Table 1 Demographic and clinical characteristics of cognitively normal participants by the categories of serum zinc

N

241

70

80

91

Age, y

69.73 (8.00)

70.14 (7.13)

71.04 (8.41)

68.26 (8.11)

0.067^a

Female, n (%)

114 (47.30)

36 (51.43)

39 (48.75)

39 (42.86)

0.531^b

Education, y

11.61 (4.76)

11.00 (4.84)

11.39 (4.92)

12.27 (4.50)

0.212^a

APOE4 positivity, n (%)

44 (18.26)

14 (20.00)

15 (18.75)

15 (16.48)

0.841^b

VRS, %

17.57 (16.47)

16.90 (14.33)

18.54 (17.18)

17.22 (17.47)

0.806^a

MMSE

26.82 (2.67)

26.34 (2.44)

26. 93 (3.29)

27.10 (2.18)

0.189^a

BMI, kg/m²

24.18 (2.92)

24.29 (3.06)

24.00 (2.80)

24.25 (2.94)

0.793^a

GDS score

4.93 (5.09)

5.04 (5.24)

5.63 (5.26)

4.22 (4.76)

0.192^a

Annual income status

0.887^c

  < MCL, n (%)

15 (6.22)

3 (4.29)

5 (6.25)

7 (7.69)

 ≥MCL, < 2 × MCL, n (%)

115 (47.72)

32 (45.71)

40 (50.00)

43 (47.25)

 ≥2 × MCL, n (%)

111 (46.06)

35 (50.00)

35 (43.75)

41 (45.05)

Zinc, μg/dL

86.85 (11.79)

73.36 (4.90)

85.04 (2.85)

98.80 (7.50)

< 0.001^a

Albumin, g/dL

4.49 (0.25)

4.38 (0.23)

4.53 (0.21)

4.53 (0.27)

< 0.001^a

Copper, μg/dL

102.32 (17.78)

100.73 (20.25)

101.91 (15.62)

103.91 (17.60)

0.515^a

Calcium, mg/dL

9.45 (0.31)

9.35 (0.30)

9.46 (0.29)

9.50 (0.32)

0.010^a

Iron, μg/dL

122.61 (40.75)

111.59 (41.13)

116.84 (38.35)

136.18 (39.13)

< 0.001^a

Transferrin, mg/dL

271.15 (39.38)

262.74 (37.04)

271.26 (38.67)

277.51 (40.92)

0.061^a

Ceruloplasmin, mg/dL

24.14 (5.08)

23.91 (5.78)

24.87 (4.41)

23.67 (5.04)

0.276^a

Total cholesterol, mg/dL

183.57 (31.49)

181.50 (27.66)

180.75 (28.86)

187.64 (36.05)

0.293^a

Nutritional deficiency

36 (14.94)

10 (14.29)

13 (16.25)

13 (14.29)

0.922^b

Neuroimage biomarkers

 Cerebral Aβ deposition

  Aβ retention, SUVR

1.20 (0.23)

1.26 (0.34)

1.20 (0.21)

1.16 (0.12)

0.021^a

 Cerebral tau deposition (n = 58)

  AV-1451, SUVR

1.34 (0.26)

1.36 (0.30)

1.29 (0.21)

1.38 (0.24)

0.575^a

 AD-CM, SUVR

1.42 (0.12)

1.39 (0.13)

1.41 (0.12)

1.44 (0.12)

0.077^a

 WMH volume, cm³

12.29 (11.68)

11.14 (10.13)

12.91 (12.37)

12.65 (12.25)

0.625^a