Table 3 Subgroup analysis for risk of T1DM.

From: A dose–response meta-analysis between serum concentration of 25-hydroxy vitamin D and risk of type 1 diabetes mellitus

Subgroup

No. of studies

Risk of T1DMa

I2, %

Pwithinb

Pbetweenc

  

OR

95% CI

   

Overall

16

0.39

(0.27, 0.57)

76.70%

  

Age

      

 Only children

12

0.40

(0.24, 0.64)

81.1

<0.001

0.77

 Other

4

0.36

(0.26, 0.50)

0.0

0.53

 

Ethnicity

      

 White

2

0.42

(0.25, 0.72)

0.0

0.33

0.16

 Yellow

2

0.29

(0.19, 0.45)

0.0

0.65

 

 Mix

6

0.65

(0.4, 1.05)

73.4

0.002

 

Latitude, °N

      

 ≤30

5

0.29

(0.16, 0.54)

55.3

0.06

0.02

 31–45

9

0.35

(0.26, 0.47)

36.4

0.13

 

 >45

2

1.15

(0.85, 1.57)

0.0

0.75

 

Categories of 25(OH)D, nmol/L

      

 ≤50

1

0.67

(0.39, 1.15)

NA

NA

 < 0.001

 50–75

5

0.27

(0.18, 0.41)

16.8

0.31

 

 75–100

2

1.15

(0.85, 1.57)

0.0

0.75

 

 >100

8

0.33

(0.24, 0.45)

26.3

0.22

 

Assay method of 25(OH)D

      

 RIA

2

0.39

(0.17, 0.89)

68.5

0.08

0.10

 HPLC

3

0.24

(0.13, 0.45)

17.9

0.30

 

 CPBA

1

0.03

(0.00, 0.48)

NA

NA

 

 CLIA

3

0.38

(0.26, 0.56)

0.0

0.61

 

 ELISA

4

0.27

(0.19, 0.38)

0.0

0.62

 

 LC-MS

3

0.98

(0.68, 1.42)

33.6

0.22

 

Duration of T1DM

      

 >1year

3

0.25

(0.13, 0.47)

17.3

0.30

0.50

 <1year

2

0.38

(0.16, 0.89)

0.0

0.64

 

Adjustment for ethnicity

      

 Yes

6

0.40

(0.26, 0.60)

58.1

0.04

0.98

 No

10

0.38

(0.22, 0.68)

81.9

<0.001

 

Adjustment for gender

      

 Yes

11

0.31

(0.25, 0.39)

17.3

0.28

0.001

 No

5

0.80

(0.46, 1.39)

59.8

0.04

 
  1. T1DM type 1 diabetes, N number, OR odds ratio, 95% CI 95% confidential interval.
  2. aSummary OR and 95%CI were calculated by random-effects models.
  3. bPwithin was the P value for heterogeneity within each subgroup.
  4. cPbetween calculated by meta-regression was the P value for heterogeneity between subgroups