The use of spontaneous bursts of muscle sympathetic nerve activity (MSNA) to assess arterial baroreflex control of sympathetic nerve activity has seen increased utility in studies of both health and disease. However, methods used for analyzing spontaneous MSNA baroreflex sensitivity are highly variable across published studies. Therefore, we sought to comprehensively examine methods of producing linear regression slopes to quantify spontaneous MSNA baroreflex sensitivity in a large cohort of subjects (n=150) to support a standardized procedure for analysis that would allow for consistent and comparable results across laboratories. The primary results demonstrated that 1) consistency of linear regression slopes was considerably improved when the correlation coefficient was above -0.70, which is more stringent compared with commonly reported criterion of -0.50, 2) longer recording durations increased the percentage of linear regressions producing correlation coefficients above -0.70 (1-min:15%, 2-min:28%, 5-min:53%, 10-min:67%, P<0.001) and reaching statistical significance (1-min:40%, 2-min:69%, 5-min:78%, 10-min:89%, P<0.001), 3) correlation coefficients were improved with 3-mmHg diastolic BP bin size vs. 1- and 2-mmHg, and 4) linear regression slopes were reduced when the acquired blood pressure (BP) signal was not properly aligned with the cardiac cycle triggering the burst of MSNA. In summary, these results support the use of baseline recording durations of 10 min, a correlation coefficient above -0.70 for reliable linear regressions, 3-mmHg bin size, and importance of properly time aligning MSNA and diastolic BP. Together, these findings provide best practices for determining spontaneous MSNA baroreflex sensitivity under resting conditions for improved rigor and reproducibility of results.

中文翻译：

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评估人类肌肉交感神经活动自发压力反射控制的标准化方法


使用肌肉交感神经活动的自发爆发（MSNA）来评估交感神经活动的动脉压力感受反射控制在健康和疾病研究中的实用性不断增加。然而，在已发表的研究中，用于分析自发性 MSNA 压力反射敏感性的方法差异很大。因此，我们试图全面检查产生线性回归斜率的方法，以量化一大群受试者 (n=150) 中自发的 MSNA 压力反射敏感性，以支持标准化的分析程序，从而在各个实验室获得一致和可比的结果。主要结果表明，1) 当相关系数高于 -0.70 时，线性回归斜率的一致性得到显着改善，这比通常报告的 -0.50 标准更为严格，2) 较长的记录持续时间增加了产生相关性的线性回归的百分比系数高于-0.70（1分钟：15％，2分钟：28％，5分钟：53％，10分钟：67％，P<0.001）并达到统计显着性（1分钟：40％，2 -min:69%, 5-min:78%, 10-min:89%, P<0.001), 3) 与 1- 和 2-mmHg 相比，3-mmHg 舒张压箱尺寸的相关系数得到改善，4当获取的血压 (BP) 信号与触发 MSNA 突发的心动周期不正确对齐时，线性回归斜率会降低。总之，这些结果支持使用 10 分钟的基线记录持续时间、可靠的线性回归高于 -0.70 的相关系数、3-mmHg 箱大小以及正确调整 MSNA 和舒张压时间的重要性。 总之，这些发现提供了在静息条件下确定自发 MSNA 压力反射敏感性的最佳实践，以提高结果的严谨性和可重复性。