Table 1. Characteristics of included studies.
| Author, country; Cohort | Follow-up years; sample size/incident case; sex, %male; age (years) | Categories of BMI (kg/m2) | Definition of metabolic status | Covariates | Type of stroke | Divide participants into 4 or 6 groups | RRs/HRs (95% CIs) | Quality score |
|---|---|---|---|---|---|---|---|---|
| Song, 2007, USA: Women’s Health Study | 8.8; 25,626/256; 0; 54.6 | Normal: <25, overweight: 25–29.9, obese: ≥30 | A metabolically healthy state was considered if ≤2 of the metabolic factors (ATPIII criterion): (I) BP ≥135/85 mmHg; (II) triglycerides ≥150 mg/dL; (III) HDL cholesterol <50 mg/dL; (IV) fasting glucose ≥110 mg/dL | Age, randomized treatment assignment in the Women's Health Study, smoking, exercise, alcohol intake, total calorie intake, postmenopausal hormone use, multivitamin use, parental history of myocardial infarction before 60 year | Stroke | MH-NW | 1 (ref) | 9 |
| MH-OW | 0.83 (0.58–1.18) | |||||||
| MHO | 1.13 (0.70–1.82) | |||||||
| MU-NW | 1.24 (0.64–2.39) | |||||||
| MU-OW | 1.74 (1.05–2.87) | |||||||
| MUO | 1.49 (0.86–2.58) | |||||||
| Hinnouho, 2015, UK: Whitehall II study | 17.4; 7,122/118; 69.7; 49.3 | Normal: <25, overweight: 25–29.9, obese: ≥30 | A metabolically healthy state was considered if none or one of the metabolic factors (ATPIII criterion): (I) SBP ≥130 mmHg or DBP ≥85 mmHg or under medical treatment; (II) triglycerides (≥1.7 mmol/L) or under medical treatment; (III) HDL cholesterol 1.04 mmol/L in men and 1.29 mmol/L in women; (IV) fasting glucose (≥5.6 mmol/L) or under medical treatment | Sex, socioeconomic status, marital status, ethnicity, physical activity, smoking, alcohol, fruits, vegetables consumption, CVD medication, procedures | One of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction, and not specified stroke and transient cerebral ischemic attacks | MH-NW | 1 (ref) | 8 |
| MH-OW | 0.59 (0.32–1.09) | |||||||
| MHO | 1.59 (0.68–3.70) | |||||||
| MU-NW | 1.82 (1.03–3.22) | |||||||
| MU-OW | 2.05 (1.29–3.26) | |||||||
| MUO | 2.15 (1.12–4.14) | |||||||
| Andersen, 2015, Denmark: Danish Medical Birth Register | 5.6; 261,489/NA; 0; 30.5 | Normal: <25, abnormal weight: ≥25 | A metabolically healthy state was considered if none of the metabolic factors: (I) hypertension: a registered diagnosis of hypertension in the National Patient Register (ICD-10 = DI10-DI15) plus at least one claimed prescription for an antihypertensive agent within 90 days, or claims of at least two separate types of antihypertensive agents within 90 days; (II) dyslipidemia: claim of a prescription for a lipid-lowering drug; (III) diabetes: either (i) two separate prescription claims of glucose-lowering agents within 6 months (classifying individuals as having diabetes from the date of the second prescription claim), or (ii) a new entry in the National Patient Register with a diagnosis of diabetes | Age, calendar year, smoking | Ischemic stroke | MH-NW | 1 (ref) | 8 |
| MHO | 0.99 (0.77–1.26) | |||||||
| MU-NW | 1.88 (1.24–2.85) | |||||||
| MUO | 1.87 (1.30–2.71) | |||||||
| Guo, 2016, USA: ARIC | 18.7; 14,685/1,044; 45.6; 54.3 | Normal: <25, overweight: 25–29.9, obese: ≥30 | A metabolically healthy state was considered if ≤2 of the metabolic factors (ATPIII criterion): (I) SBP ≥130 mmHg or DBP ≥85 mmHg; (II) untreated total cholesterol ≥240 mg/dL and HDL <40 mg/dl in men and <50 mg/dL in women; (III) untreated fasting ≥100 mg/dL or HbA1c ≥5.7% | Age, sex, race, income, education, tobacco smoking, alcohol drinking | Stroke | MH-NW | 1 (ref) | 8 |
| MH-OW | 1.31 (0.38–4.49) | |||||||
