Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda MD, USA.
Am J Clin Nutr. 2011 Jan;93(1):47-56. doi: 10.3945/ajcn.110.004341. Epub 2010 Nov 3.
Isolated methylmalonic acidemia (MMA) is managed by dietary protein restriction and medical food supplementation. Resting energy expenditure (REE) can be depressed in affected individuals for undefined reasons.
The objective was to document the spectrum of nutritional approaches used to treat patients with MMA, measure REE, and analyze the dependence of REE on body composition, biochemical, and nutritional variables.
Twenty-nine patients with isolated MMA (22 mut, 5 cblA, 2 cblB; 15 males, 14 females; age range: 2-35 y) underwent evaluation. REE was measured with open-circuit calorimetry and compared with predicted values by using age-appropriate equations.
Nutritional regimens were as follows: protein restriction with medical food (n = 17 of 29), protein restriction with medical food and supplemental isoleucine or valine (n = 5 of 29), or the use of natural protein alone for dietary needs (n = 7 of 29). Most mut patients had short stature and higher percentage fat mass compared with reference controls. Measured REE decreased to 74 ± 13.6% of predicted (P < 0.001) in the ≤ 18-y group (n = 22) and to 83 ± 11.1% (P = 0.004) in patients aged >18 y (n = 7). Linear regression modeling suggested that age (P = 0.001), creatinine clearance (P = 0.01), and height z score (P = 0.04) accounted for part of the variance of measured REE per kilogram of fat-free mass (model R² = 0.66, P < 0.0001).
There is wide variation in the dietary treatment of MMA. Standard predictive equations overestimate REE in this population primarily due to their altered body composition and decreased renal function. Defining actual energy needs will help optimize nutrition and protect individuals from overfeeding. This trial is registered at clinicaltrials.gov as NCT00078078.
孤立性甲基丙二酸血症（MMA）通过限制蛋白质摄入和使用医学食品来治疗。由于未知原因，受影响个体的静息能量消耗（REE）可能会降低。
本研究旨在记录用于治疗 MMA 患者的各种营养方法，测量 REE，并分析 REE 与身体成分、生化和营养变量的关系。
对 29 例孤立性 MMA 患者（22 例 mut，5 例 cblA，2 例 cblB；15 名男性，14 名女性；年龄范围：2-35 岁）进行评估。使用开路量热法测量 REE，并使用适合年龄的方程与预测值进行比较。
营养方案如下：29 例患者中有 17 例（17/29）采用限制蛋白质摄入和医学食品治疗，5 例（5/29）采用限制蛋白质摄入和补充异亮氨酸或缬氨酸，7 例（7/29）采用天然蛋白质满足饮食需求。大多数 mut 患者的身高较矮，体脂百分比较高。≤18 岁组（n=22）实测 REE 下降至预测值的 74±13.6%（P＜0.001），＞18 岁组（n=7）患者下降至 83±11.1%（P=0.004）。线性回归模型表明，年龄（P=0.001）、肌酐清除率（P=0.01）和身高 z 评分（P=0.04）部分解释了实测 REE 与去脂体重的关系（模型 R²=0.66，P＜0.0001）。
MMA 的饮食治疗存在很大差异。由于身体成分改变和肾功能下降，这些人群使用标准预测方程会高估 REE。确定实际能量需求将有助于优化营养，并防止个体过度喂养。本试验在 clinicaltrials.gov 注册，编号为 NCT00078078。
