Endocrine Abstracts

Endocrine comorbidity is a hot issue in radiation medicine featuring a concomitant radiation injury of several endocrine glands.

Objective: Establishing a link of vitamin D deficiency with thyroid and pancreatic disorders among the Chornobyl nuclear power plant (ChNPP) accident survivors.

Results: A blind sample (n = 60) of subjects treated at the Radiation Endocrinology department in 2019 were selected for the study. Study sample included the ChNPP accident survivors (group 1, n = 40) with 20 females (50%) and 20 males (50%) among them. The comparison group included patients (group 2, n = 20) not exposed to radiation with 11 females (55%) and 9 males (45%) among them. Age of study subjects ranged from 37 to 75 years old (60.2 ± 9.8 years at an average). Failure of compensation of type 2 diabetes was the most common reason for hospital admission (48.3%), failure of compensation of hypothyroidism was in second place (46.7%). Incidence of the increased risk of vitamin D deficiency and excessive parathyroid hormone production in the Chernobyl accident survivors was somewhat higher than in non-exposed individuals, however with no significant difference (respectively 81.08% and 78.12%; χ² = 0.257, P = 0.612; 31.12% and 28.08%; χ² = 0.462, P = 0.319). Using a multivariate analysis the reliable model was obtained confirming the relationship of increased parathyroid hormone level and early subclinical signs of the target organs damage (F = 4.294; P = 0.042), which proves the feasibility of clinical questionnaires application. Reliable positive relationship was found between the vitamin D and free thyroxine levels (r = 0.729; P = 0.001) and negative one was found with the thyroid-stimulating hormone content (r = −0.803; P = 0.001) in the ChNPP accident survivors, indicating a direct impact of vitamin D deficiency on the course of hypothyroidism. Decreased vitamin D concentration in the ChNPP accident survivors having got type 2 diabetes correlated with increased duration of metformin medication (r = −0.421; p = 0.001) and body mass index (r = −0.787; P = 0.001) indicating the need for correction of such insufficiency in the given contingent of patients. It was found that the parathyroid hormone level increases along with the duration of type 2 diabetes and increase in creatinine clearance (r = 0.724; P = 0.001 and r = 0.799; P = 0.001).

Conclusions: Vitamin D deficiency has a negative effect on the course of comorbid disorders (type 2 diabetes and hypothyroidism) and excessive production of parathyroid hormone.