The Prevalence of Δ508 in Cystic Fibrosis Patients with Low Bone Mineral Density in Republic of Macedonia

Introduction : Reduced bone mass density (BMD) is frequent in patients with cystic fibrosis (CF). Pathogenesis of CF bone disease is multifactorial. Many studies suggest that there is genetic component, independent of the disease severity and nutritional deficits. Aim: To determine the prevalence and identify determinants of reduced BMD in CF patients. Material and methods: The study included 80 CF patients (range 5-36y.). BMD was measured via dual-energy x-ray absorptiometry (DXA) scan. Vitamin D level was assessed by plasma 25OHD levels (<15ng/ml)was defined as deficiency. Results: 42 CF patients were homozygote for ΔF508mutationand 26.2% have lower BMD (-0.43 ±0.99SD), five with osteoporosis. 25OHD was <15ng/ml in 21.4%, homozygote CF patients. In group with heterozygote for ΔF508(28 CF patients) low BMD have 32.1% (-0.53±1.13SD), two with osteoporosis. Severe deficiency of 25OHD< 15ng/ml in heterozygous group have 39.2 %. Ten CF patients have other mutations, 50% have low BMD (0.45±1.2SD), one have osteoporosis. There was one patient with severe deficiency of 25OHD (10%). Conclusion:ΔF508 genotype was associated with impaired bone turnover (decreased osteoblast activity). Reduced bone mineral density in cystic fibrosis is associated with a number of factors including ΔF508 genotype, deficiency of vitamin D, lung disease severity and malnutrition.