Homocysteine and nutritional biomarkers in cognitive impairment

Cognitive impairment is a progressive disorder that affects the ageing population. With the increase in the mean age of our population, it is becoming a public health problem. Homocysteinemia has been implicated in cognitive impairment. Whilst it is modulated by vitamins B12 and folate, it acts through MMPs 2 and 9. To assesses the relationship of cognitive impairment with homocysteine, B12, folate and MMPs 2 and 9, so as to detect cases of mild cognitive impairment which are potentially reversible, blood samples were drawn from 73 enrolled subjects, with and without cognitive impairment on basis of Montreal cognitive assessment (MoCA) score < 25 or ≥ 25, respectively. Homocysteine, B12, folate and MMPs2 and 9 were estimated. Correlation between MoCA score and these parameters was elucidated. After adjusting for age and gender, homocysteine was the only significant independent predictor of MoCA score. Cut-off of homocysteine for prediction of MoCA < 25 was derived at 13.5 µmol/L(PPV = 59.6%; NPV = 79.2%). The equation derived for calculation of MoCA score from homocysteine is: MoCA score = 32.893 + [(- 0.223)(homocysteine in μmol/L)]. Homocysteine > 13.5 μmol/L predicts low MoCA (< 25) with 84.8% sensitivity and 50% specificity. Hence, patients with an Hcy > 13.5 μmol/L should be administered B12 and folate to reduce homocysteine, a modifiable risk factor of cognitive decline. Also, a novel equation for calculating MoCA score from homocysteine has been derived. Using this derived equation to calculate MoCA score, it may be possible to identify asymptomatic subjects with early cognitive impairment.