OBJECTIVE: To determine whether low serum B12 levels are associated with an increased incidence of dementing illness. DESIGN: Longitudinal cohort study, 5-year follow-up. PARTICIPANTS: Volunteer cohort of 410 nondemented ambulatory subjects aged 75 to 85 years. MEASUREMENTS: Annual serum B12 determinations and neuropsychological assessments including the Blessed Test of Information, Memory and Concentration (BIMC) and the Fuld Object Memory Evaluation (FOME). If subject met criteria for a major cognitive change (as defined by an increase of 4 or more points on the BIMC), a work-up that included CT, EEG, and neurologic assessment was performed. Clinical diagnoses were made according to established criteria. RESULTS: Mean serum B12 level of entire sample was 558 pg/mL. Twenty-two subjects had low B12 levels defined as values < 150 pg/mL. Three of these 22 subjects (13.6%) became demented, compared with 57 of 388 subjects (14.7%) with higher levels. The incidence of Alzheimer disease among the low B12 group was 4.5% compared with 7.5% in the higher B12 group. The mean B12 level at time of diagnosis in subjects who did develop Alzheimer disease was 551 pg/mL. There was no evidence of hematologic disorder among the 22 subjects with low B12. Of the 3 low B12 subjects who did become demented, none responded to monthly B12 injections. CONCLUSION: A low B12 level may not be a risk factor for dementia in general or Alzheimer disease in particular.
OBJECTIVE: To determine whether low serum B12 levels are associated with an increased incidence of dementing illness. DESIGN: Longitudinal cohort study, 5-year follow-up. PARTICIPANTS: Volunteer cohort of 410 nondemented ambulatory subjects aged 75 to 85 years. MEASUREMENTS: Annual serum B12 determinations and neuropsychological assessments including the Blessed Test of Information, Memory and Concentration (BIMC) and the Fuld Object Memory Evaluation (FOME). If subject met criteria for a major cognitive change (as defined by an increase of 4 or more points on the BIMC), a work-up that included CT, EEG, and neurologic assessment was performed. Clinical diagnoses were made according to established criteria. RESULTS: Mean serum B12 level of entire sample was 558 pg/mL. Twenty-two subjects had low B12 levels defined as values < 150 pg/mL. Three of these 22 subjects (13.6%) became demented, compared with 57 of 388 subjects (14.7%) with higher levels. The incidence of Alzheimer disease among the low B12 group was 4.5% compared with 7.5% in the higher B12 group. The mean B12 level at time of diagnosis in subjects who did develop Alzheimer disease was 551 pg/mL. There was no evidence of hematologic disorder among the 22 subjects with low B12. Of the 3 low B12 subjects who did become demented, none responded to monthly B12 injections. CONCLUSION: A low B12 level may not be a risk factor for dementia in general or Alzheimer disease in particular.
Authors: Martha Clare Morris; Denis A Evans; Julie A Schneider; Christine C Tangney; Julia L Bienias; Neelum T Aggarwal Journal: J Alzheimers Dis Date: 2006-08 Impact factor: 4.472
Authors: S Hengstermann; G Laemmler; A Hanemann; A Schweter; E Steinhagen-Thiessen; A Lun; R-J Schulz Journal: J Nutr Health Aging Date: 2009-02 Impact factor: 4.075
Authors: S Hengstermann; G Laemmler; A Hanemann; A Schweter; E Steinhagen-Thiessen; A Lun; R-J Schulz Journal: J Nutr Health Aging Date: 2008 Jun-Jul Impact factor: 4.075