Poirier Paul, Hernandez Teri L, Weil Kathleen M, Shepard Trudy J, Eckel Robert H
Division of Endocrinology, Metabolism, and Diabetes, University of Colorado Health Sciences Center, Denver, Colorado, USA.
Obes Res. 2003 Sep;11(9):1040-7. doi: 10.1038/oby.2003.143.
To determine the impact of diet-induced weight loss on cardiac autonomic nervous system modulation and arrhythmias in subjects with severe obesity and the influence of a high-fat or a high-carbohydrate diet regimen on heart rate variability in reduced-obese individuals.
Eight severely obese subjects (BMI > or = 40.0 kg/m(2)) underwent a 3-month weight loss program followed by a 3-month reduced-weight maintenance regimen. Thereafter, each subject was admitted for an inpatient period of 17 days on two separate occasions. A high-carbohydrate (60%) or high-fat (55%) diet of appropriate energy content for weight maintenance was prescribed during each inpatient phase. Heart rate variability was derived from a 24-hour Holter monitoring system in all subjects during their inpatient stay. Cardiac Holter monitoring was performed at three occasions (baseline, diet phase I, and diet phase II), including the second night of a two overnight calorimetry chamber stay.
After the diet regimen, there was a 10% decrease in weight. There were no significant changes in systolic and diastolic blood pressure, arrhythmias, glucose, insulin, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, respiratory exchange ratio, and resting energy expenditure between experiments. Mean heart rate was lower after weight loss compared with baseline (p < 0.001). After weight loss, there was an increase in the parasympathetic indices of heart rate variability showing an increase in cardiac vagal modulation (all p < 0.05).
Weight loss is associated with significant improvement in autonomic cardiac modulation through enhancement of parasympathetic modulation, which clinically translates into a decrease in heart rate.
确定饮食诱导的体重减轻对重度肥胖受试者心脏自主神经系统调节和心律失常的影响，以及高脂或高碳水化合物饮食方案对体重减轻后的肥胖个体心率变异性的影响。
八名重度肥胖受试者（体重指数≥40.0kg/m²）接受了为期3个月的体重减轻计划，随后是为期3个月的体重维持计划。此后，每位受试者分两次住院17天。在每个住院阶段，规定摄入能量适宜以维持体重的高碳水化合物（60%）或高脂肪（55%）饮食。所有受试者在住院期间通过24小时动态心电图监测系统获取心率变异性。在三个时间点（基线、饮食阶段I和饮食阶段II）进行心脏动态心电图监测，包括在两个过夜的热量测定室停留的第二个晚上。
饮食方案实施后，体重下降了10%。实验之间收缩压、舒张压、心律失常、血糖、胰岛素、总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、呼吸交换率和静息能量消耗均无显著变化。与基线相比，体重减轻后平均心率较低（p<0.001）。体重减轻后，心率变异性的副交感神经指标增加，表明心脏迷走神经调节增强（所有p<0.05）。
体重减轻与通过增强副交感神经调节使自主心脏调节显著改善有关，这在临床上表现为心率降低。
