Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Cardiovasc Diabetol. 2021 Apr 24;20(1):87. doi: 10.1186/s12933-021-01278-7.
Left ventricular (LV) longitudinal myocardial dysfunction is considered a marker of preclinical LV dysfunction in patients with type 2 diabetes mellitus (T2DM). High heart rate (HR) is associated with cardiovascular outcomes, but the effect of HR on LV longitudinal myocardial function in T2DM patients is uncertain.
We studied 192 T2DM patients with preserved LV ejection fraction (LVEF), and 81 age-, sex-, and LVEF-matched healthy volunteers. HR was measured as the average HR during echocardiography, and high HR was defined as resting HR ≥ 70 beats/minute. LV longitudinal myocardial function was assessed as global longitudinal strain (GLS). The predefined cutoff for subclinical LV dysfunction was set at GLS < 18%.
GLS in T2DM patients with high HR was significantly lower than that in T2DM patients with low HR (16.3% ± 4.2% vs. 17.8% ± 2.8%; P = 0.03), whereas GLS in normal subjects with high and low HR was similar (20.3 ± 1.7% vs. 20.3 ± 2.0%; P = 0.99). Multivariable logistic regression analysis showed that high HR (odds ratio: 1.04; 95% confidence interval: 1.01-1.07; P = 0.01) was independently associated with GLS < 18% in T2DM patients as well as HbA1c, T2DM duration, LVEF, body mass index, and mitral inflow E and mitral e' annular velocity ratio. One sequential logistic model evaluating the associations between GLS < 18% and clinical variables in T2DM patients showed an improvement with the addition of LVEF and E/e' (P < 0.001) and a further improvement with the addition of high HR (P < 0.001).
Compared with normal subjects, resting HR was associated with LV longitudinal myocardial function in asymptomatic T2DM patients with preserved LVEF. Our findings provide new insights on the management of T2DM patients.
左心室（LV）纵向心肌功能障碍被认为是 2 型糖尿病（T2DM）患者临床前 LV 功能障碍的标志物。高心率（HR）与心血管结局相关，但 HR 对 T2DM 患者 LV 纵向心肌功能的影响尚不确定。
我们研究了 192 例射血分数保留的 T2DM 患者和 81 名年龄、性别和射血分数匹配的健康志愿者。HR 作为超声心动图期间的平均 HR 进行测量，高 HR 定义为静息 HR≥70 次/分钟。LV 纵向心肌功能评估为整体纵向应变（GLS）。亚临床 LV 功能障碍的预设截断值设定为 GLS<18%。
HR 较高的 T2DM 患者的 GLS 明显低于 HR 较低的 T2DM 患者（16.3%±4.2% vs. 17.8%±2.8%；P=0.03），而 HR 较高和较低的正常受试者的 GLS 相似（20.3%±1.7% vs. 20.3%±2.0%；P=0.99）。多变量逻辑回归分析显示，高 HR（比值比：1.04；95%置信区间：1.01-1.07；P=0.01）与 T2DM 患者 GLS<18%以及 HbA1c、T2DM 病程、LVEF、体重指数和二尖瓣流入 E 和二尖瓣 e'环速度比独立相关。一个评估 T2DM 患者 GLS<18%与临床变量之间关联的连续逻辑模型显示，随着 LVEF 和 E/e'的增加（P<0.001）而得到改善，并随着高 HR 的增加（P<0.001）而进一步改善。
与正常受试者相比，无症状射血分数保留的 T2DM 患者静息 HR 与 LV 纵向心肌功能相关。我们的研究结果为 T2DM 患者的管理提供了新的见解。
