Table 1.
Characteristics of all included studies
| Study author, publication year | Region (data source) | Ethnicity | Study design | Setting | Analytic sample size | % Female | Mean baseline age in years (SD) | Mean follow-up length in years (SD) | Exposure: MetS criteria | Outcomes Reported | Outcome Assessment |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Creavin et al., 2012 [14] | UK (CaPS) | NR | Research Cohort | Community | N = 1,131 | 0.0% | 57.7 (53.6–61.4)§§*** | Up to 21*** | NCEP-ATP III | All-cause dementia | Adjudicated based on DSM-IV, NINCDS-ADRDA, NINDS-AIREN |
| Exalto et al., 2015 [6] | Netherlands (ADC) | NR | Research Cohort | Memory clinic | N = 59 | 39.5%# | 66.7 (9.7)# | 3.4 (1.1) | NCEP-ATP III revised AHA/NHLBI | All-cause dementia | NR |
| Fan et al., 2017 [7] | Taiwan (TwSHHH) | 100% Asian [30] | Research Cohort | Community | N = 3,458 | 53.0% | 54.5 (10.7)† | 9.2|| | NCEP-ATP III revised AHA/NHLBI | All-cause dementia | Medical records, ICD-9-CM: 290.0, 290.1x, 290.2x, 290.3, 290.4x, 294.1, 331.0, 331.1, 331.2 |
| Forti et al., 2010 [8] | Italy (CSBA) | NR | Research Cohort | Community |
Age < 75 years: N = 466 Age ≥ 75 years: N = 283 |
Age < 75 years: 51.3% Age ≥ 75 years: 56.9% |
Age < 75 years: 69.3 (3.0)† Age ≥ 75 years: 79.8 (3.8)† |
3.9 (0.8) | NCEP-ATP III |
All-cause dementia AD VaD |
Adjudicated based on DSM-IV, NINCDS-ADRDA, NINDS-AIREN [31] |
| Lee et al., 2020 [9] | South Korea (KNHI) | 100% Asian [32] | Medical Records Cohort | Community | N = 4,106,590 | 45.5% | 55.8 (10.1) | 4.9 (NR) | Harmonized Criteria |
All-cause dementia AD VaD |
Neuropsychological exam, antidementia drug prescriptions, and medical records (ICD-10: AD [F00 or G30], VD [F01], or other dementia [F02, F03, G23.1 or G31]) |
| Ng et al., 2016 [11] | Singapore (SLAS) | 100% Asian | Research Cohort | Community | N = 1,936 | 64.8%* | 64.9 (6.8)* | 3.8 (NR) §§ | IDF | All-cause dementia | Adjudicated based on DSM-IV |
| Muller et al., 2007 [10] | USA (Medicare – Manhattan) |
29.9% White 30.8% African American 39.3% Hispanic |
Medical Records Cohort | Community | N = 1,833 | 67.3% | 76.1 (6.0) | 4.4 (2.5) | NCEP-ATP III |
All-cause dementia AD VaD |
Adjudicated based on DSM-IV, CDR ≥1, NINCDS-ADRDA |
| Peng et al., 2018 [29] | China (Multicentre study) | 100% Asian | Research Cohort | Community | N = 787 | 43.1% | 67.1 (7.2) | 5 (NR) | NCEP-ATP III | PDD | Adjudicated based on Movement Disorder Task Force (2007) criteria## |
| Raffaitin et al., 2009 [12] | France (3 C Study) | NR | Research Cohort | Community | N = 7,077 | 61%†† | 73.4 (4.9)†† | Up to 4 (NR) | NCEP-ATP III |
All-cause dementia AD VaD |
Adjudicated based on DSM-IV, NINCDS-ADRDA, Hachinski score, MRI, history of vascular disease |
| Solfrizzi et al., 2010 [13] | Italy (ILSA) | NR | Research Cohort | Community | N = 2,097 | 47.3% | 72.9 (5.6) | Up to 3.5 (NR) | NCEP-ATP III |
All-cause dementia AD VaD Other dementias^# |
Adjudicated based on DSM-III-R, NINCDS-ADRDA, and ICD-10 |
| Machado-Fragua et al., 2022 [16] | UK (Whitehall II) |
Age < 60: White: 90.1% Non-white: 9.9% Age 60–69: White:91.6% Non-white: 8.4% Age ≥ 70: White: 90.3% Non-white: 9.7% |
Research Cohort | Community |
Age < 60: N = 7,265 Age 60–69: N = 6,660 Age ≥ 70: N = 3,608 |
Age < 60: 30.5% Age 60–69: 29.3% Age ≥ 70: 29.4% |
Age < 60: 55.1 (2.9) Age 60–69: 65.0 (1.5) Age ≥ 70: 73.9 (1.9) |
Age < 60: 19.6 (5.9) Age 60–69: 10.9 (5.8) Age ≥ 70: 5.7 (3.2) |
Harmonized Criteria | All-cause dementia | Medical records, ICD-10: F00-F03, F05.1, G30, G31 |
