Endocrine Abstracts

Introduction: Accident at the Chernobyl NPP (ChNPP) in Ukraine on the 26th of April, 1986 was followed by the intensive release of a wide range of radioactive elements with affinity to many endocrine tissues. The mentioned radioactive fallout resulted in both internal and external radiation exposure, among others, of the central endocrine structures of the human brain.

Methods: We have conducted a retrospective analysis (20–25 years upon radiation exposure) of anthropometric indices in 606 survivors of the ChNPP accident and in 589 not exposed persons from the general population of Ukraine (i.e. control group). Basal serum levels of α-melanocyte-stimulating hormone (α-MSH), leptin and some other hormones were assayed in 100 of study subjects.

Results: Higher incidence of borderline obesity – 37% (χ²_Yates=4.22, P=0.04) and of primary obesity – 32.5% (χ²_Yates=8.5, P=0.004) was found in the ChNPP accident survivors vs persons in the control group (31.1 and 24.6% respectively). Normal body mass was more prevalent in the general population (39.3%; P=0.002). The subgroup analysis indicated that primary obesity was more often found in ChNPP accident emergency workers of the so-called ‘non-iodine period’ of 1986–1987 (47.3%) and of ‘iodine period’ of 1986 (34.2%). For the first time there was revealed a new abnormal way of a reaction on radiation namely – the ‘blunted’ protective response of the physiological increase of α-MSH secretion along with body mass index elevation normally preventing further growth of adipose tissue. There is no increase of α-MSH secretion or even there is a hormone deficiency in most survivors of the ChNPP accident having borderline obesity or obesity.

Conclusions: Received data indicate to the increased risk of borderline obesity and obesity after the prolonged exposure to radiation in moderate doses. The mentioned risk is stipulated by disorders in melanocortin system resulting in α-MSH deficiency at the background of obesity that can be considered as a marker of such an abnormality.