Relationship between Lipid Indices, Type IV Collagen Turnover and the Development of Microvascular Complications in Diabetic Patients with Arterial Hypertension

Background and aims: An important factor in the development of vascular wall lesions is the degradation of the major protein of connective tissue - type IV collagen. Type IV collagen peptides (CIVDP) derived from this degradation are present in the circulation and are a stimulus for production of anti-collagen type IV antibodies (ACIVAbs) IgM, IgG and IgA. The aim of this study was to find a possible association between ACIVAbs, lipid indices and the development of microvascular complications. Materials and methods: Sera of 93 patients (mean age 61.4±11.3 yrs, diabetes duration 9.88±3.12 yrs; hypertension duration 9.28±4.98) with type 2 diabetes mellitus (T2DM) and arterial hypertension (AH) were investigated. ACIVAbs was determined using ELISA and then compared to serum ACIVAbs in 42 age- and sex-matched controls. Diabetics were divided into two groups according to presence (group 1, n=67) or absence (group 2, n=26) of microangiopathy. Lipid profile and lipid indices (log TG/HDL, LDL/HDL, TC/HDL and TG/HDL) were examined too. Results: Patients with T2DM and AH showed statistically significant higher levels of serum ACIVAbs IgG than healthy controls [0.298 (0.237÷0.381) vs 0.210 (0.149÷0.262), KW=14.01, p<0.0001]. Group 1 had statistically significant higher levels of ACIVAbs IgG than patients without microangiopathy [0.323 (0.243÷0.391) vs 0.241 (0.207÷0.291), KW=7.66, p=0.006] and healthy controls [0.210 (0.149÷0.262), KW=17.52, p<0.0001). ACIVAbs IgG showed correlation with duration of diabetes (r=0.49, p=0.01), retinopathy (r=−0.20, p=0.04) and BMI (r=−0.24, p=0.05), HbA1c (r=0.21, p=0.04), SBP (r=0.16, p=0.05). ACIVAbs IgG correlated with log TG/HDL (r=0.21, p=0.01), LDL/HDL (r=0.19, p=0.02) TC/HDL (r=0.16, p=0.05) and with TG/HDL (r=0.15, p=0.05). Conclusion: Our study shows relationship between elevation of ACIVAbs IgG, high lipid indices and development of microvascular complications in patients with type 2 diabetes mellitus and arterial hypertension.