Atherogenic lipoproteins can cause endothelial dysfunction in the initial stage of atherogenesis. In our study we examined 134 patients with defined hyperlipoproteinemia (non-HDL cholesterol > 4.1 mmol/l or triglycerides > 2.5 mmol/l or taking any of lipid lowering drugs) – 94 men and 40 women. The subgroup of controls of comparable age contained 54 normolipidemic individuals – 30 men and 24 women. Patients with hyperlipoproteinemia revealed significantly lower ability of endothelium-dependent flow-mediated vasodilation (EDV) measured on brachial artery (4.13±3.07 vs. 5.41±3.82 %; p=0.032) and higher carotid intima media thickness than normolipidemic controls (0.68±0.22 vs. 0.58±0.15 mm; p=0.005). In regression analysis, EDV correlated significantly with plasma concentrations of oxLDL (p<0.05) HDL-cholesterol (p<0.05), Apo A1 (p<0.05), ATI (p<0.01) and non-HDL cholesterol (p<0.05). Patients with hyperlipoproteinemia showed higher plasma levels of oxLDL (65.77±9.54 vs. 56.49±7.80 U/l; p=0.015), malondialdehyde (0.89±0.09 vs. 0.73±0.08 µmol/l; p=0.010) and nitrites/nitrates (20.42±4.88 vs. 16.37±4.44 µmol/l; p=0.018) indicating possible higher long-term oxidative stress in these patients.
A personalized antidiabetic therapy is not yet part of the official guidelines of professional societies for clinical practice. The aim of this study was to evaluate the serum C-peptide and plasma glucose levels in patients with type 2 diabetes mellitus (T2DM) after oral administration of whey proteins. Sixteen overweight T2DM Caucasians with good glycemic control and with preserved fasting serum C-peptide levels (>200 nmol/l) were enrolled in this study. Two oral stimulation tests – one with 75 g of glucose (OGTT) and the other with 75 g of whey proteins (OWIST) – were administered for assessing serum C-peptide and plasma glucose levels in each participant. Both oral tests induced similar pattern of C-peptide secretion, with a peak at 90 min. The serum C-peptide peak concentration was 2.91±0.27 nmol/l in OWIST, which was 22 % lower than in OGTT. Similarly, the C-peptide iAUC0-180 were 32 % lower in the OWIST than in the OGTT (p<0.01). Contrary to OGTT the OWIST did not cause a significant increase of glycemia (p<0.01). Our study showed that the OWIST represents a useful tool in estimation of stimulated serum C-peptide levels in patients with T2DM.