. 2023 Sep 25;20(1):563–592. doi: 10.1002/alz.13458

TABLE 2.

Descriptive summary of included studies.

Author, year	Title	Study design	Indigenous population	Age; mean/median age (SD)	Outcomes of interest	Risk or protective factors	Genetic or biomarker	QA
Asia
Pu'un et al., 2014 ¹⁸	Dementia among elderly Melanau: A community survey of an Indigenous people in East Malaysia	Cross‐sectional	Melanau of Malaysia N = 344	≥60 years; median 70.4 (±6.7)	Dementia	Dementia was associated with age (OR 1.19 ^a , 95% CI 1.12–1.27), no education (OR 7.56 ^a 95%CI 1.70–33.57) and multiple cardiovascular illnesses (OR 3.76 ^a , 95% CI 1.25–11.28).		Fair
Huang et al., 2016 ¹⁹	Lower prevalence of Alzheimer's disease among Tibetans: Association with religious and genetic factors	Cross‐sectional	Tibetans living in the Qinghai‐Tibet plateau N = 3974	>60 years	AD	Age groups 75−79 (OR 4.04, 95% CI 1.27–12.80), 80−84 (OR 3.58, 95% CI 0.96–13.35), ≥85 (OR 35.73, 95% CI 9.64–132.42), eating beef (OR 6.17, 95% CI 2.46–15.49), and head trauma (OR 44.62, 95% CI 2.55–782.17) were associated with AD. Kowtow (0.11, 95% CI 0.027–0.44), turning prayer beads (0.20, 95% CI 0.084–0.47), and eating chicken (OR 0.05, 95% CI 0.005–0.52) were negatively associated with AD.	CLU genotypes AA+GA of rs2279590 were associated with AD (OR 4.48, 95% CI 1.07–18.79). Genotypes GG+GC of rs9331888 (OR 0.18, 95% CI 0.038–0.89) and kowtow (OR 0.20, 95% CI 0.046–0.89) were negatively associated with AD. There was no difference in the distribution of APOE alleles between those with and without dementia.	Good
Chen et al., 2020 ²⁰	The association between neprilysin gene polymorphisms and Alzheimer's disease in Tibetan populations	Case‐ control	Tibetans N = 212	≥50 years; Mean 68.4 years (±8.3) for AD cohort	AD	No significant difference in gender, age (matched), history of hypertension and T2DM between AD and control groups.	No significant correlation between six polymorphisms of NEP gene loci (rs9829757, rs1816558, rs6776185, rs3736187, rs701109, rs989692) and AD. Allele C of NEP gene locus (rs701109) and allele T of gene locus (rs3736187) were associated with males with AD (p < 0.05). APOE ε4 was not detected in either cases or control groups.	Fair
Australia & Oceania
Smith et al., 2010 ²²	Factors associated with dementia in Aboriginal Australians	Cross‐sectional	Aboriginal Australians N = 363	≥ 45 years; mean 60.9 (±11.9)	Dementia	Older age, male gender (OR 3.1, 95% CI 1.4‐6.8), no formal education (OR 2.7, 95% CI 1.1‐6.7), current smoking (OR ^a 4.5, 95% CI 1.1‐18.6), previous stroke (OR ^a 17.9, 95% CI 5.9‐49.7), epilepsy (OR ^a 33.5, 95% CI 4.8‐232.3), head injury (OR ^a 4.0, 95% CI 1.7‐9.4), poor mobility (OR 13.4 ^a , 95% CI 4.1‐43.9), daytime incontinence (OR 116.8 ^a , 95% CI 21.9‐622.8), incontinence at night (OR 87.4 ^a , 95% CI 18.4‐415.7), any urinary problems including urinary tract infections, incontinence (OR 4.2 ^a , 95% CI 1.8‐10.2) and falls (OR 2.7 ^a , 95% CI 1.2‐6.1) was associated with dementia.	N/A	Good
