Collagen type I alpha 1 gene polymorphism in idiopathic osteoporosis in men

Objective. To analyse the distribution of polymorphism of the collagen type I alpha1 gene (COLIAI) 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 inc luded in the study. Serum osteocalcin, 25-hydroxyvitamin D and parathyroid hormone were determined in all patients. The COL1A1 Spl genotypes (SS, Ss, ss) were assessed by restriction enzyme digestion (Ball) of DNA amplified b y the polymerase chain reaction. Results. Patients with idiopathic osteoporosis had a higher frequency of th e s allele than men in the control group (29 vs 11%, P = 0.003) and a highe r 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 genot ypes were observed in serum concentrations of osteocalcin, vitamin D or par athyroid 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 unre lated to other parameters of bone metabolism.