[The influence of the vitamin D3 level in the blood serum of lactase gene polymorphism on the development of chronic polypous rhinosinusitis].

The objective of the present study was to elucidate the possible correlations between the vitamin D level in the blood serum and lactase gene polymorphism (LCT-13910 T>C) in the patients presenting with chronic polypous rhinosinusitis (CPRS). The study included 50 patients with this condition and 14 subjects comprising the control group. The variants of lactase gene polymorphism (LCT-13910 T>C) were identified with the use of polymerase chain reaction (PCR) in real time. The total level of serum vitamin D (VD) was determined by means of the immunochemical analysis (the electrochemiluminescence technique). In the group of patients presenting with chronic polypous rhinosinusitis, the level of VD in the blood serum ranged from 48 nm/l to 85 nm/l (mean 60 nm/l) compared with that in the patients of the control group (from 78 nm/l to 112 nm/l; mean 97 nm/l) . The level of vitamin D 'below the normal values' was documented in 71% of the patients with CPRS in comparison with 7% in the control subjects. Lactase gene polymorphism (LCT-13910 CC, CT) suggesting pronounced and latent hypolactasia was identified in 94% of the patients with CPRS compared with 78.6% in the control group. The occurrence of the CC genotype in the patients of both study groups was virtually identical: 52% in the patients presenting with chronic polypous rhinosinusitis and 57% in the control group. CT polymorphism was identified in 42% of the patients with CPRS and in 21% of the control subjects. The significant difference between the patients of the two groups was documented for the occurrence of TT polymorphism: 6% among the patients with CPRS and 21% in the controls (i.e. much higher in the healthy subjects). There was no significant difference between the serum levels of vitamin D either among the patients with CPRS having LCT-13910 gene polymorphisms (CC, CT, TT) or among the control subjects. It is concluded that the study revealed the higher levels of vitamin D in the blood sera from the control subjects in comparison with that in the patients with chronic polypous rhinosinusitis. Moreover, the patients of the latter group more frequently exhibited the variant of the LCT CT-13910 gene polymorphism suggesting latent hypolactasia whereas the subjects comprising the control group more frequently had the variant of the LCT CT-13910 gene polymorphism indicative of the normal tolerance of lactose.