LoGiudice et al., 2016 ²⁷	Incidence and predictors of cognitive impairment and dementia in Aboriginal Australians: A follow‐up study of 5 years	Longitudinal cohort	Aboriginal peoples in Australia N = 189	≥ 45 years Mean 65.4 (±10.3)	Dementia; MCI	Factors associated with CIND or dementia were age (OR 1.12 ^a , 95% CI 1.06−1.17), poor mobility (OR 3.08 ^a , 95% CI 1.09, 8.72), head injury (OR 5.22 ^a , 95% CI 1.85−14.70), analgesic medication (OR 3.60 ^a , 95% CI 1.35−9.62), and BMI (OR 0.90 ^a , 95%CI 0.82−0.98). ***** Factors associated with incident MCI or dementia from normal were stroke (OR 9.54 ^a , 95% CI 2.39‐38.13), head injury (OR 3.74 ^a , 95% CI 1.14‐12.24), analgesic medication (OR13.48 ^a , 95% CI 3.16‐57.44), BMI (OR 0.90 ^a , 95% CI 0.81‐1.00) and higher SBP (OR 1.03 ^a , 95% CI 1.00‐1.06).	N/A	Good
Radford et al., 2017 ²⁸	Childhood stress and adversity is associated with late‐life dementia in Aboriginal Australians	Cross‐sectional	Aboriginal and Torres Strait Islander people of Australia N = 296	≥60 years; median 66.6 (±6.3)	Dementia; AD	Each standard deviation increase in CTQ scores were associated with all‐cause dementia (OR 1.70, 95% CI 1.14−2.54) and AD (OR 1.77, 95% CI 1.08−2.91). CTQ scores and dementia remained significant after controlling for depression and anxiety variables (OR 1.61 ^a , 95% CI 1.05−2.45). There were no significant associations between CTQ scores and smoking, alcohol abuse, diabetes, or cardiovascular risk factors.	N/A	Good
Radford et al., 2019 ²⁹	Factors associated with the high prevalence of dementia in older Aboriginal Australians	Cross‐sectional	Aboriginal and Torres Strait Islander people of Australia N = 336	≥60 years; median 66.6 (±6.3)	Dementia; AD; MCI	Factors associated with all‐cause dementia included age (OR 2.88 ^a , 95% CI 1.93−4.31), childhood trauma (OR 1.59 ^a , 95% CI 1.06−2.40), unskilled work (OR 2.41 ^a , 95% CI 1.12−5.19), stroke (OR 3.35 ^a , 95% CI 1.57−7.15), head injury with loss of consciousness (OR 0.58 ^a , 95% CI 1.20−5.56), epilepsy (OR 3.17 ^a , 95% CI 0.88−11.49), high risk current alcohol use (OR 3.23 ^a , 95% CI 1.17‐8.93), depression (OR 1.60 ^a , 95% CI 1.08‐2.37), low BMI (OR 3.44, 95% CI 1.38‐8.61), mobility impairment (OR 2.40, 95% CI 1.20‐4.80), ADL impairment (OR 3.98 ^a ,	N/A	Good
						95% CI 2.66‐5.96), incontinence (OR 5.56, 95% CI 2.63−11.76, hospitalization in the past year (OR 2.09 ^a , 95% CI 1.06‐4.14), residing in residential care (47.72, 95% CI 9.76−233.34), living alone (OR 2.13 ^a , 95% CI 1.03‐4.43) and loneliness (OR 3.86 ^a , 95% CI 1.70‐8.75. Mild physical activity (OR 0.34 ^a 95% CI 0.14‐0.79), moderate physical activity (OR 0.44 ^a 95% CI 0.19‐0.99 and social activities (OR 0.41 ^a 95% CI 0.27‐0.62) were associated with a lower odds of dementia. ***** Age (OR 3.31 ^a 95% 2.01‐5.46), childhood trauma (OR 1.90 ^a , 95% CI 1.15‐3.16) and stroke (OR 3.08, 95% CI 1.21‐7.88) were significant independent factors associated with probable or possible AD. Lifetime low risk alcohol consumption was associated with a lower likelihood of AD relative to abstinence (OR 0.22 ^a , 95% CI 0.05‐1.00).
