The authors have no potential conflicts of interest to disclose.
Author Contributions
Conceptulization: Ji Won Han, Ki Woong Kim. Data curation: Ji Won Han. Formal Analysis & Software & Visualization: Soomin Jang, Jiyoon Shin, Ji Won Han, Ki Woong Kim. Funding acquisition: Ki Woong Kim. Investigation & Methodology & Resources & Writing—review & editing: Ji Won Han, Tae Hui Kim, Kyung Phil Kwak, Kayoung Kim, Bong Jo Kim, Shin Gyeom Kim, Jeong Lan Kim, Tae Hyun Kim, Seok Woo Moon, Jae Young Park, Joon Hyuk Park, Seonjeong Byun, Seung Wan Suh, Jiyeong Seo, Yoonseop So, Seung-Ho Ryu, Jong Chul Youn, Kyoung Hwan Lee, Dong Young Lee, Dong Woo Lee, Seok Bum Lee, Jung Jae Lee, Ju Ri Lee, Hyeon Jeong, Hyun-Ghang Jeong, Jin Hyeong Jhoo, Kyuhee Han, Jong Woo Hong, Ki Woong Kim. Project administration & Supervision & Validation: Ji Won Han, Ki Woong Kim. Writing—original draft: Soomin Jang, Ji Won Han, Ki Woong Kim.
Total (N=3,910) |
Baseline serum folate levels |
p value* | post-hoc† | ||||
---|---|---|---|---|---|---|---|
1st quartile (N=991) | 2nd quartile (N=991) | 3rd quartile (N=973) | 4th quartile (N=955) | ||||
Folate (ng/mL) (range) | 8.6±3.4 (≥1.5, ≤16.9) | 4.6±1.0 (≥1.5, ≤5.9) | 7.10±0.7 (>5.9, ≤8.2) | 9.6±0.8 (>8.2, ≤11.0) | 13.4±1.7 (>11.0, ≤16.9) | <0.001 | 1<2<3<4 |
Age (years) | 69.5±6.7 | 70.6±7.3 | 69.5±6.4 | 68.8±6.5 | 69.0±6.3 | <0.001 | 1>2,3,4 |
Female (N, %) | 2,151 (55.0) | 391 (39.5) | 540 (54.5) | 584 (60.0) | 636 (66.6) | <0.001 | |
Education (years) | 8.4±5.3 | 8.0±5.2 | 8.0±5.3 | 8.7±5.2 | 8.8±5.4 | <0.001 | 1,2<3,4 |
GDS-K (points) | 9.7±6.6 | 10.1±6.8 | 9.7±6.4 | 9.6±6.6 | 9.5±6.5 | 0.202 | |
Baseline diagnosis (N, %) | |||||||
Normal cognition | 2,746 (70.2) | 639 (64.5) | 700 (70.6) | 708 (72.8) | 699 (73.2) | <0.001 | |
MCI | 1,044 (26.7) | 306 (30.9) | 267 (26.9) | 241 (24.8) | 230 (24.1) | ||
Dementia | 120 (3.1) | 46 (4.6) | 24 (2.4) | 24 (2.5) | 26 (2.7) |
Variables | B | S.E. | Wald | Sig.† | OR (95% CI) |
---|---|---|---|---|---|
1st quartile (≤ 5.9 ng/mL) | 0.273 | 0.109 | 6.299 | 0.012 | 1.314 (1.062–1.626) |
2nd quartile (≤ 8.2 ng/mL) | 0.066 | 0.108 | 0.375 | 0.541 | 1.068 (0.865–1.319) |
3rd quartile (≤11.0 ng/mL) | 0.032 | 0.108 | 0.087 | 0.768 | 1.032 (0.835–1.277) |
4th quartile (>11.0 ng/mL) | Ref. |
B | SE | Wald | Sig.† | OR (95% CI) | |
---|---|---|---|---|---|
MCI | 0.276 | 0.157 | 3.086 | 0.079 | 1.318 (0.969–1.793) |
Dementia | 0.860 | 0.400 | 4.630 | 0.031 | 2.364 (1.080–5.177) |
* the participants whose serum folate level was within the 2nd–4th quartile at baseline but declined to the lowest quartile at the 4-year followup evaluation,
† multinomial logistic regression that computed age, sex, education, presence of apolipoprotein ε4 allele, Geriatric Depression Scale, presence of hypertension, diabetes mellitus, body mass index, total cholesterol, serum creatinine, alcohol intake, smoking, and serum vitamin B12 level as covariates.