Table 1 Selected characteristics of American Indian participants aged 65–95 in the Strong Heart Study/cerebrovascular disease and its consequences in American Indians (CDCAI) sub-cohort, at Visit 1 (2010–2013) and Visit 2 (2017–2019)

From: Cognitive reserve is associated with education, social determinants, and cognitive outcomes among older American Indians in the Strong Heart Study

 

Visit 1: 2010–13 N = 818

Visit 2: 2017–19 N = 403

P value

Age (years)

73.0 (5.9)

78.0 (4.7)

<0.001

Female sexc, %

67.5%

70.2%

0.34

Southwest

12.0%

12.8%

0.80

Northern Plains

45.7%

43.8%

 

Southern Plains

42.3%

43.4%

 

Education

  

0.01

   Up to or some high school, %

23.9%

17.4%

 

   High school graduate or GED, %

29.9%

31.2%

 

   Some college, %

30.4%

32.9%

 

   Bachelor’s degree or more, %

15.6%

17.2%

 

Household annual income

  

0.29

   <$10,000 per year

30.5%

24.8%

 

   $10–19,000 per year

28.7%

28.5%

 

   $20–34,000 per year

21.4%

22.1%

 

   $35,000+ per year

19.3%

21.6%

 

Standard alcohol drinks per daya

3.8 (7.1)

2.0 (3.1)

0.006

Chronic kidney disease (CKD, eGFR <60 mL/min)

26.9%

51.0%

<0.001

Overweight or Obese (BMI >25)

84.7%

81.4%

0.15

Hypertension

80.8%

81.8%

0.68

CESD score

11.1 (8.7)

12.7 (8.5)

0.003

Depressed (CESD score 16+), %

24.3%

30.7%

0.02

Fasting plasma glucose mg/dL

123.8 (52.9)

122.7 (54.9)

0.74

Diabetes mellitus, %

49.5%

47.9%

0.61

APOEe4 carrier

-

20.9%

 

pTau pg/mL

-

6.3 (4.8)

 

Ab42/40 ratio

-

0.06 (0.01)

 

GFAP pg/mL

-

178.2 (96.0)

 

NfL pg/mL

-

41.0 (30.5)

 

Weschler Adult Intelligence Scale 4th ed. digit symbol coding subtest (WAIS DSST) score

44.8 (14.7)

41.9 (14.1)

0.02

Brain volume, units: % intracranial vol

67.2 (5.3)

63.0 (6.1)

<0.001

Residuals - WAIS DSST / brain volume(% IC), mean (range)b

0 (-39.1, 42.6)

0 (-37.6, 39.9)

>0.9

Controlled Oral Word Association FAS (COWA) score

24.4 (11.4)

24.3 (11.1)

0.92

White matter hypointensities (WMH), units: % intracranial vol

0.40 (0.36)

0.26 (0.27)

<0.001

Residuals - COWA / WMH volume (% IC), rangeb

20.0 (-21.5, 64.9)

15.5 (-20.0, 58.1)

<0.001

California Verbal Learning Test II Short Form long delay free recall score (CVLT LF)

5.5 (2.2)

4.7 (2.4)

<0.001

Hippocampus volume, units: % intracranial vol

0.49 (0.05)

0.48 (0.06)

<0.001

Residuals – CVLT LF / Hipp. volume(% IC), rangeb

0 (-6.6, 5.0)

0 (-5.6, 5.4)

>0.9

Modified Mini-Mental Status Examination (3MSE) score

88.5 (9.2)

87.1 (9.5)

 

Montreal Cognitive Assessment (MoCA) score

-

18.9 (4.3)

 

Animal naming test score

-

13.8 (4.5)

 

Vegetable naming test score

-

9.6 (3.3)

 

Craft Story immediate recall paraphrase score

-

10.1 (4.3)

 

Craft Story delayed recall paraphrase score

-

8.8 (4.4)

 

Benson Complex Figure copy score

-

15.6 (1.7)

 

Benson Complex Figure recall score

-

8.8 (3.7)

 

Number Span Test forward score

-

6.5 (2.3)

 

Number Span Test backward score

-

4.5 (1.9)

 

Trail Making Test A seconds

-

65.4 (32.1)

 

Trail Making Test B seconds

-

169.4 (79.2)

 

Multilingual Naming Test (MINT) score

-

27.2 (3.2)

 

Composite cognitive score (averaged Z-scores), range

−3.4, 1.7

−1.8, 1.1

 
  1. aAlcohol standard drinks per day mean (SD) tabulated among users: Visit 1 n = 143 (17.5%), Visit 2 n = 66 (16.4%).
  2. bCalculation of residual metrics using multiple variables with partial missingness resulted in slightly smaller numbers for these metrics of cognitive reserve: WAIS-Brain Visit 1 n = 765 and Visit 2 n = 298, COWA-WMH Visit 1 n = 765 and Visit 2 n = 298, CVLT-Hipp Visit 1 n = 744 and Visit 2 n = 289.
  3. cCategorization of participants with self-identified male sex is mutually exclusive to those with female sex, per data collection methods and data completeness: % male at Visit 1 was 32.5% and at Visit 2 was 29.8%.
  4. P value calculated based on ANOVA, Wilcoxon rank-sum, or T-test. Cognitive reserve operationalized as residuals of observed-over-expected performance in WAIS digit symbol test regressed over the degree of brain atrophy standardized to intracranial volume (adjusted for age and sex). Diabetes mellitus is categorized based on high fasting plasma glucose, prior diagnosis, or use of antihyperglycemics or insulin. Values are given as mean (SD) unless otherwise noted. Composite cognitive score is defined as the mean of Z-scores for all cognitive tests collected at each exam (Methods).
  5. Terms defined: Weschler Adult Intelligence Scale Digit Symbol Coding Test (WAIS DSST) over brain volume as percent intracranial volume (WAIS-Brain), (middle) residuals of Controlled Oral Word Association f/a/s test (COWA) over white matter hypointensities volume (MRI T1 sequence) as percent intracranial volume (COWA-WMH), and (bottom) residuals of California Verbal Learning Test version II short form long delay free recall test (CVLT LF) over hippocampus volume as percent intracranial volume (CVLT-Hipp). Body mass index (BMI), Centers for Epidemiologic Studies Depression Scale (CESD), Apolipoprotein E (APOE), phosphorylated tau (pTau), amyloid beta 42/40 ratio (Ab42/40), glial fibrillary atrial protein (GFAP), neurofilament light chain (NfL).
Back to article page