Hogeveen Marije, van Beynum Ingrid, van Rooij Arno, Kluijtmans Leo, den Heijer Martin, Blom Henk
Dept. of Paediatrics, Metabolic and Endocrine Diseases, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
Eur J Nutr. 2008 Feb;47(1):26-31. doi: 10.1007/s00394-007-0692-5. Epub 2007 Dec 18.
Plasma methylmalonic acid (MMA) is a specific marker for functional cobalamin deficiency. This deficiency can give rise to non-specific but serious symptoms in childhood such as developmental delay, convulsions and failure to thrive and may even lead to irreversible neurological damage.
To analyse plasma MMA concentrations in Dutch children and to evaluate possible factors influencing its concentration.
A number of 186 Dutch children aged 0-19 years were analysed cross-sectionally. Blood was collected to measure MMA, total homocysteine (tHcy), cobalamin (Cbl) and serum creatinine concentrations. In addition, information about medical history, age and sex was recorded.
The geometric mean (GM) plasma MMA concentration was 0.17 micromol/l (95% CI 0.07-0.42) and the GM tHcy was 6.6 micromol/l (95% CI 3.1-13.9). There is a slight positive correlation between plasma MMA and age in children >1 year (r = 0.211, P < 0.05). Plasma MMA concentrations were significantly higher in children with low Cbl concentrations. No significant difference in MMA, Cbl, tHcy or creatinine concentrations between sexes could be observed. Regression analysis showed that Cbl was the strongest determinant of plasma MMA (regression coefficient -0.414, P < 0.05). The association between MMA and Cbl is stronger at increasing age (P for trend 0.045).
Plasma Cbl is the main determinant of MMA in this group of Dutch children. The strength of the association increased with increasing age.
血浆甲基丙二酸（MMA）是功能性钴胺素缺乏的特异性标志物。这种缺乏在儿童期可引发非特异性但严重的症状，如发育迟缓、惊厥和生长发育不良，甚至可能导致不可逆的神经损伤。
分析荷兰儿童的血浆MMA浓度，并评估影响其浓度的可能因素。
对186名年龄在0至19岁的荷兰儿童进行横断面分析。采集血液以测量MMA、总同型半胱氨酸（tHcy）、钴胺素（Cbl）和血清肌酐浓度。此外，记录有关病史、年龄和性别的信息。
血浆MMA浓度的几何平均值（GM）为0.17微摩尔/升（95%可信区间0.07 - 0.42），GM tHcy为6.6微摩尔/升（95%可信区间3.1 - 13.9）。1岁以上儿童的血浆MMA与年龄之间存在轻微正相关（r = 0.211，P < 0.05）。Cbl浓度低的儿童血浆MMA浓度显著更高。未观察到性别之间MMA、Cbl、tHcy或肌酐浓度的显著差异。回归分析表明，Cbl是血浆MMA的最强决定因素（回归系数 -0.414，P < 0.05）。随着年龄增长，MMA与Cbl之间的关联更强（趋势P值为0.045）。
在这群荷兰儿童中，血浆Cbl是MMA的主要决定因素。随着年龄增长，这种关联的强度增加。
