Researchers: Paulina Maria Przybycien-Gaweda, Tih Shih Lee, Wee Shiong Lim, Mei Sian Chong, Philip Yap, Chin Yee Cheong, Iris Rawtaer, Tau Ming Liew, Xinyi Gwee, Qi Gao, Keng Bee Yap, Tze Pin Ng
There is a lack of evidence supporting an association between folate and vitamin B12 exposure with cognitive outcomes. We examined serum folate and vitamin B12 and plasma homocysteine in 690 cognitively-normal adults (aged ≥ 55) from the Singapore Longitudinal Aging Study (SLAS-2) followed-up over 4.5 years on incident neurocognitive disorder (NCD): mild cognitive impairment (MCI) and dementia. At follow-up, 5.7% (39) of participants developed NCD (34 MCI and 5 dementia). Comparing with those who remained cognitively-normal, participants progressed to NCD had significantly lower mean baseline vitamin B12 (420 [SD ± 221] vs. 510 [SD ± 290] pmol/L, p = 0.026), higher homocysteine (14.6 [SD ± 4.2] vs. 12.9 [SD ± 4.3], p = 0.018) and lower one-carbon index (Z-scores: -0.444 [SD ± 0.819] vs. -0.001 [SD ± 0.990], p = 0.006). Adjusted for confounders, significant associations with incident NCD were found for lower vitamin B12 (per-SD OR = 2.10, 95%CI = 1.26-3.52), higher homocysteine (per-SD OR = 1.96, 95%CI = 1.18-3.24) and lower one-carbon index (per-SD OR = 1.67, 95%CI = 1.06-2.64). Folate was not significantly associated with progression to NCD. Notably, low B12 in the presence of high folate was significantly associated with incident NCD (adjusted OR = 3.81, 95%CI = 1.04-13.9). Low B12, high homocysteine, low B12 in the presence of high folate, and a one-carbon index of hypo-methylation were independently associated with progression to NCD among cognitively normal.
References
Topic: Vitamin B12 for Elderly