Nodular goiter and its natural selection in modern terms
Vadim Khaziev, Svetlana Shtandel, Yurii Karachentsev & Helena Svetlova-Kovalenko
Aim: The aim of the study was to analyze the nodular goiter (NG) natural selection features in modern terms.
Materials and methods: The average fertility indices per person, 211 patients with NG from the female cohort of Kharkov (eastern Ukraine) inhabitants, years of birth 19251950, mean age 58.6±0.5 years with the physiological cessation of fertility and 2105 normal healthy ones were analyzed. The dead (Pd) and survive (Ps) till reproductive period (25 years) parts of comparison groups offspring, relative adaptability (w) and natural selection (s) were estimated. NG family aggregation at 1st and 2nd degree relatives for 69 patients with multinodular goiters patients and 79 patients with mononodular goiters were studied.
Results: NG women had more offspring by comparison to the healthy ones: number of labors (births) (1.60±0.06 vs 1.41±0.02, correspondingly, P<0.001). The values of Pd and Ps in NG women were different in comparison with the healthy ones (0.002 vs 0.028), (0.980 vs 0.972), accordingly. Natural selection (s) against NG and healthy ones has made 0.000 and 0.126, respectively (P<0.001). NG prevalence in Kharkov population was increased from 0.02% in 1989 to 0.238% in 2007, P<0.001. NG clinical variant of mononodular goiters is characterized by higher familiar accumulation by comparison to multinodular goiter clinical variant (4.36±0.85 vs 1.75±0.58%, respectively; P<0.05). It has been shown, that mononodular goiters prevailed among the total nodal goiters cases and were increased last 24 years (19852009) from 34.1 to 46.2% (χ2=7.817; P=0.005).
Conclusions: In modern terms the positive tendency of NG natural selection is a factor, which increases NG prevalence in population and promotes the increasing of all clinical NG cases with the greater family accumulation.