Structural and functional state of bone in patients with arteriovenous malformations of the lower extremities

Background. Disruption of regional blood flow in patients with arteriovenous malformations (AVMs) of the lower extremities changes the conditions of bone tissue functioning. The purpose was to study the structural and functional state of bone tissue and its metabolism in patients with AVMs of the lower extremities using dual-energy X-ray absorptiometry and the markers of bone turnover. Materials and methods. Fifteen patients with AVMs had been examined. The clinical class of chronic venous disease (CVD) was evaluated according to CEAP; patients were divided into 2 subgroups: the first one was with CVD C1-C3 and the second one was with CVD C4-C6. Bone mineral density (BMD) was studied based on the X-ray absorptiometry. The level of bone metabolism markers, such as procollagen type 1 N-terminal propeptide (P1NP), C-terminal cross-linking telopeptide of type 1 collagen (β-CTx) and osteocalcin, 25-hydroxyvitamin D (25(ОН)D) and parathyroid hormone were studied. Results. Disturbances of the bone tissue indices of the affected limb were found in 70 % of the patients. Also, the statistically significant difference in BMD of the affected limb compared to the healthy limb was established (р = 0.005). A multidirectional level of P1NP was detected; β-CTx exceeded norm in 80 % of the patients; osteocalcin exceeded norm in 33 % of the cases. In 67 % of the patients, a decrease in serum level of 25(OH)D was noted. Increase of the β-CTx level in the first subgroup and its decrease in the second one was associated with stabilization of the AVMs course and age-related changes in the hormonal background of the patients. Conclusions. Disturbances in the structural state of bone tissue of the affected limb were found in 70 % of the patients; statistically significant difference between the BMD of the affected and healthy limb obviously caused by the influence of regional hemodynamic disturbances. Various deviations of the metabolism markers were found, which indicates the need to develop a system of drug therapy.