Derrig et al., 2020 ³⁰	Mild cognitive impairment in Aboriginal Australians	Cross‐sectional	Aboriginal and Torres Strait Islander peoples of Australia N = 287	≥60 years; Mean 65.9 years (±5.6)	aMCI; non‐aMCI	aMCI was associated with older age (OR 1.68 ^a , 95% CI 1.12‐2.53), head injury (OR 3.19 ^a , 95% CI 1.35‐7.56), symptoms of depression (OR 1.5 ^a 2, 95% CI: 1.04‐2.24), and lower blood pressure (OR 0.53 ^a , 95% CI: 0.33‐0.86). naMCI was associated with low education (OR = 4.46 ^a , 95% CI: 1.53 to 13.05), unskilled work history (OR ^a = 5.62, 95% CI: 2.07 to 13.90), higher body mass index (OR = 1.99 ^a , 95% CI: 1.30 to 3.04), and moderate to severe hearing loss (OR = 2.82 ^a , 95% CI: 1.06 to 7.55).	N/A	Good
Ma'u et al., 2021 ³²	Differences in the potential for dementia prevention between major ethnic groups within one country: A cross sectional analysis of population attributable fraction of potentially modifiable risk factors in New Zealand	Cross‐sectional	Māori people of New Zealand N = 1286	N/A	Dementia	The total weighted PAF for dementia was 51.4% for Maori people. PAF contributions for 12 risk factors were: obesity (7.3%), hearing loss (6.5%), education (5.6%), social isolation (5.1%), hypertension (5.0%), physical inactivity (5.0%), traumatic brain injury (3.5%), smoking (4.3%), depression (4.2%), diabetes (2.4%), air pollution (1.8%), alcohol (0.7%).	N/A	Good
Russell et al., 2022 ³³	Factors associated with the increased risk of dementia found in the Torres Strait	Cross‐sectional	Aboriginal and Torres Strait Islander peoples of Australia N = 274	≥45 years; Mean 65.1 years (±10.8)	Dementia	Age (OR 1.14 ^a , 95% CI 1.09‐1.20), chronic kidney disease (OR 2.77 ^a , 95% CI 1.11‐6.91), cerebrovascular disease (OR = 32.47, 95% CI 8.99‐117.31), higher ICIQ score (OR 1.23 ^a , 95% CI 1.01‐1.49) were associated with all‐cause dementia (p < 0.05). Lower education, poor mobility, hearing impairment, diabetes, dyslipidaemia and pain and falls screening test scores were associated with dementia in univariate analyses but effects were attenuated in multivariable models.		Good
Thompson et al., 2022 ³⁴	Using health check data to understand risks for dementia and cognitive impairment among Torres Strait Islander and Aboriginal peoples in Northern Queensland—A data linkage study	Cohort	Torres Strait Islander and Aboriginal population in Australia	Mean 48.9 (±10.8) years	Dementia; CIND	Increasing age was significantly associated with CIND and Dementia. Education beyond primary school (secondary or further education (RR = 0.38, 95% CI 0.19−0.76) and moderate physical activity of ≥20 min for ≥5 days in the previous 7 days by self‐reports (RR = 0.26, 95% CI 0.13−0.52) were significant as possible protective factors associated with CIND and dementia.	N/A	Good
						Albuminuria, with or without comorbid hypertension, was associated with later risk of CIND and Dementia but did not reach statistical significance, after adjusting for age. Other vascular risk measures including hypertension, diabetes, hyperglycaemia triglycerides, waist circumference, BMI showed inconclusive or had unexpected associations (lower waist circumference and lower triglycerides) with later CIND and dementia risk.
Lavrencic et al., 2022 ³⁵	Dementia incidence, APOE genotype, and risk factors for cognitive decline in aboriginal Australians: A longitudinal cohort study	Longitudinal cohort	Aboriginal and Torres Strait Islander peoples in Australia N = 155	≥60 years; mean 65.7 (±5.7)	Dementia; MCI	Risk factors associated with incident MCI or dementia include older age (OR 2.29 ^a , 95% CI 1.42‐3.70), male sex (OR 4.14 ^a , 95% CI 0.60‐10.70), unskilled work history (OR 5.09 ^a , 95% CI 1.95‐13.26), polypharmacy (OR 3.11 ^a , 95% CI 1.17‐8.28) and past smoking (OR ^a 0.24, 95% CI 0.08‐0.75). Hearing loss, lower education and vision problems were strong risk factors in bivariate models, but effects were attenuated in multivariable models. Protective factors include years of education and being an ex‐smoker (vs. never smoked).	APOE ε4 allele frequency was 24%. Homozygous or heterozygous APOE ε4 was associated with incident MCI/dementia (OR 3.96, 95% CI 1.25‐12.50).	Good
North America
