Adductor Pollicis Muscle Thickness as a Marker of Nutritional Status in Heart Failure

Abstract Background: Malnutrition is associated with morbidity and mortality in patients with heart failure (HF). Thus, it is essential to apply reliable indicators to assess the nutritional status of these individuals. Objective: To evaluate the thickness of the adductor pollicis muscle (APM) in patients with HF as an indicator of somatic protein status and correlate the obtained values with conventionally used parameters and electrical bioimpedance (EBI) markers. Methods: Cross-sectional study with patients with HF undergoing regular outpatient treatment. APM thickness was measured in the dominant arm, and the values obtained were classified according to gender and age. The anthropometric parameters assessed included the body mass index (BMI) and specific parameters to assess the muscle (arm muscle circumference [AMC] and arm muscle area [AMA]). Values of phase angle (PA), standard PA (SPA), and lean mass were obtained by EBI. Statistical analyses were performed with the software Statistical Package for the Social Sciences, version 19, using unpaired Student’s t, Mann-Whitney, or one-way analysis of variance (ANOVA) tests for comparisons between groups, as appropriate. The correlation between variables of interest was performed using Pearson’s or Spearman’s correlation coefficient, as adequate. The level of significance was set at 5%. Results: About 70% of the 74 patients evaluated were classified as malnourished according to the APM thickness. Values of AMC, AMA, and lean mass correlated positively with APM thickness (p < 0.005). The APM thickness also correlated positively with PA and SPA (r = 0.49, p < 0.001 and r = 0.31, p = 0.008, respectively). Conclusion: Patients with HF presented a high frequency of protein malnutrition when APM thickness was used as an indicator of nutritional status. APM thickness values correlated with conventional measures of somatic protein evaluation and may be related to the prognosis of these patients, since they correlated positively with PA and SPA.

摘要 背景：营养不良与心力衰竭（HF）患者的发病率和死亡率密切相关，因此采用可靠指标评估此类人群的营养状态至关重要。
目的：评估心力衰竭患者的拇收肌（adductor pollicis muscle, APM）厚度作为躯体蛋白质营养状况的评估指标，并将所得数值与临床常用参数及生物电阻抗分析法（electrical bioimpedance, EBI）标志物进行相关性分析。
方法：本研究为横断面研究，纳入接受规律门诊治疗的心力衰竭患者。对利手侧手臂的拇收肌厚度进行测量，并依据性别与年龄对所得数值进行分组分类。本次评估的人体测量学参数包括体重指数（body mass index, BMI），以及用于评估肌肉状态的特异性指标：上臂肌围（arm muscle circumference, AMC）与上臂肌面积（arm muscle area, AMA）。通过生物电阻抗分析法（EBI）获取相位角（phase angle, PA）、标准相位角（standard PA, SPA）及去脂体重的数值。采用社会科学统计软件包19.0版进行统计学分析，根据组间比较的适宜性选择独立样本t检验、曼-惠特尼U检验或单因素方差分析（one-way analysis of variance, ANOVA）。针对目标变量间的相关性分析，则根据数据特征选用皮尔逊相关系数或斯皮尔曼相关系数。本研究设定显著性水平为5%（即0.05）。
结果：在纳入评估的74例患者中，约70%依据拇收肌厚度被归类为营养不良。上臂肌围、上臂肌面积及去脂体重的数值与拇收肌厚度呈显著正相关（p<0.005）。拇收肌厚度同时与相位角及标准相位角呈正相关（相关系数r分别为0.49、0.31，对应p值分别<0.001与0.008）。
结论：以拇收肌厚度作为营养状态评估指标时，心力衰竭患者存在较高的蛋白质营养不良发生率。拇收肌厚度数值与躯体蛋白质评估的常规指标具有相关性，且由于其与相位角及标准相位角呈正相关，或可用于预测此类患者的预后。