A M Hvas1, J Ellegaard, E Nexø. 1. Department of Hematology, Aarhus University Hospital, Aarhus Amtssygehus, Tage Hansens Gade 2, 8000 Aarhus C, Denmark. Anne_Mette.Hvas@aas.auh.dk
Abstract
BACKGROUND: The prevalence of vitamin B(12) deficiency, defined as an elevated concentration of plasma methylmalonic acid (P-MMA), has been estimated to be 15% to 44% in the elderly. However, we do not know whether an increased P-MMA level actually indicates or predicts a clinical condition in need of treatment. PARTICIPANTS AND METHODS: In a follow-up study, 432 individuals not treated with vitamin B(12) were examined 1.0 to 3.9 years after initial observation of an increased P-MMA concentration (>0.28 micromol/L). The examination included laboratory tests, a structured interview to disclose symptoms, a food frequency questionnaire, and a clinical examination including a Neurological Disability Score. RESULTS: Variation in P-MMA levels over time was high (coefficient of variation, 34%). In only 16% of participants, P-MMA levels increased substantially, whereas 44% showed a decrease. Level of P-MMA was significantly but not strongly associated with levels of plasma cobalamins (r = -0.22, P<.001) and plasma total homocysteine (r = 0.37, P<.001). After adjustment for age and sex, we found no associations between P-MMA concentration and the total symptom score (P =.61), the total Neurological Disability Score (P =.64), or other clinical manifestations related to vitamin B(12) deficiency. CONCLUSIONS: An increased level of P-MMA did not predict a further increase with time and clinical manifestations related to vitamin B(12) deficiency. We therefore challenge the use of an increased P-MMA concentration as the only marker for diagnosis of vitamin B(12) deficiency.
BACKGROUND: The prevalence of vitamin B(12) deficiency, defined as an elevated concentration of plasma methylmalonic acid (P-MMA), has been estimated to be 15% to 44% in the elderly. However, we do not know whether an increased P-MMA level actually indicates or predicts a clinical condition in need of treatment. PARTICIPANTS AND METHODS: In a follow-up study, 432 individuals not treated with vitamin B(12) were examined 1.0 to 3.9 years after initial observation of an increased P-MMA concentration (>0.28 micromol/L). The examination included laboratory tests, a structured interview to disclose symptoms, a food frequency questionnaire, and a clinical examination including a Neurological Disability Score. RESULTS: Variation in P-MMA levels over time was high (coefficient of variation, 34%). In only 16% of participants, P-MMA levels increased substantially, whereas 44% showed a decrease. Level of P-MMA was significantly but not strongly associated with levels of plasma cobalamins (r = -0.22, P<.001) and plasma total homocysteine (r = 0.37, P<.001). After adjustment for age and sex, we found no associations between P-MMA concentration and the total symptom score (P =.61), the total Neurological Disability Score (P =.64), or other clinical manifestations related to vitamin B(12) deficiency. CONCLUSIONS: An increased level of P-MMA did not predict a further increase with time and clinical manifestations related to vitamin B(12) deficiency. We therefore challenge the use of an increased P-MMA concentration as the only marker for diagnosis of vitamin B(12) deficiency.
Authors: David A Wagner; Richard Schatz; Richard Coston; Cheryl Curington; Daniel Bolt; Phillip P Toskes Journal: J Breath Res Date: 2011-06-23 Impact factor: 3.262
Authors: Elizabeth A Yetley; Christine M Pfeiffer; Karen W Phinney; Regan L Bailey; Sheena Blackmore; Jay L Bock; Lawrence C Brody; Ralph Carmel; L Randy Curtin; Ramón A Durazo-Arvizu; John H Eckfeldt; Ralph Green; Jesse F Gregory; Andrew N Hoofnagle; Donald W Jacobsen; Paul F Jacques; David A Lacher; Anne M Molloy; Joseph Massaro; James L Mills; Ebba Nexo; Jeanne I Rader; Jacob Selhub; Christopher Sempos; Barry Shane; Sally Stabler; Patrick Stover; Tsunenobu Tamura; Alison Tedstone; Susan J Thorpe; Paul M Coates; Clifford L Johnson; Mary Frances Picciano Journal: Am J Clin Nutr Date: 2011-05-18 Impact factor: 7.045