Normal-But-Low Serum Folate Levels and the Risks for Cognitive Impairment

• DOI: 10.30773/pi.2019.05.29
• Publication Date: 2019-07-26T00:42:58Z
• Authors: Soomin Jang; Ji Won Han; Jiyoon Shin; 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
• Keywords: 03 medical and health sciences; 0302 clinical medicine; Original Article; 3. Good health

This study aimed to examine the association between normal-but-low folate levels and cognitive function in the elderly population using a prospective cohort study.We analyzed 3,910 participants whose serum folate levels were within the normal reference range (1.5-16.9 ng/mL) at baseline evaluation in the population-based prospective cohort study named the "Korean Longitudinal Study on Cognitive Aging and Dementia." The association between baseline folate quartile categories and baseline cognitive disorders [mild cognitive impairment (MCI) or dementia] was examined using binary logistic regression analysis adjusting for confounding variables. The risks of incident MCI and dementia associated with the decline of serum folate level during a 4-year follow-up period were examined using multinomial logistic regression analysis.The lowest quartile group of serum folate (≥1.5, ≤5.9 ng/mL) showed a higher risk of cognitive disorders than did the highest quartile group at baseline evaluation (odds ratio 1.314, p=0.012). Over the 4 years of follow-up, the risk of incident dementia was 2.364 times higher among subjects whose serum folate levels declined from the 2nd-4th quartile group to the 1st quartile than among those for whom it did not (p=0.031).Normal-but-low serum folate levels were associated with the risk of cognitive disorders in the elderly population, and a decline to normal-but-low serum folate levels was associated with incident dementia. Maintaining serum folate concentration above 5.9 ng/mL may be beneficial for cognitive status.