| No. of effect sizes | Fisher’s Z (95% CI) | P withina | I2 (%) | P betweenb |
---|---|---|---|---|---|
Subgroup analyses for NC and FBG | |||||
 Race | < 0.001 | ||||
  USA | 8 | 0.23 (0.15 to 0.31) | < 0.001 | 87.1 |  |
  Mideast | 4 | 0.21 (0.04 to 0.37) | < 0.001 | 93.4 |  |
  Asian | 17 | 0.15 (0.12 to 0.18) | < 0.001 | 82.0 |  |
  Latin America | 4 | 0.20 (0.17 to 0.23) | 0.241 | 28.5 |  |
  European | 2 | 0.45 (0.28 to 0.62) | 0.170 | 46.9 |  |
 Adjustments | 0.055 | ||||
  Yes | 22 | 0.18 (0.14 to 0.21) | < 0.001 | 87.5 |  |
  No | 13 | 0.20 (0.15 to 0.24) | < 0.001 | 85.8 |  |
 Correlation type | 0.059 | ||||
  Pearson | 30 | 0.18 (0.15 to 0.21) | < 0.001 | 87.5 |  |
  Spearman | 5 | 0.25 (0.14 to 0.36) | < 0.001 | 82.1 |  |
 Health status | 0.045 | ||||
  Patients | 4 | 0.17 (0.07 to 0.28) | 0.084 | 54.8 |  |
  Healthy | 31 | 0.19 (0.16 to 0.21) | < 0.001 | 87.7 |  |
 Sampling method | 0.007 | ||||
  Consecutive | 6 | 0.25 (0.16 to 0.34) | < 0.001 | 79.5 |  |
  Random | 19 | 0.16 (0.13 to 0.20) | < 0.001 | 90.5 |  |
  Non-random | 10 | 0.21 (0.15 to 0.28) | < 0.001 | 71.4 |  |
Subgroup analyses for NC and serum fasting insulin level | |||||
 Race | < 0.001 | ||||
  USA | 5 | 0.43 (0.34 to 0.53) | < 0.001 | 81.1 |  |
  Mideast | 2 | 0.33 (0.22 to 0.44) | 0.015 | 83.1 |  |
  Asian | 2 | 0.10 (0.06 to 0.13) | 0.640 | 0.0 |  |
  Latin America | 4 | 0.36 (0.29 to 0.43) | < 0.001 | 87.0 |  |
  European | 2 | 0.41 (0.24 to 0.58) | 0.178 | 44.8 |  |
 Adjustments | 0.35 | ||||
  Yes | 12 | 0.34 (0.25 to 0.42) | < 0.001 | 96.5 |  |
  No | 3 | 0.33 (0.12 to 0.55) | 0.014 | 76.5 |  |
 Correlation type | 0.016 | ||||
  Pearson | 11 | 0.34 (0.25 to 0.43) | < 0.001 | 96.8 |  |
  Spearman | 4 | 0.32 (0.22 to 0.41) | 0.089 | 54.0 |  |
 Health status | 0.35 | ||||
  Patients | 3 | 0.32 (0.22 to 0.42) | 0.014 | 76.5 |  |
  Healthy | 12 | 0.37 (0.36 to 0.38) | < 0.001 | 96.5 |  |
 Sampling method | 0.001 | ||||
  Consecutive | 1 | 0.55 (0.36 to 0.75) | – | – |  |
  Random | 8 | 0.34 (0.24 to 0.45) | < 0.001 | 97.7 |  |
  Non-random | 6 | 0.29 (0.22 to 0.36) | 0.137 | 40.2 |  |
Subgroup analyses for NC and HOMA-IR | |||||
 Race | < 0.001 | ||||
  USA | 3 | 0.53 (0.49 to 0.57) | 0.122 | 52.6 |  |
  Mideast | 2 | 0.34 (0.28 to 0.39) | 0.222 | 32.9 |  |
  Asian | 5 | 0.20 (0.13 to 0.270 | < 0.001 | 85.0 |  |
  Latin America | 4 | 0.43 (0.39 to 0.48) | 0.010 | 73.4 |  |
  European | 2 | 0.39 (0.27 to 0.52) | 0.885 | 0.0 |  |
 Adjustments | < 0.001 | ||||
  Yes | 14 | 0.38 (0.31 to 0.45) | < 0.001 | 95.3 |  |
  No | 2 | 0.24 (0.13 to 0.36) | 0.001 | 90.1 |  |
 Correlation type | 0.547 | ||||
  Pearson | 12 | 0.35 (0.27 to 0.43) | < 0.001 | 96.8 |  |
  Spearman | 4 | 0.40 (0.33 to 0.47) | 0.248 | 27.3 |  |
 Health status | 0.001 | ||||
  Patients | 1 | 0.48 (0.43 to 0.54) | – | – |  |
  Healthy | 15 | 0.35 (0.28 to 0.42) | < 0.001 | 95.9 |  |
 Sampling method | 0.701 | ||||
  Random | 11 | 0.36 (0.28 to 0.44) | < 0.001 | 97.1 |  |
  Non-random | 5 | 0.39 (0.32 to 0.46) | 0.266 | 23.3 |  |
Subgroup analyses for NC and HbA1c | |||||
 Race | < 0.001 | ||||
  USA | 4 | 0.23 (0.15 to 0.32) | 0.168 | 40.6 |  |
  Asian | 7 | 0.05 (0.02 to 0.09) | 0.025 | 58.4 |  |
  Latin America | 2 | 0.21 (0.15 to 0.27) | 0.879 | 0.0 |  |
  European | 2 | 0.20 (0.07 to 0.32) | 0.797 | 0.0 |  |
 Adjustments | < 0.001 | ||||
  Yes | 10 | 0.17 (0.10 to 0.24) | < 0.001 | 81.6 |  |
  No | 5 | 0.06 (0.00 to 0.11) | 0.015 | 67.4 |  |
 Correlation type | < 0.001 | ||||
  Pearson | 11 | 0.12 (0.06 to 0.18) | < 0.001 | 88.9 |  |
  Spearman | 4 | 0.20 (0.15 to 0.26) | 0.992 | 0.0 |  |
 Health status | < 0.001 | ||||
  Patients | 4 | 0.23 (0.15 to 0.32) | 0.168 | 40.6 |  |
  Healthy | 11 | 0.11 (0.06 to 0.15) | < 0.001 | 78.7 |  |
 Sampling method | < 0.001 | ||||
  Consecutive | 1 | 0.10 (− 0.10 to 0.29) | – | – |  |
  Random | 5 | 0.10 (0.01 to 0.18) | < 0.001 | 94.8 |  |
  Non-random | 9 | 0.18 (0.13 to 0.23) | 0.281 | 18.2 |  |