Prevalence of low bone mass and vitamin D deficiency in pediatric and adult patients with cystic fibrosis in Republic of Macedonia.

UNLABELLED Bone disease in cystic fibrosis (CF) has become a topic of widespread interest and impact in the CF community. Recently, some biochemical markers have been proposed to provide information about the dynamics of bone turnover. Only limited information is available for young patients. Imbalance between bone formation and degradation in CF especially in puberty has become an important issue for developing osteopenia. Influence of vitamin D receptor alleles on BMD suggests that these polymorphisms have a greater influence on BMD in childhood. The aim of our study was to assess prevalence of vitamin D deficiency and osteopenia in pediatric and adult CF patients. METHODS The study included 77 clinically stable CF patients (range 5-36 y), who regularly attended CF center at the Pediatric Clinic in Skopje, Macedonia. Serum osteocalcin (OC), βcrosslaps, 25OHD and PTH were determined by electrohemiluminiscent method. BMD was measured via dual energy-ray absorptiometry (DXA) scans with spinal scores recorded. RESULTS 50% of the CF patients with PI had serum vitamin D>20 ng (range 10-44 ng/ml) with no difference of age. Osteopenia was determined in 35% of patients. High plasma βcrosslaps values reflect raised osteoclast activity in 50% of patients with osteopenia. We found one CF patient homozygote for Taq1 and Bsm1, one for Taq1 and one for Fok1. These patients have vitamin D deficiency and osteopenia. CONCLUSIONS Bone remodeling in CF patients is impaired. Further investigations are needed to find underlying pathogenesis of low bone mass and vitamin D deficiency.