Table 1.
Characteristics of included studies
| Study and publication year | Country | Population characteristics* | Sample size of cohorts (% women) | Average age (range or SD) | Years of follow-up in all participants (% followed up to or died before stated time point) | Prevalence of pre-diabetes | Baseline pre-diabetes category and definition | Endpoint assessed during follow-up | Adjustment variables | Adjustment for confounders† |
|---|---|---|---|---|---|---|---|---|---|---|
| Doi 201021 | Japan | General, excluded history of CVD (excluded all diabetes) | 2421 (57%) | 58 (10) | 14 (100%) | NA | IFG 100 , IFG 110, IGT | Ischaemic stroke | Age, sex, SBP, ECG abnormalities, BMI, total and HDL cholesterol, smoking habits, alcohol intake, and regular exercise | Adequate |
| Hyvärinen 200922 | Finland, Sweden | General (excluded all diabetes) | 18 360 (54%) | 55 (20-90) | 12.9 (not reported) | 22% | IFG 110, IGT | All stroke | Age, sex, centre, MAP, BMI, total cholesterol, and smoking status | Adequate |
| Iso 200423 | Japan | General, excluded history of CVD (excluded all diabetes) | 10 582 (59%) | 53 (40-69) | 17 (not reported) | 7% | IFG 110, IGT | Ischaemic stroke | Age, sex, community, hypertension status, BMI, TSF, SSF, total and HDL cholesterol, smoking status, alcohol intake, and (for women) menopausal status | Adequate |
| Janszky 200924 | Sweden | CAD (might include non-fasting glucose ≥200 mg/dL) | 1167 (30%) | 59 (45-70) | 8 (not reported) | 22% | IFG 100 | All stroke | Age, sex, obesity, hypertension, physical activity, total cholesterol, triglycerides, apo B:apo A ratio, Q wave infarction, and education | Adequate |
| Kaarisalo 200626 | Finland | 70-year-old people (excluded all diabetes) | 1032 (52%) | 70 | 9.6 (not reported) | 12% | IGT | Ischaemic stroke | Sex, previous stroke or TIA, atrial fibrillation, history of MI, HF, poorly controlled hypertension (SBP ≥160 mm Hg or DBP ≥95 mm Hg), current smoking, acetylsalicylic acid use, normal memory | Not adequate |
| Kanaya 200525 | USA | Postmenopausal women with CAD (might include non-fasting glucose ≥200 mg/dL) | 2763 (100%) | 67 (44-79) | 6.8 (93.7%) | 25% | IFG 100 | All stroke and transient ischaemic attack | Age, current smoking, physical activity, alcoholic drinks/week, BMI, overall health status, use of statins, diuretics, ACEI and hormone therapy, assignment time dependent covariates, race or ethnicity, education, previous PTCA, previous CABG, sign of HF, and >1 previous MI, using baseline covariates; stratified by clinical centre | Adequate |
| Kokubo 201027 | Japan | General, excluded history of CVD (might include non-fasting glucose ≥200 mg/dL) | 5321 (53%) | 55 (30-79) | 11.7 (100%) | 28% | IFG 100 | All stroke | Age, sex, BMI, hypertension, hyperlipidaemia, and smoking and drinking status | Not adequate |
| Lezen 200628 | Europe | CAD (excluded all diabetes) | 4676 (70%) | 65 (11) | 1 (not reported) | 24% | IFG 110, IGT | All stroke | Age, sex, history of MI, HF, PVD, stroke, hyperlipidaemia, diagnosis at admission, and treatment with anti-thrombotic drugs, lipid lowering drugs, and β blockers | Not adequate |
| Liu 200729 | China | General, excluded history of CVD (might include non-fasting glucose ≥200 mg/dL) | 30 378 (47%) | 47 (35-64) | 10 (94%) | 21% | IFG 100 | Ischaemic and haemorrhagic stroke separately | Age, sex, smoking, CVD family history, and elevated total cholesterol | Not adequate |
| Oizumi 200830 | Japan | General, excluded history of stroke | 2938 (56%) | 57 (> 35) | 9.7 (not reported) | 15% | IGT | All stroke | Age, sex, hypertension | Not adequate |
| Sung 200931 | Korea | General, men (might include non-fasting glucose ≥200 mg/dL) | 652 901 (0%) | 43 (30-64) | 8.8 (not reported) | 13% | IFG 100, IFG 110 | All stroke | Age, height, smoking, alcohol consumption, regular exercise, level of monthly salary, area of residence, BP, total cholesterol, BMI | Adequate |
| Tanne 200432 | Israel | CAD (might include non-fasting glucose ≥200 mg/dL) | 13 999 (34%) | 60 (45-74) | 7 (not reported) | 30% | IFG 100, IFG 110 | Ischaemic stroke and TIA | Age, sex, BMI, hypertension, triglycerides, % HDL, and use of antiplatelets or antihypertensives. |
Adequate |
| Vermeer 200633 | Netherlands | TIA or minor stroke (might include fasting glucose ≥126 mg/dL) | 3127 (35%) | 65 (10) | 2.6 (not reported) | 5% | IGT | All stroke | Age, sex, smoking, hypertension, and minor ischaemic stroke in history | Not adequate |
| Yeboah 201134 | USA | General, excluded history of CVD (might include non-fasting glucose ≥200 mg/dL) | 6753 (47%) | 62 (45-84) | 7.5 (not reported) | 14% | IFG 100 | All stroke | Age, sex, race/ethnicity, SBP, BMI, cigarette smoking, total cholesterol, HDL-cholesterol, triglycerides, blood pressure drug use, and statin use | Adequate |
| Zhang 200835 | USA | American Indians, excluded history of stroke (excluded all diabetes) | 4507 (56%) | 60 (45-74) | 13.4 (99.8%) | NA | IFG 110 or IGT | All stroke | Age, sex, SBP, DBP, BMI, waist circumference, LDL and HDL cholesterol, triglycerides, physical activity, smoking, alcohol use, microalbuminuria, and macroalbuminuria | Adequate |
ACEI=angiotensin converting enzyme inhibitor; BP=blood pressure; BMI=body mass index; CABG=coronary artery bypass graft; CAD=coronary artery disease; CVD=cardiovascular disease; DBP=diastolic blood pressure; ECG=electrocardiogram; HDL=high density lipoprotein; HF=heart failure; IFG 100=impaired fasting glucose (fasting glucose 100-125 mg/dL); IFG 110=impaired fasting glucose (fasting glucose 110-125 mg/dL); IGT=impaired glucose tolerance (post-challenge glucose 140-199 mg/dL); MAP=mean arterial pressure; MI=myocardial infarction; NA=not available; PTCA=percutaneous transluminal coronary angiography; PVD=peripheral vascular disease; SBP=systolic blood pressure; SSF=subscapular skinfold thickness; TIA=transient ischaemic attack; TSF=triceps skinfold thickness.
*Including whether patients with diabetes may have been included because only fasting or non-fasting glucose was measured.
†Adequate adjustment denoted adjustment of at least six of seven factors: age, sex, hypertension or systolic blood pressure or antihypertensive drug, body mass index or other measure of overweight/obesity, physical activity, cholesterol concentration or statin use, and smoking.