Prakash Kiran, Chandran Dinu S, Khadgawat Rajesh, Jaryal Ashok Kumar, Deepak Kishore K
Department of Physiology, All India Institute of Medical Sciences, New Delhi, India Department of Physiology, Government Medical College & Hospital, Chandigarh, India.
Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
Diab Vasc Dis Res. 2016 Jan;13(1):49-55. doi: 10.1177/1479164115604120. Epub 2015 Sep 25.
Insulin resistance is associated with endothelial dysfunction in type 2 diabetes mellitus, which can lead to impaired vascular reactivities of both systemic and cerebral circulations. Appropriate 'correction' of vascular reactivity results for non-endothelium-dependent systemic effects avoids misinterpretation of endothelial function. Therefore, we 'corrected' vascular reactivity results and explored the potential correlations between systemic vascular reactivity, cerebrovascular reactivity and insulin resistance. In 34 patients, 'systemic vascular reactivity' was assessed by quantifying reactive hyperaemia. Cerebrovascular reactivity was assessed by quantifying changes in cerebral blood flow velocity during hypercapnia. To minimize the influence of non-endothelium-dependent systemic effects on vascular reactivity results, 'corrected systemic vascular reactivity' was calculated by normalizing systemic vascular reactivity using the measurements from the contralateral side; and cerebrovascular reactivity results were corrected by calculating percentage and absolute changes in cerebrovascular conductance index ('percent cerebrovascular conductance index' and 'delta cerebrovascular conductance index', respectively). Insulin resistance was estimated by homeostatic model assessment. Correlation between conventional cerebrovascular reactivity and systemic vascular reactivity was not significant. But correlations between 'corrected systemic vascular reactivity' and 'percent cerebrovascular conductance index' (r = 0.51; p = 0.002) and 'corrected systemic vascular reactivity' and 'delta cerebrovascular conductance index' (r = 0.50; p = 0.003) were significant. Among all vascular reactivity parameters, only 'delta cerebrovascular conductance index' was significantly correlated with homeostatic model assessment of insulin resistance (r = -0.38; p = 0.029). In conclusion, endothelial function in the systemic and cerebral circulations is moderately correlated, provided that vascular reactivity estimates are corrected for non-endothelium-dependent influences.
胰岛素抵抗与2型糖尿病中的内皮功能障碍相关，这可导致全身和脑循环的血管反应性受损。对非内皮依赖性全身效应的血管反应性结果进行适当“校正”可避免对内皮功能的错误解读。因此，我们校正了血管反应性结果，并探讨了全身血管反应性、脑血管反应性与胰岛素抵抗之间的潜在相关性。在34例患者中，通过量化反应性充血来评估“全身血管反应性”。通过量化高碳酸血症期间脑血流速度的变化来评估脑血管反应性。为了尽量减少非内皮依赖性全身效应对血管反应性结果的影响，通过使用对侧测量值对全身血管反应性进行标准化来计算“校正后的全身血管反应性”；通过计算脑血管传导指数的百分比和绝对变化（分别为“脑血管传导指数百分比”和“脑血管传导指数差值”）来校正脑血管反应性结果。通过稳态模型评估来估计胰岛素抵抗。传统脑血管反应性与全身血管反应性之间的相关性不显著。但“校正后的全身血管反应性”与“脑血管传导指数百分比”（r = 0.51；p = 0.002）以及“校正后的全身血管反应性”与“脑血管传导指数差值”（r = 0.50；p = 0.003）之间的相关性显著。在所有血管反应性参数中，只有“脑血管传导指数差值”与胰岛素抵抗的稳态模型评估显著相关（r = -0.38；p = 0.029）。总之，在对非内皮依赖性影响进行血管反应性估计校正的情况下，全身和脑循环中的内皮功能存在中度相关性。