Rosenberg et al., 1996 ³⁷	Genetic factors for the development of Alzheimer disease in the Cherokee Indian	Case‐control	Cherokee Indians	>65	AD	N/A	There is an inverse relationship between degree of genetic Cherokee Indian ancestry and representation of AD, independent of APOE ε4 allele status. This relationship diminished with increasing age. For a decrease of 10% in Cherokee ancestry, the odds of developing AD are estimated to be nine times greater at age 65 years but only 1.34 times greater at age 80 years.	Poor
Henderson et al., 2002 ³⁸	Apolipoprotein E4 and tau allele frequencies among Choctaw Indians	Case‐control	Choctaw Indians from the USA N = 821	mean 75 years for Dementia APOE cohort	Dementia		Lower prevalence of APOE ε4 in the Choctaw population compared to Caucasian comparators. Among those who identify > 1/2 Choctaw ancestry the ε4 allele frequency was 6%, about half that of Caucasians. In those with less than or equal to ½ Choctaw ancestry, there was evidence of an association between the APOE ε4 genotype and disease (p < 0.05) that was consistent with the degree of association seen in Caucasians. Low prevalence of the tau H2 genotype of 6% (1/5^th of Caucasian population) but statistical significance limited by low numbers of individuals with dementia.	Poor
Borenstein et al., 2007 ³⁹	Cycad exposure and risk of dementia, MCI, and PDC in the Chamorro population of Guam	Cross‐sectional	Chamorros on Guam N = 1984	≥65 years; Mean 79 years (±7.0) for GD cohort	GD; MCI	Picking (OR 1.42 ^a , 95% CI 1.05‐1.91), processing (OR 1.57 ^a , 95% CI 1.19−2.06) and eating (OR 1.42 ^a , 95% CI 1.13‐1.79) fadang in young adulthood were associated with GD. Picking fadang OR 2.87 (95% CI 1.48‐5.56) and eating fadang as a young adult OR 2.18 (95% CI 1.34‐3.55) were associated with PDC. PARPs for GD for picking 0.13 (95% CI 0.03‐0.22), processing 0.12 (95% CI 0.03‐0.22), and eating fadang 0.22 (95% CI 0.07‐0.38). Associations among men were more consistently significant across all outcome groups compared with women in subanalyses by sex. Consumption of fruit bats or exposure to cycad used as a topical medicine were not significant for any of the outcomes. ***** Picking (OR 1.84 ^a , 95% CI 1.32‐2.57), processing (OR 1.83 ^a , 95% CI 1.34‐2.49), and eating (OR 1.84 ^a , 95% CI 1.39‐2.43) fadang in young adulthood were associated with MCI. PAR proportions for MCI for picking 0.26 (95% CI 0.12‐0.40), processing 0.23 (95% CI 0.09‐0.38), and eating fadang 0.28 (95% CI 0.07‐0.50).	APOE ε4 cases varied minimally across case groups or controls and was not statistically significant.	Good
Sundar et al., 2007 ⁴⁰	Two sites in the MAPT region confer genetic risk for Guam ALS/PDC and dementia	Case‐control	Chamorros on Guam N = 600	Mean 74.9 (±7.2) years for GD cohort	GD	N/A	MAPT gene SNP 2 (OR 1.61, 95% CI 1.00−2.62), SNP 9 (OR 1.06, 95% CI 0.57−1.97) and SNP 6 and 9 (OR 3.02, 95% CI 1.10−8.25) were associated with GD. No significant evidence of an association was found between APOE and GD.	Fair
Galasko et al., 2007 ⁴¹	Prevalence of dementia in Chamorros on Guam: Relationship to age, gender, education, and APOE	Cross‐sectional	Chamorros on Guam N = 2029	≥65 years; mean 73.8 (±6.0)	GD; MCI	Age (OR 1.11, 95% CI 1.08–1.13) and low education (OR 0.87, 95% CI 0.84–0.90) were associated with dementia. Gender was not significantly associated with dementia or GD after adjusting for age and education. ***** MCI participants (77.4 ± 6.3 years) were older than cognitively normal participants (72.8 ± 5.2 years) with greater ratio of women to men.	APOE ε4 frequency was 5.3% for those with all‐cause dementia compared to 4.0% for unaffected controls. APOE ε4 was not significantly associated with all‐cause dementia, GD, PDC or vascular dementia.	Good
Weiner et al., 2008 ⁴³	Atherosclerosis risk factors in American Indians with Alzheimer disease: Preliminary findings	Case‐control	American Indians from the United States N = 68	Median 78 (range 56‐91) years for AD cases	AD	There is an association between history of hypertension and diabetes and AD in a small sample of American Indians. A high percentage of Choctaw cases and controls had a history of hypertension compared to white participants. History of diabetes was most prevalent in Indian ADs; less so in Indian controls and White participants with AD. Age, education, waist size, BMI, history of high cholesterol, history of myocardial infarction or history of stroke did not differ significantly between the three groups.	Plasma homocysteine concentrations increased with age (p < 0.001) but was not significantly associated with degree of Indian heritage (p = 0.63); sex (p = 0.14) or AD (p = 0.14).	Fair
