Background:Obesity is common in heart failure with preserved ejection fraction (HFpEF), and a hypocaloric diet can improve functional capacity. Malnutrition, sarcopenia, and frailty are also frequently present, and calorie restriction could harm some patients. Resting metabolic rate (RMR) is an essential determinant of caloric needs; however, it is rarely measured in clinical practice. The accuracy of commonly used predictive equations in HFpEF is unknown.Methods:RMR was measured with indirect calorimetry in 43 patients with HFpEF undergoing right heart catheterization at the University of Michigan, and among 49 participants in the SECRET trial (Study of the Effects of Caloric Restriction and Exercise Training in Patients With Heart Failure and a Normal Ejection Fraction); SECRET patients also had dual-energy X-ray absorptiometry body composition measures. Measured RMR was compared with RMR estimated using the Harris Benedict, Mifflin-St Jeor, World Health Organization, and Academy for Nutrition and Dietetics equations.Results:All predictive equations overestimated RMR (by >10%, P<0.001 for all), with mean (95% CI) differences Harris Benedict equation +250 (186–313), Mifflin-St. Jeor equation +169 (110–229), World Health Organization equation +300 (239–361), and Academy for Nutrition and Dietetics equation +794 (890–697) kcal/day. Results were similar across both patient groups, and the discrepancy between measured and estimated RMR tended to increase with body mass index. In SECRET, measured RMR was closely associated with lean body mass (ρ=0.74; by linear regression adjusted for age and sex: β=27 [95% CI, 18–36] kcal/day per kg, P<0.001; r²=0.56).Conclusions:Commonly used predictive equations systematically overestimate measured RMR in patients with HFpEF. Direct measurement of RMR may be needed to effectively tailor dietary guidance in this population.Registration:URL: https://www.clinicaltrials.gov; Unique Identifier: NCT00959660.

中文翻译：

---

在保留射血分数的心力衰竭中测量与估计的静息代谢率

背景：肥胖在射血分数保留型心力衰竭（HFpEF）中很常见，低热量饮食可以提高功能能力。营养不良、肌肉减少和虚弱也经常出现，限制卡路里摄入可能会伤害一些患者。静息代谢率 (RMR) 是热量需求的重要决定因素；然而，它在临床实践中很少被测量。HFpEF 中常用预测方程的准确性尚不清楚。方法：在密歇根大学接受右心导管插入术的 43 名 HFpEF 患者和 SECRET 试验（热量影响研究的研究）的 49 名参与者中，使用间接量热法测量 RMR心力衰竭和射血分数正常患者的限制和运动训练）；SECRET 患者还进行了双能 X 射线骨密度仪身体成分测量。将测量的 RMR 与使用 Harris Benedict、Mifflin-St Jeor、世界卫生组织和营养与饮食学会方程估计的 RMR 进行比较。结果：所有预测方程都高估了 RMR（>10%，所有P <0.001），平均 (95% CI) 差异 Harris Benedict 方程 +250 (186–313)，Mifflin-St. Jeor 方程 +169 (110–229)、世界卫生组织方程 +300 (239–361) 和营养与饮食学会方程 +794 (890–697) kcal/天。两组患者的结果相似，测量和估计的 RMR 之间的差异倾向于随着体重指数的增加而增加。在 SECRET 中，测量的 RMR 与瘦体重密切相关（ρ=0.74；通过针对年龄和性别调整的线性回归：β=27 [95% CI，18-36] kcal/day/kg，P <0.001；r ²=0.56)。结论：常用的预测方程系统地高估了 HFpEF 患者测量的 RMR。可能需要直接测量 RMR 以有效调整该人群的饮食指导。注册：URL：https://www.clinicaltrials.gov；唯一标识符：NCT00959660。