Relative Analysis Of C-peptide Level And Small Vessel Disease

Objective: High insulin levels are a recognized risk factor for atherosclerosis. Compared to the large-vessel endothelium, the microvascular endothelium is more susceptible to the metabolic and mitogenic effects of insulin. Besides their atherogenic effect, high insulin levels also impair fibrinolysis by enhancing plasminogen activator inhibitor–1. This study aims to evaluate the hypothesis that elevated serum insulin and C-peptide levels are related to cerebral small-vessel disease rather than large-vessel pathology.Methods: One hundred and ninety four patients with symptomatic cerebrovascular disease acted as the study group, while thirty patients without symptoms of cerebrovascular disease were examined as the control group. The study group differentiated into three subgroups through clinical presentations, brain imaging studies, and extracranial as well as transcranial vascular ultrasound findings:(1) patients with lacunes(n=20),(2) patients with subcortical arteriosclerotic encephalopathy(n=35), and(3) patients with strokes due to large-vessel disease(n=69). Patients who had suffered a cryptogenic(n=3) or cardioembolic(n=7) stroke or who showed characteristics of the microangiopathy and macroangiopathy groups(n=15) were not further evaluated. Thirty patients without manifestations of cerebrovascular disease were also examined. All patients underwent examinations regulating: the fasting of blood glucose, insulin level, and C-peptide levels.Results: There were no significant differences in age or sex among the three groups and control patients. C-peptide levels were significantly higher in the lacunar group compared with the subcortical arteriosclerotic encephalopathy group, the macroangiopathy group, and the control patients(median [interquartile range]: 1.5 [0.97], 0.9 [0.46], 0.87 [0.46], and 0.7 [0.43] pmol/ml, respectively; all P<0.05, Mann-Whitney test). There was a statistically significant difference in C-peptide concentrations between the microangiopathy group(subcortical arteriosclerotic encephalopathy and lacunes) and the macroangiopathy and control groups(0.98 [0.7], 0.87 [0.46], and 0.7 [0.43] pmol/ml, respectively; all P<0.05, Mann-Whitney). A similar trend was found for the distribution of C-peptide levels and to a minor extent the blood glucose values, but these differences failed to achieve statistical significance.Conclusions: Elevated C-peptide and insulin levels potentially represent a pathogenetic factor in the development of cerebral small-vessel disease. However due to insufficient research and relevant resulting data, the hypothesis has yet to be evaluated.