Plasma Methylmalonic Acid in Relation to Serum Cobalamin and Plasma Homocysteine in a Psychogeriatric Population and the Effect of Cobalamin Treatment

Nilsson, Karin; Gustafson, Lars; Fäldt, R.; Anderson, Anders H.; Vaara, Ivar; Nilsson, Roland; Alm, B.; Hultberg, Björn

doi:10.1002/(sici)1099-1166(199701)12:1<67::aid-gps464>3.0.co;2-f

Cited by 25 publications

(5 citation statements)

References 20 publications

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“…The upper reference limit (95th percentile) for plasma homocysteine in an elderly population is 19.9 µm o l / l (22). In the present and earlier studies (20,22,23), however, we have used 150 pmol/l as the lower reference limits for serum cobalamins, since this value is used in most studies in this field. The reference interval for serum cobalamin is 110-650 pmol/l and for blood folate 125-500 nmol/l.…”

Section: Assaysmentioning

confidence: 92%

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Concentrations of Plasma Methylmalonic Acid in 80-Year-Olds Show Only Weak Relation to Psychological Performance

Hultberg¹,

Jensen²,

Dehlin³

et al. 1999

CCLM

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Most studies of the relation between psychological performance in the elderly and deficiencies of cobalamin and folate have used methods that determine the blood concentrations of these vitamins, which might not reflect the vitamin status in the tissues. Recently, two new markers, plasma homocysteine and methylmalonic acid, have attracted growing interest since they are considered to reflect the status of cobalamins and folates in the tissues. In a previous study, we noted a strong association between five parameters of well-being and lower concentrations of plasma homocysteine. In the present study, we have extended these observations by determination of plasma methylmalonic acid in the same healthy elderly population. In the present study, 18 out of 100 subjects had increased plasma methylmalonic acid and in 7 of these subjects, the concentrations of serum cobalamin, blood folate, plasma homocysteine and serum creatinine were within normal limits. The relation between plasma methylmalonic acid concentrations and concentrations of serum cobalamin and blood folates and five parameters of well-being were investigated. Concentrations of plasma methylmalonic acid were only weakly associated with the concentrations of serum cobalamin and lower scores on the logical reasoning test. The present study clearly shows that the levels of plasma methylmalonic acid show a much lesser association with the parameters of well-being than did plasma homocysteine.

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Section: Assaysmentioning

confidence: 92%

“…The upper reference limit (95th percentile) for plasma methylmalonic acid in an elderly population is 0.41 µmol/l (20). The plasma was stored at -20° C until analysis.…”

Section: Assaysmentioning

confidence: 99%

Concentrations of Plasma Methylmalonic Acid in 80-Year-Olds Show Only Weak Relation to Psychological Performance

Hultberg¹,

Jensen²,

Dehlin³

et al. 1999

CCLM

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“…The plasma was stored at y208C until analysis. The upper reference limit (95th percentile) for tHcy in a healthy elderly population (with normal serum cobalamin, blood folate and serum creatinine) is 19.9 mmol/l (19) and that for plasma MMA 0.41 mmol/l (20). The method has a coefficient of variation of 4%, calculated at the level of 15 mmol/l.…”

Section: Assaysmentioning

confidence: 99%

“…For cobalamin in serum we used the reference interval of 150-650 pmol/l (16,19,20), which is commonly used in Scandinavian countries. For serum cobalamin we used the AutoDELFIA B12 kit (Wallac Oy, Turku, Finland).…”

Section: Assaysmentioning

confidence: 99%

Clinical utility of serum holotranscobalamin as a marker of cobalamin status in elderly patients with neuropsychiatric symptoms

Nilsson¹,

Isaksson²,

Gustafson³

et al. 2004

Clinical Chemistry and Laboratory Medicine (CCLM)

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Early diagnosis of cobalamin deficiency is crucial, owing to the latent nature of this disorder and the resulting possible irreversible neurological damage. A normal serum cobalamin concentration does not reliably rule out a functional cobalamin deficiency and there does not at present seem to be any single diagnostic approach to achieve this diagnosis. A new marker for cobalamin status is the serum concentration of cobalamin bound to transcobalamin II (holoTC). Because methods suitable for routine use have been unavailable until recently, the clinical value of low holoTC is still uncertain. Furthermore, there is at the moment no gold standard or true reference method to diagnose subtle cobalamin deficiency, which makes evaluation of the clinical usefulness of holoTC and the estimation of sensitivity and specificity problematic. In this study, we aimed to assess whether low holoTC concentrations are congruent with other biochemical signs of cobalamin deficiency in a group of psychogeriatric patients. The findings in the present study show that holoTC is strongly related to serum cobalamin (0.68; p<0.001 in both patients and controls). Distribution of the different markers for cobalamin/folate status in the 33 patients with low levels of serum holoTC (below 40 pmol/l) showed that 17 patients had normal levels of the other markers for cobalamin status. This may indicate poor specificity of low holoTC for cobalamin deficiency. In 23 out of 176 patients with normal levels of holoTC we observed pathological levels of other markers for cobalamin deficiency. The use of holoTC in the present study group did not give significant additional information other than that given by serum cobalamin and therefore cannot be recommended in this clinical setting.

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“…Several studies suggest that P‐MMA is a more specific and sensitive marker than plasma cobalamins. For that reason P‐MMA has been introduced as a primary or additional diagnostic test [2–8], and some have suggested that cobalamin deficiency should be defined as an increased P‐MMA that decreases upon appropriate treatment [2, 9–11]. Based upon P‐MMA measurements, the prevalence of cobalamin deficiency has been estimated to be about 15% in the elderly population [12, 13].…”

Section: Introductionmentioning

confidence: 99%

Physicians’ use of plasma methylmalonic acid as a diagnostic tool

Hvas

Vestergaard

Gerdes

et al. 2000

Journal of Internal Medicine

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Plasma Methylmalonic Acid in Relation to Serum Cobalamin and Plasma Homocysteine in a Psychogeriatric Population and the Effect of Cobalamin Treatment

Cited by 25 publications

References 20 publications

Concentrations of Plasma Methylmalonic Acid in 80-Year-Olds Show Only Weak Relation to Psychological Performance

Concentrations of Plasma Methylmalonic Acid in 80-Year-Olds Show Only Weak Relation to Psychological Performance

Clinical utility of serum holotranscobalamin as a marker of cobalamin status in elderly patients with neuropsychiatric symptoms

Physicians’ use of plasma methylmalonic acid as a diagnostic tool

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