Vigilance, J; Reid, Harvey .L; Wright-Pascoe, Rosemarie A; Choo-Kang, Eric
Insulin resistance, Inflammatory Markers, and Vascular Function in Type 2 Diabetes Mellitus
Journal of Vascular Research
Date of Publication
Chronic activation of the immune system may be involved in the aetiology and pathogenesis of type 2 diabetes mellitus and be further exacerbated by insulin resistance. This may influence vascular function. We examined the association between insulin resistance, inflammatory markers, and vascular function in type 2 diabetic patients. Measurements of blood glucose, plasma insulin, Interleukins-6 [IL-6] and 8 [IL-8] and white blood cell [WBC] differential counts were done on fasting blood samples in 44 type 2 diabetic patients [D] and 37 nondiabetic subjects [C]. Ankle blood flow [Qak] was measured at rest and during reactive hyperaemia by venous occlusion plethysmography. Vasodilatory reserve [VDR], a percentage increase in blood flow after reactive hyperaemia, was used as an indicator of vascular function. Homeostatic model assessment [HOMA-IR] was used to indicate insulin resistance [IR]. VDR and IL-8 were lower and IL-6 higher in D than in C [p < 0.05]. A high IR in D was associated with elevated WBC, Granulocyte count and IL-6 concentration and low VDR [p < 0.05]. The percentage of monocytes and lymphocytes were higher in D with low IR than in C or in D with high IR [p < 0.05]. Lymphocyte number correlated with VDR [r = -0.334], IL-6 with HOMA-IR [r = 0.520] and number of neutrophils [r = 0.593] and IL-8 with Qak [r = 0.389] in D [p < 0.05]. In conclusion, insulin resistance influenced WBC production and differentiation and the production of IL-6 and IL-8. However, it is unclear whether these interleukins directly affect vascular function in type 2 diabetes mellitus. Insulin resistance may however, have a role in vascular dysfunction in type 2 diabetic patients.....