Table 1.
Characteristics of the included studies according to the WHO 1999 classification criteria.
| Author (year) | Study group | Study duration (year) | Study location | Baseline (n) | Baseline (n) | Baseline (n) | Baseline (n) | Effects estimator | Adjusted covariate | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WHO NFG+NGT | WHO I-IFG | WHO I-IGT | WHO IGT+IFG | ||||||||||
| Total number of population | Number of progression to T2DM | Total number of population | Number of progression to T2DM | Total number of population | Number of progression to T2DM | Total number of population | Number of progression to T2DM | ||||||
| Gabir (2000) (21) | Pima | 5 | North America | 3,499 | 126 | 93 | 29 | 537 | 107 | 126 | 52 | – | – |
| Vegt (2001) (22) | Hoorn | 6.4 | European | 1,125 | 51 | 106 | 35 | 80 | 27 | 31 | 20 | OR | Adjusted for follow-up duration, age, and sex. |
| Li (2003) (23) | Kinmen | 5 | Asia | 435 | 38 | 42 | 16 | 118 | 33 | 49 | 20 | HR | Adjusted for gender, age, and obesity. |
| Qiao (2003) (24) | FINMONICA | 10 | European | 2,129 | 44 | 104 | 5 | 322 | 34 | 38 | 17 | HR | Adjusted for age, sex, BMI, HDL, and WHR. |
| Wang (2004) (25) | – | 5 | Asia | 358 | 51 | 112 | 28 | 95 | 31 | 62 | 36 | OR | Grouped by sex and adjusted for age, smoking, SBP, BMI, family history of diabetes, total cholesterol, and triglycerides. |
| Valdes (2007) (26) | Asturias | 6 | Oceania | 510 | 16 | 32 | 7 | 68 | 9 | 20 | 12 | OR | Adjusted for age and sex. |
| Jia (2007) (27) | – | 3 | Asia | 2,260 | 45 | 39 | 12 | 284 | 51 | 40 | 22 | – | – |
| Harati (2009) (28) | TLGS | 6 | Asia | 3,216 | 94 | 60 | 12 | 442 | 85 | 77 | 46 | OR | Adjusted for age, sex, education level, family history of diabetes, hypertension, BMI, Abdominal obesity, triglyceride, and HDL. |
| Engberg (2009) (29) | Inter 99 Study | 5 | European | 3,187 | 44 | 359 | 45 | 354 | 66 | 131 | 52 | – | – |
| Qian (2012) (31) | – | 5 | Asia | 843 | 59 | 46 | 17 | 120 | 49 | 33 | 17 | – | – |
| Liu (2019) (34) | Reaction study | 3 | Asia | 2,833 | 188 | 640 | 144 | 790 | 129 | 314 | 95 | – | – |
NFG+NGT, normal fasting glucose combined with normal glucose tolerance; I-IFG, isolated impaired fasting glucose; I-IGT, isolated impaired glucose tolerance; IGT+IFG, impaired fasting glucose combined with impaired glucose tolerance; T2DM, type 2 diabetes.