| Qureshi et al., 2023 [27] | UK (UK Biobank) |
White: 96.8% Non-white: 2.7% Missing: 0.5% |
Research Cohort | Community | N = 176,249 | 52.2% | 64.1 (2.9) | 11.8 (2.2) | Harmonized Criteria | All-cause dementia | Medical records, ICD-9: 331.0, 290.4, 331.1, 290.2, 290.3, 291.2, 294.1, 331.2, 331.5; ICD-10: F00, F00.0, F00.1, F00.2, F00.9, G30, G30.0, G30.1, G30.8, G30.9, F01, F01.0, F01.1, F01.2, F01.3, F01.8, F01.9, I67.3, F02.0, G31.0, A81.0, F02, F02.1, F02.2, F02.3, F02.4, F02.8, F03, F05.1, F10.6, G31.1, G31.8 |
| Qureshi et al., 2024 [28] | UK (EPIC-Norfolk) |
White: 99.7% Non-white: 0.3% |
Research Cohort | Community | N = 20,150 | 54.0% | 62.6 (7.5) | 18.8 (6.3) | Harmonized Criteria | All-cause dementia | Medical records, ICD-10: F00, G30, F00.0, G30.0, F00.1, G30.1, F00.2, G30.8, F00.9, G30.9, F01, F01.0, F01.1, F01.2, F01.8, F01.9, F02, F02.0, F02.1, F02.2, F02.3, F02.8, G31.0, G31.8, F03, F05.1, F10.7 |
| Ekram et al., 2023 [15] | Australia & USA (ASPREE trial) |
White: 91.2%$# Non-white: 8.8%$# |
Research Cohort | Community | N = 16,965 | 56.3%$# | 75.1 (4.5)$# | 4.7 (3.6–5.7)§§ & | ACC/AHA 2018 Guideline | All-cause dementia | Adjudicated based on DSM-IV |
CaPS: Caerphilly Prospective Study, ADC: Amsterdam Dementia Cohort, TwSHHH: Taiwanese Survey on Prevalence of Hypertension Hyperglycemia and Hyperlipidemia, TNHIRD: Taiwan National Health Insurance Research Database, CSBA: Conselice Study of Brain Ageing, KNHI: Korean National Health Insurance Service - National Health Information Database, SLAS: Singapore Longitudinal Ageing Study, 3C Study: Three-City study, ILSA: Italian Longitudinal Study on Ageing, MetS: Metabolic syndrome, NCEP-ATP III: National Cholesterol Education Program - Adult Treatment Panel III, AHA/NHLBI: American Heart Association and the National Heart, Lung, and Blood Institute, IDF: International Diabetes Foundation, DSM: Diagnostic and Statistical Manual of Mental Disorders, NINCDS-ADRDA: National Institute of Neurological and Communicative Disorders and Stroke - Alzheimer’s Disease and Related Disorders Association, NINDS-AIREN: National Institute of Neurological Disorders and Stroke (NINDS) and the Association Internationale pour la Recherche et l’Enseignement en Neurosciences (AIREN), NR: Not reported, ICD-9: International Classification of Diseases, Ninth Revision, ICD-10: International Classification of Diseases, Tenth Revision CDR: Clinical Dementia Rating, SD: Standard deviation, AD: Alzheimer’s disease, VaD: Vascular dementia, PDD: Parkinson’s disease dementia; EPIC: European Prospective Investigation into Cancer, ASPREE: ASPirin in Reducing Events in the Elderly, ACC/AHA: American College of Cardiology/American Heart Association Task Force Guideline
§§: Median (Interquartile Range), #: Reported for 86 participants, *: Reported for 1,519 participants (primary sample), ***: Among phase 2 participants (n=2,398) - chosen based on balance between longest follow-up and largest sample size, †: Combined mean and SD,||: Calculated based on other available data. ††: Reported for 7,087 participants, &: Additional information provided by the authors, ^#: Defined as dementia in other diseases classified elsewhere (e.g., dementia in Pick’s disease, Creutzfeldt - Jakob disease, Huntington’s disease, Parkinson’s disease, human immunodeficiency virus [HIV], or other disease); $#: Among primary sample of 18,264 participants, &: Additional information provided by the authors