Table 1.
Characteristics of studies included in the meta-analysis.
| References; cohort name; region; source; study | Age [mean (SD)], (years); female (%) | Hormone or thyroid medication users excluded | Dementia at baseline excluded | Mean follow-up (SD), years, Follow-up rate | Thyroid diseases | Outcome | Diagnosis criteria | Adjusted factors |
|---|---|---|---|---|---|---|---|---|
| Kalmijn et al. (2000); TRS; Netherlands; population; cohort | 68.8 (7.5); 72 | Yes | Yes | 9;0.85 | SHype; SHypo |
Dementia; AD | DSM-III-R (dementia), NINCDS/ADRDA (AD) | Age and gender |
| De Jong et al. (2006); TRSS; Netherland; population; cohort | 72.3 (7.4); 51 | Yes | Yes | 5.5;UC | Hype; Hypo |
Dementia; AD | DSM-III-R(dementia), NINCDS/ADRDA(AD) | Age and gender |
| Forti et al. (2012); CSBA; Italy; population; cohort | 73.3 (6.0); 53 | NO | Yes | 3.8 (0.7); 0.8 | Hypo | Dementia; AD; VaD; MCI | DSM-IV (dementia); NINCDS/ADRDA (AD; NINDS/AIREN (VaD), I-D-C (MCI) | Age, gender and education, r serum cholesterol, Geriatric Depression Scale, BMI, hypertension, diabetes, history of cardiovascular disease and plasma total homocysteine |
| Yeap et al. (2012); HIMS; Australia; population; cohort | 78.3; 0 | Yes | Yes | 5.9;0.98 | SHypo | Dementia | ICD-9 and ICD-10 | Crude |
| De Jongh et al. (2011)※; LASA; Netherland; population; cohort | 75.5;50.5 | Yes | NA | UC | SHype; SHypo |
Cognitive impairment | MMSE | Age, gender, alcohol use, smoking status, educational level, number of chronic diseases, and physical activity. |
| Aubert et al. (2017); Health ABC Study; U.S.A; population; cohort | 75.1 (2.8); 52 | Yes | Yes | 9;0.85 | SHype; SHypo |
Dementia | Dementia was defined by any of the following criteria※※ | Age, sex, race, education level and 3MS at baseline. There were 7 missing values for education level, all in participants with euthyroidism |
| George et al. (2019); ARIC; U.S.A; community; cohort | 57 (5.7);56 | NO | Yes | 21.9;0.91 | SHype; SHypo; Hype; CHypo; Hype; Hypo |
Dementia | ICD-9 | Age, sex, race-center, APOE ε4, income and education. BMI, smoking status, hypertension, diabetes, drinking status, HDL cholesterol and total cholesterol, prevalent CVD and baseline thyroid medication use. |
| Folkestad et al. (2020); DNPR, OPENTHYRO; Denmark; Registry; nested case-control | 60, 62.5; NC, 77 | Yes | Yes | 7.2,7.3; near100% | Hype; Hype, |
Dementia; AD; VaD | ICD-10 | Crude |
| Vadiveloo et al. (2011); TEARS;U.K; population; cohort | 66.5 (15.9), 77 | Yes | NC | 5.6 | SHype | Dementia | ICD-9;ICD-10 | History of dementia, history of psychiatric, and age × gender interaction |
| Thvilum et al. (2021); DNPR, OPENTHYRO; Denmark; population; cohort | 56; 83 56.4; 56 | Yes | Yes | 6.2;7.2 | Hypo | Dementia; AD | ICD10 (dementia), prescription of medicine for dementia. | Charlson Comorbidity Index; crude |
| Cárdenas-Ibarra et al. (2008); NA; Mexica; Hospital; Cross-sectional | 74.8 (8.0); 69 | NC | NC | NA | Hype; Hypo |
Cognitive impairment | MMSE | Age, sex, race, smoking history, and educational attainment |
| Park et al. (2010); KLoSHA; Korean; populatio; Cross-sectional | 65.53 (11.87); 43 | Yes | Yes | NA | SHypo | AD; cognitive impairment | Consortium to Establish a Registry for Alzheimer's Disease (CERAD), MMSE | Age, sex and duration of education |
| Parsaik et al. (2014); NA; U.S.A; population; Cross-sectional | 80.34;48.6 | Yes | Yes | NA | Hypo; SHypo; CHypo |
Mild cognitive impairment | CDR, FAQ, DSM-IV | Age, gender, education, education years, sex, ApoE ε 4, depression, diabetes, hypertension, stroke, BMI and coronary artery disease) |
| Benseñor et al. (2010); SPAH; Brazil; population; Cross-sectional | 75.63;60.5 | Yes | NC | NA | SHype; | Dementia, AD; VaD | DSM-IV | Age |
| Bajaj et al. (2014); NA; India; Hospital; Cross-sectional | 75; 57.8 | Yes | Yes | NA | SHypo | Cognitive impairment | MMSE | Age, sex and education |
Health ABC Study: the Health, Aging and Body Composition Study; ARIC, Atherosclerosis Risk in Communities Neurocognitive Study; TRS, the Rotterdam Study; TRSS, the Rotterdam Scan Study; TEARS, The Thyroid Epidemiology, Audit, and Research Study; CSBA, the Conselice Study of Brain Aging; DNPR, Danish National Patient Registry; OPENTHYRO, Odense Patient data Explorative Network Thyroid Status and Register Outcomes; TEARS, The Thyroid Epidemiology, Audit, and Research Study; LASA, the Longitudinal Aging Study Amsterdam; SPAH, the Sáo Paulo Aging and Health Study; HIMS, Health in Men Study; AD, Alzheimer's disease; VaD, Vascular dementia; MCI, Mild cognitive impairment; Hype: hyperthyroidism; Hypo, hypothyroidism; SHype, Subclinical hyperthyroidism; SHypo, Subclinical hypothyroidism; CHype, clinical hyperthyroidism; CHypo, clinical hypothyroidism; NA, Not Applicable; UC, unclear.
※: In Baseline data. UC, unclear.
※※: Dementia was defined by any of the following criteria: (i) ≧ 1.5 SD race- stratified 3MS decline from Year 1 visit to last available examination; (ii) dementia as primary or secondary diagnosis of admission on hospital records with 3MS ≦ 90 points at Year 3 or either follow- up; (iii) prescription of dementia drug recorded on the yearly drug inventory.