Sex, age, birth year, education, cognitive score

8

Ferrannini et al. [16]

N/A^d

N/A^d

Females: 2.25 (1.31–3.79)^a Males: 1.27 (0.72–2.13)^a

Age, ß-cell glucose sensitivity insulin sensitivity, projective 5-year risk of diabetes (high vs. moderate)

7

Steck et al. [18]

N/A^d

N/A^d

0.86 (0.72–1.02)

Unadjusted

7

So et al. [17]

N/A^d

N/A^d

1.2 (1.11–1.31)

Unadjusted

7