Autonomic dysfunction, in particular under-regulation of heart rate (HR) by the baroreflex, is implicated in development of insulin resistance (IR). According to reactivity hypothesis, sympathetic response to stressors may be more sensitive at predicting IR than baroreceptor sensitivity (BRS), a baseline measure of baroreflex functioning. Using ecological momentary assessment (EMA) of negative affect coupled with minute-to-minute HR and heart-rate variability (HRV) monitoring, we examined whether negative affect (NA)-related autonomic arousal mediates the association of BRS with IR. At baseline, BRS was measured, and fasting serum glucose and insulin levels were collected from 178 young adults (18-39 years old), from which homeostasis model assessment of IR (HOMA-IR) and beta-cell functioning (HOMA %B) were derived. Participants subsequently underwent one day of Holter HR and HRV monitoring while reporting negative affect levels via EMA. Multilevel modeling was used to assess the associations of momentary negative affect with HR and low- (LF) and high-frequency (HF) HRV during the 5-minute intervals following each EMA reading. Structural equation modeling was then used to determine whether individual differences in these associations mediated the association of BRS with IR, measured by HOMA-IR, HOMA %B, and insulin levels. As predicted, BRS was negatively associated with the IR (β = -.17, p = .024). However, NA-related autonomic arousal mediated their association, accounting for 56% of the covariance between BRS and IR. Not only do these results provide support for reactivity hypothesis, they reveal a potential point of intervention in the treatment of affective dysregulation.

中文翻译：

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负面影响相关的自主神经调节介导非糖尿病年轻成年人的压力反射功能障碍和胰岛素抵抗之间的关联。

自主神经功能紊乱，特别是压力反射引起的心律（HR）调节不足，与胰岛素抵抗（IR）的发展有关。根据反应性假设，对压力源的交感反应在预测IR方面可能比压力感受器敏感性（BRS）（压力反射功能的基线量度）更敏感。使用负面影响的生态瞬时评估（EMA）以及每分钟的HR和心率变异性（HRV）监测，我们检查了负面影响（NA）相关的自主唤醒是否介导了BRS与IR的关联。在基线时，测量了BRS，并从178位年轻的成年人（18-39岁）中收集了空腹血糖和胰岛素水平，从中评估了IR（HOMA-IR）和β细胞功能（HOMA％B）的稳态模型被派生。参与者随后接受了Holter HR和HRV监测的一天，同时通过EMA报告了负面影响水平。在每次EMA读取后的5分钟间隔内，使用多级建模来评估瞬时负面影响与HR，低（LF）和高频（HF）HRV的关联。然后，使用结构方程模型确定这些关联中的个体差异是否介导了BRS与IR的关联（通过HOMA-IR，HOMA％B和胰岛素水平测量）。如预期的那样，BRS与IR呈负相关（β= -.17，p = .024）。但是，NA相关的自主唤醒介导了它们的关联，占BRS和IR之间协方差的56％。这些结果不仅为反应性假设提供了支持，