Table 2 Stratified meta-analysis of associations between high TSH and low TSH levels with T2DM risk

Age, years^a

 < 60

9

1.104 (0.965; 1.263)

0.182

5

1.113 (0.945; 1.309)

0.299

 ≥ 60

4

1.376 (1.025; 1.847)

4

0.897 (0.618; 1.302)

Sex

 Women (≥ 50%)

9

1.252 (1.058; 1.483)

0.065

6

1.003 (0.752; 1.337)

0.521

 Women (< 50%)

4

0.978 (0.799; 1.197)

3

1.120 (0.938; 1.337)

Study location

 Asia

6

1.264 (0.997; 1.604)

0.377

5

1.099 (0.852; 1.417)

0.251

 Europe & the USA

6

1.113 (0.955; 1.298)

3

0.851 (0.596; 1.215)

BMI, kg/m^2a

 Normal

2

1.404 (1.072; 1.840)

0.005

2

1.093 (0.780; 1.533)

0.238

 Overweight/obese

5

1.009 (0.945; 1.077)

2

0.784 (0.579; 1.062)

 Not Reported

5

1.381 (1.074; 1.777)

4

1.096 (0.785; 1.530)

Follow-up years

 ≤ 5 years

4

1.004 (0.912; 1.105)

0.024

2

1.141 (0.955; 1.363)

0.251

 > 5 years

9

1.263 (1.060; 1.505)

7

0.959 (0.757; 1.216)

Thyroid medicine users

 No

9

1.204 (1.002; 1.447)

0.617

4

0.899 (0.773; 1.045)

0.007

 Mixed (yes & no)

4

1.084 (0.900; 1.306)

2

1.076 (0.828; 1.398)

 Not Reported

2

1.057 (0.846; 1.321)

3

1.236 (1.155; 1.322)

Sample size

 ≤ median

6

1.234 (0.953; 1.599)

0.587

3

0.844 (0.592; 1.202)

0.071

 > median

6

1.138 (0.989; 1.309)

5

1.190 (1.058; 1.340)

Quality score

 6 stars

4

1.127 (0.940; 1.350)

0.240

3

1.156 (0.942; 1.419)

0.405

 7 stars

5

1.075 (0.908; 1.272)

2

1.050 (0.845; 1.304)

 8 stars

3

1.502 (1.057; 2.134)

3

0.806 (0.490; 1.326)

Outcomes

 T2DM

5

1.059 (0.944; 1.188)

0.127

4

0.970 (0 .750; 1.256)

0.722

 T2DM & T1DM

7

1.297 (1.048; 1.606)

4

1.057 (0.7 11; 1 .574)