[Genetic polymorphism of the calcitonin receptor gene and bone mineral density in Polish population of postmenopausal women]

Abstract

Introduction: In recent years the influence of genetic factors in the pathogenesis of osteopenia and osteoporosis was indicated. The investigations focused on the gene coding for calcitonin receptor. The goal of our analysis was to determine the genotype frequencies of AluI polymorphism of the calcitonin receptor gene (CTR) in the group of Polish postmenopausal women and its possible contribution to osteoporosis development.

Material and methods: 139 postmenopausal women with osteopenia (t-score value from -1.0 to -2.5) (mean age 58.5 +/- 5.9 years, mean age of menopause 49.8 +/- 3.9 years) have been investigated. AluI polymorphism of the CTR gene was determined using PCR/RFLP assay. We have analysed 3 subgroups: CC, CT, and TT. In each subgroup mean weight, height, body mass index (BMI), mean age of menopause and years since menopause (YSM) and parameters of bone turnover: bone mineral density (BMD), t-score, index: young adults (YA) and--age matched (AM) have been analysed. Additionally the group of 138 selected women (mean age 26.5 +/- 4.3 years) as general population has been analysed.

Results: In investigated group the frequency of all 3 genotypes was determined as follows: CC: CT : TT = 8.6 : 45.3 : 46.1. Analysing BMD in particular subgroups the higher value for the CT genotype (0.967 +/- 0.161 g/cm2) was found. Similarly t-score (-1.94), YA (80.6%) and AM (90.8%) index were higher in CT genotype carriers.

Conclusion: Our results suggest possible connection of the AluI polymorphism of the CTR gene with osteopenia and osteoporosis development. To confirm this tendency further investigations in the large number population are necessary.