Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, Oulu Center for Cell-Matrix Research, University of Oulu, Oulu, Finland.
Medical Research Center Oulu, Faculty of Medicine, Oulu University Hospital and Research Unit of Internal Medicine, University of Oulu, Oulu, Finland.
Am J Physiol Heart Circ Physiol. 2023 Oct 1;325(4):H629-H634. doi: 10.1152/ajpheart.00415.2023. Epub 2023 Aug 11.
The aim of this study was to cross-sectionally examine whether hemoglobin (Hb) levels within the normal variation associate with heart rate variability (HRV) measures and baroreflex sensitivity (BRS). The study population included 733 Finnish subjects of the OPERA cohort (aged 41-59 yr, 53% males, 51.7% treated for hypertension) of whom HRV was measured from a standardized 45-min period and whose Hb levels were within the Finnish reference intervals. The low Hb tertile (mean Hb, 135 g/L) had an overall healthier metabolic profile compared with the high Hb tertile (mean Hb, 152 g/L). BRS was higher in the low Hb tertile compared with the high Hb tertile ( < 0.05). R-R interval (RRi) and standard deviation (SD) of the RRi (SDNN)index were the longest in the low Hb tertile regardless of posture. Of the spectral components of HRV, HF power was the highest in the low Hb tertile regardless of posture ( < 0.05). In a stepwise logistic regression model, BRS associated negatively with Hb levels after adjusting for covariates ( = -0.160 [-0.285; -0.035]). Similar associations were observed for SDNNindex when lying down ( = -0.105 [-0.207; -0.003]) and walking ( = -0.154 [-0.224; -0.083]). For HF power negative associations with Hb levels were observed when lying down ( = -0.110 [-0.180; -0.040]), sitting ( = -0.150 [-0.221; -0.079]), and in total analysis ( = -0.124 [-0.196; -0.053]). Overall, lower Hb levels associated independently with healthier cardiac autonomic function. Heart rate variability (HRV) and baroreflex sensitivity (BRS), which can be measured noninvasively, can predict cardiac and metabolic diseases. Our findings show that within normal variation subjects with lower hemoglobin (Hb) levels have an overall healthier HRV profile and increased cardiac parasympathetic activity in middle age, independent of age, sex, smoking status, and key metabolic covariates. These findings support our previous findings that Hb levels can be used in assessing long-term risks for cardiometabolic diseases.
本研究旨在横截面上探讨正常范围内的血红蛋白（Hb）水平是否与心率变异性（HRV）和压力反射敏感性（BRS）相关。研究人群包括来自 OPERA 队列的 733 名芬兰受试者（年龄 41-59 岁，男性占 53%，51.7%患有高血压），他们的 HRV 是从标准化的 45 分钟期间测量的，且 Hb 水平处于芬兰参考区间内。与高 Hb 三分位组（平均 Hb 为 152g/L）相比，低 Hb 三分位组（平均 Hb 为 135g/L）整体代谢指标更健康。与高 Hb 三分位组相比，低 Hb 三分位组的 BRS 更高（<0.05）。无论体位如何，低 Hb 三分位组的 R-R 间期（RRi）和 R-Ri 的标准差（SDNN）指数最长。无论体位如何，HRV 的频谱成分中，低 Hb 三分位组的高频功率（HF 功率）最高（<0.05）。在逐步逻辑回归模型中，调整协变量后，BRS 与 Hb 水平呈负相关（=-0.160[-0.285；-0.035]）。当受试者处于卧位和行走位时，SDNN 指数也存在类似的关联（卧位：=-0.105[-0.207；-0.003]；行走位：=-0.154[-0.224；-0.083]）。当受试者处于卧位、坐位和总分析时，与 Hb 水平呈负相关的 HF 功率也存在类似的关联（卧位：=-0.110[-0.180；-0.040]；坐位：=-0.150[-0.221；-0.079]；总分析：=-0.124[-0.196；-0.053]）。总的来说，较低的 Hb 水平与更健康的心脏自主神经功能独立相关。可以非侵入性测量的心率变异性（HRV）和压力反射敏感性（BRS）可以预测心脏和代谢疾病。我们的研究结果表明，在正常范围内，Hb 水平较低的个体在中年时具有整体更健康的 HRV 特征，且心脏副交感神经活动增强，这与年龄、性别、吸烟状况和主要代谢协变量无关。这些发现支持我们之前的研究结果，即 Hb 水平可用于评估心脏代谢疾病的长期风险。
