Table 1 Demographics and clinical characteristics

Age, years

70.4 (7.9)

66.0 (7.4)

73.3 (6.9)^a

Male sex, n (%)

43 (35.83%)

17 (35.42%)

26 (36.11%)

Education, years

12.4 (2.6)

13.2 (2.3)

11.8 (2.7)^a

MMSE score, mean

26.9 (3.1)

28.5 (1.4)

25.9 (3.5)^a

APOE ε4 carrier, n (%)

37 (30.83%)

11 (22.92%)

26 (36.11%)^a

 Aβ_1–42, pg/ml

847.4 (265.1)

957.4 (194.0)

774.0 (281.5)^a

 tau, pg/ml

371.3 (278.6)

221.5 (82.9)

471.1 (316.6)^a

 p-tau181, pg/ml

62.0 (35.2)

45.9 (13.3)

72.7 (40.9)^a

 p-tau181/Aβ_1–42

0.088 (0.082)

0.049 (0.015)

0.114 (0.097)^a

 Albumin index^b

6.1 (2.4)

5.3 (1.9)

6.6 (2.5)^a

 Choline, μM

2.7 (0.5)

2.6 (0.4)

2.8 (0.6)^a

 Cystathionine, nM

35.8 (17.0)

34.4 (13.8)

36.7 (18.9)

 Methionine, μM

3.6 (0.8)

3.3 (0.5)

3.9 (0.9)^a

  S-adenosylhomocysteine, nM

15.1 (5.8)

13.5 (4.3)

16.1 (6.3)^a

  S-adenosylmethionine, nM

183.0 (42.0)

188.2 (41.1)

179.4 (42.5)

 Serine, μM

27.1 (4.7)

25.7 (4.1)

28.0 (4.8)^a

 Cysteine, μM

1.2 (0.4)

1.2 (0.4)

1.3 (0.4)

 5-Methyltetrahydrofolate, nM

45.1 (12.5)

47.2 (10.9)

43.8 (13.4)

 Cystathionine, nM

252.3 (232.4)

267.5 (290.0)

242.1 (185.9)

 Glycine, μM

234.5 (60.6)

235.9 (59.7)

233.6 (61.5)

 Methionine, μM

19.7 (3.6)

19.4 (2.9)

19.9 (4.1)

  S-adenosylhomocysteine, nM

20.9 (9.1)

18.3 (6.3)

22.7 (10.2)^a

  S-adenosylmethionine, nM

71.9 (20.7)

67.6 (17.7)

74.7 (22.2)

 Serine, μM

115.3 (19.9)

111.5 (16.9)

117.9 (21.3)

 Cysteine, μM

158.3 (20.3)

150.7 (18.4)

163.3 (20.1)^a

 Homocysteine, μM

5.6 (1.6)

5.3 (1.5)

5.8 (1.7)