Metabolic activity of bone tissue osteoblasts in patients with chronic pancreatitis

Abstract

Objective — to investigate the level and role of osteocalcin in patients with chronic pancreatitis, to determine the dependence of changes in this indicator on the vitamin D receptor gene. Materials and methods. Examinations involved 70 patients with chronic pancreatitis (CP), who formed the main group. Women (46 or 66.4%) prevailed in this group. The age of the patients was from 29 to 43 years, the mean age 33.2±2.1 years. Control group consisted of 78 practically healthy subjects. The groups were comparable in terms of age and gender ratio. The diagnostic search included the study of the polymorphism of vitamin D receptor (VDR) gene and the biochemical marker of bone tissue, osteocalcin. Their possible effects on the course of the disease and the formation of complications have been investigated. Results. In the process of determining the VDR gene polymorphism, the significant difference was found in the distribution of gene alleles (χ2=30.08, df=4; p <0.01). According to the results of genetic testing, both groups of patients were divided into three subgroups: 1st subgroup (bb‑genotype carriers), 2nd subgroup (Bb‑genotype carriers), 3rd subgroup (BB‑genotype carriers). In the control group, the distribution was as follows: 27 (38.6%), 34 (48.6%) and 9 (12.8%) patients, in the main group — 13 (18.5%), 30 (42.8%) and 27 (38.7%) patients. With the presence of CP, there was a change in the distribution of alleles towards the BB genotype of the VDR gene, which was associated with a higher risk of osteoporosis. 35 (50.0%) patients with CP and 3 (3.8%) individuals from the control group had a history of bone fractures (p <0.01). In CP, the average osteocalcin level was 22.20±2.53 ng/ml, 27 (38.6%) patients had normal levels, 15 (55.6%) of them had the Bb genotype, 7 (25.9%) — genotype BB, in 5 (18.5%) — genotype bb. A decrease in the level of osteocalcin below the norm (to 12.7±1.87 ng/ml) was registered in 4 (5.7%) patients, of which 2 (50.0%) had the BB genotype, 1 (25.0%) — Bb genotype, another 1 (25.0%) — bb genotype. A higher than normal level of osteocalcin (45.1±23.24 ng/ml) was recorded in 39 (55.7%) patients of the main group, of which 18 (43.6%) had the BB genotype, 14 (35.9%) — Bb genotype, 7 (20.5%) — bb genotype. Conclusions. The course of CP in most cases is accompanied by an increase in osteocalcin levels, which can be considered as an indicator of a violation of the mineral density of bone tissue. Changes in the ratio of genotypes of the VDR gene are registered in patients with CP, which gives reason to assume a violation of the absorption of vitamin D due to genetic aberrations. In the majority of patients with CP, in the presence of an unfavorable genotype (BB) of the VDR gene, an increase in the content of osteocalcin is observed, which can be explained by one of the ways of the formation of osteoporotic conditions — a violation of the differentiation of osteoblasts. Chronic pancreatitis can be considered as an unfavorable nosology that provokes interference in bone metabolism with a high probability of formation of osteoporotic conditions, which requires early diagnosis and prevention of complications.