| Abstract | | Twenty-four late postmenopausal women with osteoporosis were studied. According to Bsm I polymorphism of VDR gene, the patients were separated in three subgroups: BB (n= 8), Bb (n =10) and bb (n = 6). They did not differ in age (mean ages were 66.0 years, 65.9 years and 63.9 years respectively) nor in years after menopause ( 18.7 years,18.1 years and 18.4 years) or in body weight (64.9 kg, 65.3 kg and 63.8 kg), the variables known to be associated with BMD. The results show the response to the antiresorptive bisphosphonate therapy in combination with calcium supplementation is modified by VDR genotype. The lumbar spine BMD increased significantly faster in BB and Bb (7.3 % and 7.0 %, respectively) compared to bb (2.5 %) during the one- year cyclic ethidronate therapy (400 mg/day) and Ca supplementation (1000 mg/day). The biochemical marker of bone resorption (hydroxyproline urine excretions) as well as the bone formation marker (serum levels of osteocalcin) were decreased during the treatment. In regard to VDR genotype a significantly higher decrease in osteocalcin in bb as compared to BB was observed. We can conclude the VDR genotype is involved in individual's response to the cyclic etidronate with Ca supplementation therapy.
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