Collagen type Ialpha1 gene polymorphism in idiopathic osteoporosis in men.

OBJECTIVE To analyse the distribution of polymorphism of the collagen type Ialpha1 gene (COL1A1) and its relationship with bone metabolism and bone turnover in men with idiopathic osteoporosis. METHODS A total of 35 male patients with idiopathic osteoporosis, aged 50.4 +/- 10.3 yr, and 60 healthy males (controls), aged 47 +/- 17 yr, were included in the study. Serum osteocalcin, 25-hydroxyvitamin D and parathyroid hormone were determined in all patients. The COL1A1 Sp1 genotypes (SS, SS:, ss) were assessed by restriction enzyme digestion (BAL:1) of DNA amplified by the polymerase chain reaction. RESULTS Patients with idiopathic osteoporosis had a higher frequency of the s allele than men in the control group (29 vs 11%, P: = 0.003) and a higher frequency of the SS: genotype (patients, 48% SS, 46% SS:, 6% ss; controls, 80% SS, 18% SS:, 2% ss; P: = 0.003). No significant differences between genotypes were observed in serum concentrations of osteocalcin, vitamin D or parathyroid hormone among either the patients or the controls. CONCLUSION This study suggests that, in men with idiopathic osteoporosis, there is a high prevalence of the s allele and the SS: genotype that is unrelated to other parameters of bone metabolism.