Introduction:
Glucocorticoids (GCs) are used in the treatment of numerous diseases, and long-term use of GCs causes bone loss. GC receptor activation decreases Bone Mineral Density (BMD) by inhibiting and stimulating osteoblasts and osteoclasts, respectively. GC receptor gene polymorphisms are also associated with increased susceptibility to GCs. The purpose of this study was to assess the relationship between osteoporosis and Glucocorticoid receptor gene (NR3C1) polymorphism in Turkish population.

Material and methods:
The study group consisted of 232 unrelated patients with osteoporosis and 150 unrelated healthy controls. All participants, patients and healthy controls, were of Turkish origin, from the central region of Turkey. Genomic DNA was isolated from whole venous blood samples using a commercial DNA isolation kit. The NR3C1 BclI gene C/G polymorphism was analyzed by polymerase chain reaction.

Results:
The frequencies of CC, CG and GG genotypes in the patients were 34.5%, 48.3%, and 17.2% and in the controls were 48.0%, 42.0%, and 10.0%. A statistically significant difference was observed between patients and controls according to genotype frequencies (p=0.01). C and G allele frequencies of C/G polymorphism were 58.6% and 41.4% in patient group and 69.0% and 31.0% in control group (p=0.005).

Conclusions:
The NR3C1 BclI gene C/G polymorphism could be one of the genetic factors causing osteoporosis.