Table5_Body composition and mortality in a cohort study of Chinese patients with hypertrophic cardiomyopathy.xlsx

ObjectiveTo analyse the characteristics and mortality of hypertrophic cardiomyopathy (HCM) patients with different body compositions.
MethodsIn this study, 530 consecutive patients with HCM at West China Hospital were studied from November 2008 to May 2016. An equation based on body mass index (BMI) was used to obtain the Percent body fat (BF) and lean mass index (LMI). Patients were divided into five sex-specific BMI, BF and LMI quintiles.
ResultsThe average BMI, BF and LMI were 23.1 ± 3.2 kg/m2, 28.1 ± 7.3% and 16.5 ± 2.2 kg/m2, respectively. Patients with higher BMI or BF were older and had more symptoms and adverse cardiovascular conditions; those with higher LMI were younger and had less coronary artery disease and lower serum NT-proBNP and creatine. BF correlated positively with resting left ventricular (LV) outflow tract gradient, mitral regurgitation (MR) degree and left atrial diameter but was inversely associated with septal wall thickness (SWT), posterior wall thickness (PWT), LV mass, and E/A ratio; LMI was positively correlated with SWT, LV end diastolic volume and LV mass but was negatively associated with MR degree.48 all-cause deaths occurred during a median follow-up of 33.8 months. Reversed J-shape associations of BMI and LMI with mortality were observed. A lower BMI or LMI was significantly associated with high mortality, especially for low-moderate BMI and LMI. No significant difference in mortality was found across BF quintiles.
ConclusionsThe associations of BMI, BF and LMI with baseline characteristics and cardiac remodelling are different in HCM patients. In Chinese HCM patients, low BMI and LMI predicted mortality but not BF.

目的：分析不同身体成分的肥厚型心肌病（Hypertrophic Cardiomyopathy, HCM）患者的临床特征与死亡率情况。
方法：本研究纳入2008年11月至2016年5月于华西医院就诊的530例连续性肥厚型心肌病患者。基于体重指数（Body Mass Index, BMI）推导公式，计算受试者的体脂百分比（Body Fat Percent, BF）与瘦体重指数（Lean Mass Index, LMI）。按性别分层，将患者按BMI、BF及LMI分为五个五分位数组。
结果：本研究队列的平均BMI、BF及LMI分别为23.1±3.2 kg/m²、28.1±7.3%及16.5±2.2 kg/m²。较高BMI或BF的患者年龄更大，临床症状更显著，合并心血管不良事件的比例更高；而较高LMI的患者年龄更轻，冠状动脉疾病患病率更低，血清N末端B型利钠肽原（NT-proBNP）与肌酐水平也更低。体脂百分比（BF）与静息状态左心室（Left Ventricular, LV）流出道压力阶差、二尖瓣反流（Mitral Regurgitation, MR）程度及左心房内径呈正相关，却与室间隔厚度（Septal Wall Thickness, SWT）、后壁厚度（Posterior Wall Thickness, PWT）、左心室质量及E/A比值呈负相关；瘦体重指数（LMI）则与室间隔厚度、左心室舒张末期容积及左心室质量呈正相关，与二尖瓣反流程度呈负相关。本研究中位随访时长为33.8个月，期间共发生48例全因死亡事件。观察到BMI与LMI与死亡率呈倒J型关联：较低的BMI或LMI均与较高的死亡率显著相关，尤其在低-中度BMI及LMI亚组中更为明显。不同体脂百分比五分位数组间的死亡率无显著差异。
结论：肥厚型心肌病患者中，BMI、BF及LMI与基线临床特征及心脏重构的关联存在差异。在中国肥厚型心肌病患者群体中，较低的BMI与LMI可预测不良死亡结局，而体脂百分比则无此预测价值。