New atherosclerosis progression markers in patients with post-Chernobyl metabolic syndrome

Abstract

Relevance. As an epidemiologically proven consequence of the Chernobyl NPP accident, circulatory diseases are among the leading morbidities in liquidators. To predict the development of adverse cardiovascular events in patients with metabolic syndrome, there is the ongoing search for informative laboratory markers.The objective is to show how osteopontin, osteoprotegerin, fetuin-A, and risk factors for genetic circulatory disorders are associated with traditional risk factors for circulatory disorders in Chernobyl nuclear power plant accident liquidators suffering metabolic syndrome. Another objective is to explore the perspectives to use these indicators to forecast coronary atherosclerosis progression.Methods. The study group included 50 male liquidators of the Chernobyl nuclear power plant accident who suffered metabolic syndrome. The patients were split in two groups depending on osteopontin concentration in blood serum, i.e. above or under the upper reference limit. Medical history data, biochemical parameters, including inflammatory proteins, osteoprotegerin, fetuin-A, and genotyping of polymorphic variants of genes associated with the risk of circulatory diseases were analyzed. A control group of 30 conditionally healthy men was formed to determine the normal osteopontin, osteoprotegerin and fetuin-A values in blood serum.Results and discussion. With osteopontin value exceeding 21.4 ng/mL, the liquidators’ medical history showed 1.5 times higher frequency of myocardial infarction, 2.5 times higher frequent history of acute cerebral circulation disorder; ischemic heart disease was associated with type 2 diabetes mellitus. It was shown that the group of liquidators (osteopontin over 21.4 ng/ml) was characterized by a reliable increase in atherogenicity coefficient and osteoprotegerin level. Meanwhile, when compared to the control group, the same group of patients showed lower fetuin-A values and elevated high-sensitivity C-reactive protein, homocysteine, leptin and ghrelin. It was found that in liquidators, the presence of the A allele in the vitamin B12-dependent methionine synthase (MTR) gene (2756 A>G) is associated with more pronounced biochemical markers of atherosclerosis progression compared to GG genotype carriers.Conclusion. Osteopontin performs a protective role in tissue damage, being is practically undetectable in normal conditions. However, in case of pathology its value increases dramatically. In patients with metabolic syndrome, decreased fetuin-A and osteopontin values exceeding 21.4 ng/mL require additional examination with a focus on cardiovascular pathology (coronary artery calcinosis), as well as a dual-energy X-ray absorptiometry to ensure early detection of diminished bone mineral density and body mass. It was found that in liquidators, the presence of A-allele (genotypes AA and AG) in the MTR 2756 A>G gene is characterized by deeper atherogenic changes in the lipid spectrum, increased atherogenicity coefficient and decreased adiponectin content. This justifies the need for genotyping to build individual forecast for atherosclerosis progression in this category of patients.