| MHO | 0.85 (0.36–2.04) | |||||||
| MU-NW | 2.45 (0.71–8.44) | |||||||
| MU-OW | 3.92 (1.19–12.94) | |||||||
| MUO | 3.87 (1.17–12.77) | |||||||
| Rishi, 2017, UK: THIN | 5.4; 3,495,777/54,705; 45.5; 43.7 | Normal: <25, overweight: 25–29.9, obese: ≥30 | A metabolically healthy state was considered if none of the metabolic factors: (I) hypertension; (II) hyperlipidemia; (III) diabetes | Age, sex, self-reported smoking status, social deprivation | One of transient ischemic attack, ischemic stroke, hemorrhagic stroke | MH-NW | 1 (ref) | 8 |
| MH-OW | 1.03 (0.98–1.07) | |||||||
| MHO | 1.16 (1.10–1.23) | |||||||
| MU-NW | 1.54 (1.50–1.58) | |||||||
| MU-OW | 1.51 (1.47–1.55) | |||||||
| MUO | 1.56 (1.52–1.60) | |||||||
| Lee, 2018, Korea: NHIS-NSC |
7.4; 354,083/4,884; 52.7; 45.8 | Normal: <25, abnormal weight: ≥25 (stage I: 25–29.9, stage II: ≥30) | A metabolically healthy state was considered if none of the metabolic factors (ATPIII criterion): (I) SBP ≥130 mmHg or DBP ≥85 mmHg or under medical treatment; (II) total cholesterol (≥240 mg/dL) or under medical treatment; (III) fasting glucose ≥110 mg/dL or under medical treatment | Age, sex, income, area, smoking, drinking, exercise, history of ischemic heart disease, peripheral artery disease, congestive heart failure, transient ischemic | Ischemic stroke | MH-NW | 1 (ref) | 8 |
| MHO | 0.99 (0.81–1.20) | |||||||
| MU-NW | 1.72 (1.55–1.90) | |||||||
| MUO | 2.06 (1.85–2.28) | |||||||
| Nathalie, 2018, USA: NHS | 24; 90,257/3,080; 0; 46.3 | Normal: <25, overweight: 25–29.9, obese: ≥30 | A metabolically healthy state was considered if none of the metabolic factors: (I) hypertension; (II) hyperlipidemia; (III) diabetes | Age, race, highest educational degree, alcohol consumption, smoking status, postmenopausal status, post-menopausal hormone use, physical examinations for screening purposes, aspirin use, family history of myocardial infarction and diabetes, and physical activity | Stroke | MH-NW | 1 (ref) | 8 |
| MH-OW | 1.29 (1.05–1.58) | |||||||
| MHO | 1.37 (1.04–1.81) | |||||||
| MU-NW | 2.22 (1.92–2.57) | |||||||
| MU-OW | 2.27 (1.97–2.63) | |||||||
| MUO | 2.58 (2.22–3.00) | |||||||
| Li, 2019, China: CHRLS | 3.6; 7,849/NA; NA; 58.8 | Normal: <24, abnormal weight: ≥24 | A metabolically healthy state was considered if none or one of the metabolic factors: (I) SBP ≥130 mmHg or DBP ≥85 mmHg or physician-diagnosed or under medical treatment; (II) triglycerides ≥150 mg/dL or under medical treatment; (III) HDL <40 mg/dL in men and <50 mg/dL in women; (IV) fasting glucose ≥100 mg/dL or doctor’s diagnosed diabetes or under medical treatment, orHbA1c ≥6.0% | Age, sex, region, marital status, education level, smoking status, frequency of alcohol consumption in the past year, physical activity | Stroke | MH-NW | 1 (ref) | 7 |
| MHO | 1.32 (0.97–1.80) | |||||||
| MU-NW | 2.12 (1.87–2.41) | |||||||
| MUO | 2.20 (1.87–2.60) |
BMI, body mass index; RR, relative risk; HR, hazard ratio; CI, confidence interval; USA, United States of America; ATPIII, Adult Treatment Panel III; UK, United Kingdom; HDL, high-density lipoprotein; MH-NW, Metabolically Healthy Normal Weight; MH-OW, Metabolically Healthy Overweight; MHO, Metabolically Healthy Obese; MU-NW, Metabolically Unhealthy Obese; MU-OW, Metabolically Unhealthy Overweight; MUO, Metabolically Unhealthy Obese; CVD, cardiovascular disease; BP: blood pressure; ARIC, Atherosclerosis Risk in Communities Study; THIN, The Health Improvement Network; NHIS-NSC, National Health Insurance Service-National Sample Cohort; NHS, Nurses’ Health Study; CHRLS, China Health and Retirement Longitudinal Study.