Service de Cardiologie, Département Coeur-Vaisseaux, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
Service d'Endocrinologie, Diabétologie et Métabolisme, Département de Médecine, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
ESC Heart Fail. 2022 Feb;9(1):122-132. doi: 10.1002/ehf2.13642. Epub 2021 Dec 2.
Maximal exercise capacity as measured by peak oxygen consumption (pVO ) in cardiopulmonary exercise testing (CPET) of heart transplant recipients (HTR) is limited to a 50-70% level of healthy age-matched controls. This study investigated the relationship between body composition and pVO during the first decade post-transplant.
Body composition was determined by dual-energy X-ray absorptiometry (DXA) and pVO by CPET in 48 HTR (n = 38 males; mean age 51 ± 12 years). A total of 95 assessments were acquired 1-9 years post-transplant, and the results of four consecutive periods were compared [Period 1: 1-2 years (n = 25); 2: 3-4 years (n = 23); 3: 5-6 years (n = 23); 4: 7-9 years (n = 24)]. Linear regression analysis analysed the correlation between pVO and pairs of appendicular lean mass (ALM) and fat mass (FM). The relation between ALM and daily dose of calcineurin inhibitor (CNI) was explored using partial correlation controlling for age, gender, and height. pVO increased from 0.98 (0.34) to 1.35 (0.35) L/min (P < 0.01) between Periods 1 and 4 corresponding to 54.5-63.3% of predicted value. Peak heart rate (HR) raised from 115 ± 19 to 131 ± 23 b.p.m. (P = 0.05), and anaerobic threshold (AT = VO achieved at AT) increased from 0.57 (0.18) to 0.83 (0.35) L/min (P < 0.01) between Periods 1 and 3. Median FM normalized to height (FMI) always remained elevated (>8.8 kg/m ). ALM normalized to body mass index increased from 0.690 (0.188) to 0.848 (0.204) m (P = 0.02) between Periods 1 and 4, explaining 45% of the variance of pVO (R = 0.455; P < 0.001). Eighty-one per cent of the variance of pVO (R = 0.817; P < 0.001) in multiple regression was explained by AT (β = 0.488), ALM (β = 0.396), peak HR (β = 0.366), and FMI (β = -0.181). ALM was negatively correlated with daily CNI dose (partial R = -0.258; P = 0.01).
After heart transplantation, the beneficial effect of peripheral skeletal muscle gain on pVO is opposed by increased FM. Our findings support lifestyle efforts to fight adiposity and CNI dose reduction in the chronic stable phase to favour positive adaptation of peripheral muscle mass.
心肺运动测试（CPET）中测量的峰值耗氧量（pVO ）是心脏移植受者（HTR）最大运动能力的指标，其值限制在健康同龄对照的 50-70%水平。本研究旨在调查移植后最初十年内身体成分与 pVO 之间的关系。
48 例 HTR（n=38 名男性；平均年龄 51±12 岁）通过双能 X 射线吸收法（DXA）和 CPET 确定身体成分，共获得 95 次移植后 1-9 年的评估结果，比较了四个连续时期的结果[时期 1：1-2 年（n=25）；2：3-4 年（n=23）；3：5-6 年（n=23）；4：7-9 年（n=24）]。线性回归分析分析了 pVO 与四肢瘦体重（ALM）和脂肪量（FM）对的相关性。使用部分相关分析，控制年龄、性别和身高，探讨了 ALM 与钙调神经磷酸酶抑制剂（CNI）日剂量之间的关系。在第 1 期和第 4 期之间，pVO 从 0.98（0.34）增加到 1.35（0.35）L/min（P<0.01），对应预测值的 54.5-63.3%。最大心率（HR）从 115±19 增加到 131±23 b.p.m.（P=0.05），无氧阈（AT=在 AT 时达到的 VO）从 0.57（0.18）增加到 0.83（0.35）L/min（P<0.01）。第 1 期和第 3 期之间，身体质量指数标准化的 FM（FMI）始终保持升高（>8.8kg/m ）。BMI 标准化的 ALM 从 0.690（0.188）增加到 0.848（0.204）m（P=0.02），在第 1 期和第 4 期之间，解释了 pVO 变化的 45%（R 2 =0.455；P<0.001）。多元回归中，pVO 变化的 81%（R 2 =0.817；P<0.001）由 AT（β=0.488）、ALM（β=0.396）、最大 HR（β=0.366）和 FMI（β=-0.181）解释。ALM 与每日 CNI 剂量呈负相关（部分 R 2 =-0.258；P=0.01）。
心脏移植后，外周骨骼肌增加对 pVO 的有益影响被增加的 FM 所抵消。我们的研究结果支持生活方式的努力，以对抗肥胖症，并在慢性稳定期减少 CNI 剂量，以促进外周肌肉质量的积极适应。