Weiner et al. 2009 ⁴⁴	Brain MRI, apolipoprotein E genotype, and plasma homocysteine in American Indian Alzheimer disease patients and Indian controls	Case‐control	American Indians from the United States N = 21	>60 years	AD	No statistically significant differences between AD subjects and controls in age, gender, degree of Indian heritage, history of hypertension, diabetes, high cholesterol, waist circumference or BMI. Education was lower in the AD group but this was not statistically significant.	More AD subjects had APOE ε4 alleles than controls (p = 0.043) but there was no significant relationship between the presence of an APOEε4 allele and Indian heritage in the AD group or in the combined AD and control groups. Median plasma homocysteine concentrations were higher in AD subjects but did not achieve statistical significance. There were no significant differences in neuroimaging findings between the two groups, but AD subjects had greater volume of WMH and greater WMHV/WBV ratio (median 1.63% vs. 0.65%) and a far greater range of WMHV. In those with AD, WBV correlated with BMI (p = 0.015) and age (p = 0.005).	Fair
Weiner et al., 2011 ⁴⁵	The relationship of cardiovascular risk factors to Alzheimer disease in Choctaw Indians	Case‐control	American Indians from the United States N = 78	Median 78 years (range 54‐91) years for AD cases	AD	There were no significant differences between Choctaws with and without AD in gender, number or types of cardiovascular risk factors (history of hypertension, diabetes, high cholesterol and myocardial infarction). Indian AD groups had a significantly higher percentage of affected first‐degree relatives than the Indian controls.	Choctaw groups with and without AD had lower proportion of one or more APOE ε4 alleles than White participants. There was a significant relationship between homocysteine concentration and onset age for American Indians with AD (p = 0.005).	Fair
MacDonald et al., 2015 ⁴⁷	Implications of risk factors for Alzheimer's disease in Canada's Indigenous population	Cohort	Indigenous peoples of Canada (First Nation, Inuit, Metis)	N/A	Dementia	Physical inactivity (32.5%, 95% CI 10.1%−51.1%), low educational attainment (22.4%, 95% CI 14.6%−29.6%), smoking (19.4%, 95% CI 5.8%−32.9%), midlife obesity (16.8%, 95% CI 10.3‐23.6), midlife hypertension (14.2%, 95% CI 4.2%−25.1%) and diabetes mellitus (6.0%, 95% CI 2.6%−9.7%) contribute to dementia rates in the Indigenous population. The combined PAR for AD for all six modifiable risk factors was 79.6% among on‐reserve Indigenous, 74.9% among off‐reserve Indigenous, and 67.1% among non‐Indigenous peoples in Canada.	N/A	Good
Carty et al. 2020 ⁵⁰	Risk factors for Alzheimer's disease and related Dementia diagnoses in American Indians	Cohort	American Indians N = 3464	≥55 years	Dementia	Age (RR 1.12 ^a 95% CI 1.11‐1.14), hypertension (RR 2.75 ^a 95% CI 1.75‐4.31), depression (RR 2.49 ^a 95% CI 1.79‐3.46), hyperlipidaemia (RR 1.41 ^a 95% CI 1.08‐1.84) and diabetes (RR 2.07 ^a 95% CI 1.41‐3.03) were associated with increased risk of a dementia diagnosis. Female sex (RR 0.70 ^a 95% CI 0.52‐0.94), being married/having a life partner (RR 0.67 ^a 95% CI 0.48‐0.94) were associated with lower risk of a dementia diagnosis.		Fair
Smith M et al., 2021 ⁵¹	Disparities in Alzheimer disease and mild cognitive impairment among Native Hawaiians and Pacific Islanders	Cohort	Native Hawaiians & Pacific Islanders N = 87	N/A	AD; MCI	The mean age of Native Hawaiians and Pacific Islanders at time of diagnosis with AD or MCI was 73.2 (±12.5) years. Mean age at diagnosis was lower in this group with greater percentage with a diagnosis <65 years compared to other racial groups (p = 0.02). There was a higher proportion of women than men with diagnosis of AD over MCI 67%, p = .028). Hypertension, hyperlipidaemia, and type II diabetes were found to be higher among the Native Hawaiians and Pacific Islanders (hypertension 74%, p = 0.012; hyperlipidemia 70%, p =0 .05; T2DM 28%, p = 0.002). There were no statistically significant differences in marital status, insurance and number of comorbidities between the different racial groups.		Fair
