Department of Geriatrics, West China Hospital, West China Medical Hospital of Sichuan University, Chengdu, Sichuan 610041, China.
Chin Med J (Engl). 2010 Dec;123(24):3640-3.
The development of diabetic cardiomyopathy is multifactorial. Insulin resistance (IR) and excessive activity of the renin-angiotensin system are confirmed reasons for diabetic cardiomyopathy. Renin-angiotensin system (RAS) inhibitors can reduce tissue Ang II levels, with beneficial effects on cardiovascular function. Therefore, in type-2 diabetes mellitus (T2DM), blockade of the RAS may have the function of protecting against diabetic cardiomyopathy through increasing insulin sensitivity and inhibiting excessive activity of RAS. However, this has not been confirmed.
The effect of valsartan, an angiotensin receptor blocker (ARB), on diabetic cardiomyopathy in the presence of T2DM was studied. Wistar rats with T2DM and T2DM treated with valsartan were studied. Glucose infusion rates (GIR), index of IR, heart weight, the heart weight-to-body weight ratio (HW/BW), myocardial apoptotic index, cardiac hydroxyprolin content, and cardiac tissue collagen type I and collagen type III content were measured.
GIR in T2DM rats and T2DM rats treated with valsartan decreased (P < 0.01). In T2DM rats treated with valsartan, heart weight, myocardial apoptotic index, cardiac hydroxyprolin content, and cardiac tissue collagen type I and collagen type III content were higher than in control rats, but lower than in T2DM rats. In rats with T2DM, GIR was negatively and significantly correlated with all the variables. However, in T2DM rats treated with valsartan or normal control rats, none of the correlations was significant.
In the presence of T2DM, diabetic cardiomyopathy is related with IR. Valsartan can not alleviate IR, but can protect against diabetic cardiomyopathy and remove the correlation between IR and diabetic cardiomyopathy.
糖尿病性心肌病的发生发展是多因素的。胰岛素抵抗（IR）和肾素-血管紧张素系统（RAS）过度激活被证实是糖尿病性心肌病的原因。RAS 抑制剂可降低组织 Ang II 水平，对心血管功能有益。因此，在 2 型糖尿病（T2DM）中，通过增加胰岛素敏感性和抑制 RAS 的过度激活，阻断 RAS 可能具有预防糖尿病性心肌病的作用。然而，这一点尚未得到证实。
研究了血管紧张素受体阻滞剂（ARB）缬沙坦在 T2DM 存在时对糖尿病性心肌病的影响。研究了 T2DM 大鼠和 T2DM 大鼠经缬沙坦治疗后的葡萄糖输注率（GIR）、IR 指数、心脏重量、心脏重量/体重比（HW/BW）、心肌凋亡指数、心肌羟脯氨酸含量以及心肌组织 I 型和 III 型胶原含量。
T2DM 大鼠和 T2DM 大鼠经缬沙坦治疗后的 GIR 降低（P<0.01）。缬沙坦治疗的 T2DM 大鼠的心脏重量、心肌凋亡指数、心肌羟脯氨酸含量和心肌组织 I 型和 III 型胶原含量均高于对照组，但低于 T2DM 大鼠。在 T2DM 大鼠中，GIR 与所有变量均呈负显著相关。然而，在 T2DM 大鼠经缬沙坦治疗或正常对照组大鼠中，均无相关性。
在 T2DM 存在的情况下，糖尿病性心肌病与 IR 有关。缬沙坦不能缓解 IR，但能预防糖尿病性心肌病，并消除 IR 与糖尿病性心肌病之间的相关性。
