Table 1 Baseline characteristics of study participants by incident dementia status

Age at baseline, years, mean (SD)

64.49(4.53)

56.87(8.00)

<0.001

Sex, N (%)

<0.001

 Male

2211(53.3%)

159183(44.5%)

 Female

1938(46.7%)

198762(55.5%)

Education, N (%)

<0.001

 ≥College or University degree

903(21.8%)

120477(33.7%)

 <College or University degree

1831(44.1%)

178522(49.9%)

Skin color, N (%)

<0.001

 White

3302(79.6%)

273585(76.4%)

 Colored

847(20.4%)

84352(23.6%)

Use of sun/UV protection, N (%)

<0.001

 No

625(15.1%)

33268(9.3%)

 Yes

3477(83.8%)

322624(90.1%)

 Do not go out in sunshine 3

45(1.1%)

2038(5.7%)

Employment status, N (%)

<0.001

 Yes

753(18.1%)

203004(56.7%)

 No

3396(81.9%)

154941(43.3%)

Sleep duration, hours, N (%)

<0.001

 <7

1070(25.8%)

87199(24.4%)

 7

1246(30.0%)

138878(38.8%)

 >7

1833(44.2%)

131868(36.8%)

PM_2.5, ug/m³, mean (SD)

10.04(1.05)

9.97(1.05)

<0.001

Fracture history, N (%)

0.348

 Yes

414(10.0%)

34184(9.6%)

 No

3711(90.0%)

322213(90.4%)

Vitamin D supplement, N (%)

0.092

 Yes

177(4.3%)

13490(3.8%)

 No

3944(95.7%)

343441(96.2%)

Hearing loss, N (%)

<0.001

 Yes

1440(36.1%)

90025(26.1%)

 No

2548(63.9%)

254597(73.9%)

Smoking status, N (%)

<0.001

 Never

1901 (46.1%)

194259 (54.4%)

 Previous

1805 (43.7%)

126431 (35.4%)

 Current

420 (10.2%)

36256 (10.2%)

Alcohol drinker status, N (%)

<0.001

 Never

280 (6.8%)

14058 (3.9)

 Previous

295 (7.1%)

12469 (3.5)

 Current

3566 (86.1%)

331202 (92.6)

CVD diagnosed by doctor, N (%)

<0.001

 Heart disease ^a

582(14.1%)

16708(4.7%)

 Stroke

243(5.9%)

5503(1.5%)

 Hypertension

1744(42.1%)

98880(27.7%)

TPA, MET-mins/week, mean (SD)

2423.34 (2875.69)

2449.20 (2746.68)

0.555

BMI, kg/m², mean (SD)

27.72(4.95)

27.44(4.80)

<0.001

Time spent in outdoor light, hours/day, mean (SD)

 Average

2.98(1.51)

2.51(1.45)

<0.001

 Summer

3.99(2.05)

3.46(1.97)

<0.001

 Winter

1.97(1.46)

1.57(1.31)

<0.001