Suchy‐Dicey et al., 2021 ⁵²	APOE genotype, hippocampus, and cognitive markers of Alzheimer's disease in American Indians: Data from the Strong Heart Study	Cohort	American Indians N = 811	≥64 years Mean 73.1 (±6.0)	Cognitive impairment ^b		APOE ε4 carrier frequencies were 4/3 21.0%; ε4/4 0.7%; ε4/2 0.6% (total 22.3%). Non‐APOE ε4 carrier frequencies include ε3/3 72.5%; ε3/2 5.1%; ε2/2 0%. Sociodemographic and clinical features were similar between APOE ε4 carriers and non‐carriers apart from higher proportion with LDL and chronic kidney disease (not significant). MRI‐defined brain volumes (brain, hippocampal, intracranial volumes) and multidomain cognitive test scores were similar between APOE ε4 carriers and non‐carriers and not significantly associated with carrier status, after adjusting for sociodemographic and clinical conditions.	Good
South America
Marca Ysabel 2021 ⁵⁵	Dissecting the role of Amerindian genetic ancestry and the APOE ε4 allele on Alzheimer disease in an admixed Peruvian population	Case‐control	Peruvian N = 207	≥65 years	AD	N/A	Genetic ancestry surrounding the APOE is predominately Amerindian (60.6%). APOE ε4 allele frequency was 9.2% in cognitively impaired individuals versus 4.6% in those cognitively normal and significantly associated with increased risk of AD (OR 5.02 ^a , 95% CI 2.3−12.5)	Fair
Gatz et al., 2022 ⁵⁶	Prevalence of dementia and mild cognitive impairment in Indigenous Bolivian forger‐horticulturalist	Cohort	Indigenous Tsimane and Moseten people of Bolivia N = 623	≥60 years	Dementia; MCI	Dementia cases were equal between women and men. *** MCI was more prevalent among women compared to men (p = 0.02 for sex difference). *** Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms and gait abnormalities.	The number of APOE ε4 alleles did not distinguish between those with cognitive impairment and those without however, carrying two (vs. none) alleles was associated with significantly greater odds of cognitive impairment (Tsimane OR 10.7 95% CI 1.47, 78.6; Moseten OR 11.5 95% CI 1.28‐102.8). On CT, medial temporal atrophy (OR 8.89 95% CI 1.85‐42.9), internal carotid artery calcification morphology (OR 6.10 95% CI 1.23‐30.4), basal ganglia calcification (OR 5.27 95% CI 1.85‐∞), calcification of the lenticulostriate arteries (OR 4.77 95% CI 1.04‐22.0) and lenticulostriate arteries calcification density (OR 1.11 95% CI 1.01‐1.23) was associated with cognitive impairment for Tsimane but not for Moseten. Poorer cognition was associated with severity of intracranial vascular calcification, greater severity of cerebral atrophy, especially of white matter volume.	Good

Abbreviations: AD, Alzheimer's dementia; aMCI, amnestic mild cognitive impairment; APOE4, apolipoprotein E allele; BMI, body mass index; CIND, cognitive impairment not dementia; CLU, clusterin; CT, computed tomography; CTQ, Childhood Trauma Questionnaire; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; Fhx dementia, family history of dementia; GD, Guam dementia; ICIQ, International Consultation on Incontinence Questionnaire; MAPT, microtubule‐associated protein tau; MCI, mild cognitive impairment; MRI, magnetic resonance imaging; NEP, neprilysin; OR, odds ratio; PAF, population attributable fractions; PAR, population attributable risk; PDC, parkinsonism dementia complex; PTSD, post‐traumatic stress disorder; QA, quality assessment; RICE, Retrospective Indigenous Childhood Enrichment Scale; RR, relative risk; SBP, systolic blood pressure; T2DM, type 2 diabetes mellitus; WHMH, white matter hyperintensities; WHV, white matter hyperintensities volume.

^{^a}

Adjusted/multivariate model.

^{^b}

Cognitive impairment was defined as deficits (1.5 SD below mean) in leaning and retention tasks in multidomain psychometric tests such as the California Verbal Learning Test, Weschler Adult Intelligence Scale, Controlled Oral Word Association, and Modified Mini Mental Status Examination.