Endocrine Abstracts

More that three decades have passed since the Chernobyl nuclear power plant accident (ChNPPA). Several million survivors of the accident were exposed to radioactive iodine and mixture of other radioactive isotopes. Endocrine glands occurred among the target organs of radiation exposure in survivors. Insulin resistance and metabolic syndrome (MS) are among the ChNPPA health consequences.

Objective: Evaluation of the role of abnormal thyroid function in presentation of MS key components among the ChNPPA survivors three decades upon.

Results: Clinical examination was carried out in the 265 persons (143 males and 122 females) born in 1956–1968 (49–61 years old now) having thyroid disease with concomitant MS. Study group included the ChNPPA clean-up workers (n=119), residents of radiologically contaminated territories (n=102), and a control subgroup (n=44). Nodular goiter was the predominant disease in survivors with an incidence (26.7±5.7%) three-fold exceeding a respective value in the control subgroup (8.1±2.2%) (P<0.05). Subclinical hypothyroidism was also tree-fold more frequently revealed in survivors vs. in the control subgroup (35.4±6.3% and 12.5±39% respectively, P<0.05). A direct correlation between the thyroid-stimulating hormone (TSH) level and MS main components, namely the systolic and diastolic blood pressure, levels of total cholesterol and triglycerides, body mass index was found in the ChNPPA survivors in a late post-accidental period (r=0.851, P=0.001; r=0.764, P=0.001; r=0.819, P=0.001; r=0.854, P=0.001; r=0.823, P=0.001 respectively). Inverse correlation was revealed between the free thyroxin level and above mentioned MS components (r=−0.605, P=0.001; r=−0.572, P=0.001; r=−0.521, P=0.001; r=−0.497, P=0.001; r=−0.541, P=0.001 respectively). When using the FINDRISK scale a correlation was found between the TSH increase and risk of diabetes mellitus (F=3.75, P=0.015), which coincides with the Rotterdam study data. The cardiovascular risk scores according to the SCORE scale are also worse in patients having a subclinical hypothyroidism (F=3.43, P=0.038).

Conclusions: Subclinical hypothyroidism both with low normal thyroxin level state lead to worsening of all the MS components, namely, affect the clinical course of arterial hypertension, dyslipidemia and abdominal obesity, worsen cardiovascular risks and risk of diabetes mellitus, requiring timely correction of thyroid dysfunction.