Problems of Radiation Medicine and Radiobiology

D. Belyi, G. Pleskach, O. Nastina, G. Sidorenko, N. Kursina, O. Bazyka, O. Kovalev,
A. Chumak, I. Abramenko

State Institution «National Research Center for Radiation Medicine of the National Academy
of Medical Sciences of Ukraine», Melnykov str., 53, Kyiv, 04050, Ukraine

Features of coronary heart disease development in emergency workers of the Chornobyl accident depending on the action of radiation and non-radiation risk factors and genotypes of single nucleotide polymorphism rs966221 of phosphodiesterase 4Dgene

Objective. This study devoted to specific features of coronary heart disease (CHD) development in emergency work- ers (EW) of the accident at the Chernobyl nuclear power plant (ChNPP) based on analysis the interaction between radiation and non-radiation risk factors and single nucleotide polymorphism (SNP) rs966221of phosphodiesterase (PDE)4Dgene.
Methods. It was examined 397 men with CHD, including 274 EW of 1986–1987 and 123 non-irradiated persons (con- trol group) who were 66±10 and 69±11 years old relatively. The program studies included clinical examination, elec- trocardiography (ECG), ECG daily monitoring, ECG stress testing, echo-doppler-cardiography, analysis of serum lipid spectrum, polymerase chain reaction with restriction of reaction products, retrospective analysis of case histories. Diagnosis of CHD or its approval was carried out in accordance with the standards of diagnosis, accepted in Ukraine. All EW before their taking part in cleaning ChNPP territory did not suffered from CHD.
Results. According to the analysis of contingency tables, carriers of the TT genotype of rs966221increased the risk of myocardial infarction (MI) in 2.538 times compared with carriers of genotypes CC and CT. The use of Kaplan-Meier method showed that a half of EW with the TT genotype developed MI before 64 years old, while with the other geno- types up to 78.7 years old. In the control group statistically significant increase of cumulative proportion of patients with MI, carriers of the TT genotype, began from 60 years old. Compared to the non-irradiated patients EW fell ill with CHD on 9.4 years earlier. Using proportional hazards analysis (Cox regression), it was found that EW had
3.9 times higher risk of CHD than in non-irradiated individuals. Smoking and overweight brought three times less but significant risk – 1.37 and 1.33 respectively. The TT genotype unlike genotypes CC and CT gene PDE4D increased risk of MI in 1.757 times more both in EW and control group.
Conclusions. The risk of CHD development was determined by radiation factor, such as the involvement in the emer- gency works of the accident consequences, as well as non-radiation factors, namely smoking and overweight. Only one factor, the TT genotype of rs966221 PDE4Dgene, determined the risk of MI occurrence in EW and non-irradiated controls. In the post-emergency period, CHD developed 6 years earlier in EW with the TT genotype than in patients with genotypes CC and CT.
Key words: emergency workers of the accident at the Chernobyl nuclear power plant, ionizing radiation, coronary heart disease, myocardial infarction, SNP rs966221of phosphodiesterase 4Dgene.

Problems of radiation medicine and radiobiology. 2016;21:204–217.