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A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12.

Abstract

BACKGROUND & AIMS

Older diabetic people are at risk of cognitive decline. Vitamin B12 deficiency in older people is associated with cognitive impairment and Alzheimer's disease. Vitamin B12 deficiency may therefore contribute to cognitive decline in older diabetic people. We therefore performed a randomized placebo-controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with mild vitamin B12 deficiency.

METHODS

271 diabetic non-demented outpatients aged 70 years or older with plasma vitamin B12 150-300 pmol/L in outpatient clinics were randomly assigned to take either methylcobalamin 1000 μg or two similar looking placebo tablets once daily for 27 months. All subjects were followed up at 9 monthly intervals. The primary outcome is cognitive decline as defined by an increase in clinical dementia rating scale (CDR) global score. The secondary outcomes included Neuropsychological Test Battery (NTB) z-scores, serum methymalonic acid (MMA) and homocysteine.

RESULTS

The subjects in the trial groups were well matched in clinical characteristics, except that active intervention group had more smokers. 46.5% and 74.1% had elevated serum methymalonic acid (≥0.21 μmol/L) and homocysteine (≥13 μmol/L) respectively. 44% of the subjects had CDR score of 0.5 suggesting questionable dementia. At month 9 and 27, serum MMA and homocysteine was significantly reduced in the active treatment group, when compared with placebo group. (P < 0.0001, student t test) At month 27, there was no significant group difference in changes in CDR or NTB z-scores. Exclusion of smokers did not alter the results. Subgroup analysis of high MMSE and serum MMA showed similar results.

CONCLUSION

Vitamin B12 supplementation did not prevent cognitive decline in older diabetic patients with borderline vitamin B12 status.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02457507.

Links

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  • Authors+Show Affiliations

    ,

    Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. Electronic address: tkwok@cuhk.edu.hk.

    ,

    Department of Medicine, Alice Ho Mui Ming Nethersole Hospital, Taipo, Hong Kong. Electronic address: jennylee@cuhk.edu.hk.

    ,

    Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. Electronic address: rcwma@cuhk.edu.hk.

    ,

    Department of Family Medicine, Prince of Wales Hospital, Shatin, Hong Kong. Electronic address: yeungshanwong@cuhk.edu.hk.

    ,

    Department of Family Medicine and Primary Care, University of Hong Kong, Hong Kong. Electronic address: kkung@hku.hk.

    ,

    Department of Family Medicine, Prince of Wales Hospital, Shatin, Hong Kong. Electronic address: lamt@ha.org.hk.

    ,

    Department of Chemical Pathology, Prince of Wales Hospital, Shatin, Hong Kong. Electronic address: chungshunho@cuhk.edu.hk.

    ,

    Department of Pharmacy, The Chinese University of Hong Kong, Hong Kong. Electronic address: vivianlee@pharmacy.cuhk.edu.hk.

    ,

    Alzheimer Center, VU Medical Center, Amsterdam, The Netherlands. Electronic address: john@metiscog.com.

    Department of Psychiatry, The Chinese University of Hong Kong, Taipo Hospital, Taipo, Hong Kong. Electronic address: cwlam@cuhk.edu.hk.

    Source

    MeSH

    Aged
    Cholesterol
    Cognitive Dysfunction
    Creatinine
    Diabetes Mellitus
    Dietary Supplements
    Female
    Follow-Up Studies
    Homocysteine
    Humans
    Male
    Methylmalonic Acid
    Neuropsychological Tests
    Socioeconomic Factors
    Triglycerides
    Vitamin B 12

    Pub Type(s)

    Journal Article
    Randomized Controlled Trial

    Language

    eng

    PubMed ID

    27823800

    Citation

    Kwok, Timothy, et al. "A Randomized Placebo Controlled Trial of Vitamin B12 Supplementation to Prevent Cognitive Decline in Older Diabetic People With Borderline Low Serum Vitamin B12." Clinical Nutrition (Edinburgh, Scotland), vol. 36, no. 6, 2017, pp. 1509-1515.
    Kwok T, Lee J, Ma RC, et al. A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12. Clin Nutr. 2017;36(6):1509-1515.
    Kwok, T., Lee, J., Ma, R. C., Wong, S. Y., Kung, K., Lam, A., ... Lam, L. (2017). A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12. Clinical Nutrition (Edinburgh, Scotland), 36(6), pp. 1509-1515. doi:10.1016/j.clnu.2016.10.018.
    Kwok T, et al. A Randomized Placebo Controlled Trial of Vitamin B12 Supplementation to Prevent Cognitive Decline in Older Diabetic People With Borderline Low Serum Vitamin B12. Clin Nutr. 2017;36(6):1509-1515. PubMed PMID: 27823800.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12. AU - Kwok,Timothy, AU - Lee,Jenny, AU - Ma,Ronald C, AU - Wong,Samuel Y, AU - Kung,Kenny, AU - Lam,Augustine, AU - Ho,C S, AU - Lee,Vivian, AU - Harrison,John, AU - Lam,Linda, Y1 - 2016/10/27/ PY - 2015/05/29/received PY - 2016/04/19/revised PY - 2016/10/19/accepted PY - 2016/11/9/pubmed PY - 2018/7/18/medline PY - 2016/11/9/entrez KW - Cognitive disorder KW - Diabetes mellitus KW - Elderly KW - Randomized trial KW - Vitamin B(12) SP - 1509 EP - 1515 JF - Clinical nutrition (Edinburgh, Scotland) JO - Clin Nutr VL - 36 IS - 6 N2 - BACKGROUND & AIMS: Older diabetic people are at risk of cognitive decline. Vitamin B12 deficiency in older people is associated with cognitive impairment and Alzheimer's disease. Vitamin B12 deficiency may therefore contribute to cognitive decline in older diabetic people. We therefore performed a randomized placebo-controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with mild vitamin B12 deficiency. METHODS: 271 diabetic non-demented outpatients aged 70 years or older with plasma vitamin B12 150-300 pmol/L in outpatient clinics were randomly assigned to take either methylcobalamin 1000 μg or two similar looking placebo tablets once daily for 27 months. All subjects were followed up at 9 monthly intervals. The primary outcome is cognitive decline as defined by an increase in clinical dementia rating scale (CDR) global score. The secondary outcomes included Neuropsychological Test Battery (NTB) z-scores, serum methymalonic acid (MMA) and homocysteine. RESULTS: The subjects in the trial groups were well matched in clinical characteristics, except that active intervention group had more smokers. 46.5% and 74.1% had elevated serum methymalonic acid (≥0.21 μmol/L) and homocysteine (≥13 μmol/L) respectively. 44% of the subjects had CDR score of 0.5 suggesting questionable dementia. At month 9 and 27, serum MMA and homocysteine was significantly reduced in the active treatment group, when compared with placebo group. (P < 0.0001, student t test) At month 27, there was no significant group difference in changes in CDR or NTB z-scores. Exclusion of smokers did not alter the results. Subgroup analysis of high MMSE and serum MMA showed similar results. CONCLUSION: Vitamin B12 supplementation did not prevent cognitive decline in older diabetic patients with borderline vitamin B12 status. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT02457507. SN - 1532-1983 UR - https://www.unboundmedicine.com/medline/citation/27823800/A_randomized_placebo_controlled_trial_of_vitamin_B12_supplementation_to_prevent_cognitive_decline_in_older_diabetic_people_with_borderline_low_serum_vitamin_B12_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0261-5614(16)31308-5 DB - PRIME DP - Unbound Medicine ER -