Program for Pregnancy and Postpartum Health, University of Alberta, Edmonton, AB, Canada.
Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada.
Physiol Rep. 2020 Jul;8(13):e14504. doi: 10.14814/phy2.14504.
Gestational diabetes mellitus (GDM) is associated with vascular dysfunction. Sympathetic nervous system activity (SNA) is an important regulator of vascular function, and is influenced by glucose and insulin. The association between GDM and SNA (re)activity is unknown. We hypothesize that women with GDM would have increased SNA during baseline and during stress.
Eighteen women with GDM and 18 normoglycemic pregnant women (controls) were recruited. Muscle SNA (MSNA; peroneal microneurography) was assessed at rest, during a cold pressor test (CPT) and during peripheral chemoreflex deactivation (hyperoxia). Spontaneous sympathetic baroreflex gain was quantified versus diastolic pressure at rest and during hyperoxia.
Age, gestational age (third trimester) and pre-pregnancy body mass index and baseline MSNA was not different among the groups. Women with GDM had a similar increase in MSNA, but a greater pressor response to CPT compared to controls (% change in MAP 17 ± 7% vs. 9 ± 9%; p = .004). These data are consistent with a greater neurovascular transduction in GDM (% change in total peripheral resistance/% change in burst frequency [BF]: 15.9 ± 30.2 vs. -5.2 ± 16.4, p = .03). Interestingly, women with GDM had a greater reduction in MSNA during hyperoxia (% change in BF -30 ± 19% vs. -6 ± 17%; p = .01).
Women diagnosed with GDM have similar basal SNA versus normoglycemic pregnant women, but greater neurovascular transduction, meaning a greater influence of the sympathetic nerve activity in these women. We also document evidence of chemoreceptor hyperactivity, which may influence SNA in women with GDM but not in controls.
妊娠糖尿病（GDM）与血管功能障碍有关。交感神经系统活动（SNA）是血管功能的重要调节因素，受血糖和胰岛素的影响。GDM 与 SNA（再）活性之间的关系尚不清楚。我们假设 GDM 女性在基线和应激期间会增加 SNA。
招募了 18 名 GDM 女性和 18 名血糖正常的孕妇（对照组）。在静息、冷加压试验（CPT）和外周化学感受器失活（高氧）期间评估腓肠肌 SNA（peroneal microneurography）。在静息和高氧期间，定量测量自主交感神经血压反射增益与舒张压的关系。
三组间年龄、妊娠晚期（孕晚期）和孕前体重指数及基线 SNA 无差异。与对照组相比，GDM 女性的 SNA 增加相似，但 CPT 的血压升高反应更大（MAP 变化百分比 17±7%比 9±9%；p=0.004）。这些数据与 GDM 中更大的神经血管转导一致（总外周阻力变化百分比/爆发频率变化 [%]：15.9±30.2 比-5.2±16.4，p=0.03）。有趣的是，GDM 女性在高氧期间 SNA 下降幅度更大（BF 变化百分比-30±19%比-6±17%；p=0.01）。
与血糖正常的孕妇相比，诊断为 GDM 的女性 SNA 基础水平相似，但神经血管转导更大，这意味着这些女性的交感神经活动影响更大。我们还记录了化学感受器活性增加的证据，这可能会影响 GDM 女性的 SNA，但不会影响对照组女性的 SNA。
