Relations between interleukin-1, its receptor antagonist gene polymorphism, and bone mineral density in postmenopausal Korean women

Abstract

We investigated the relation between polymorphisms in the interleukin-1(IL-1) and IL-1 receptor antagonist (IL-1ra) gene, and bone mineral density (BMD) in postmenopausal Korean women. The IL-1α C⁻⁸⁸⁹T polymorphism, and IL-1β C⁻⁵¹¹T polymorphism were examined by restriction fragment length polymorphism, and 86-bp variable number tandem repeat polymorphism in the IL-1ra gene was analyzed by the polymerase chain reaction and electrophoresis in 202 postmenopausal Korean women. Serum osteocalcin, and C-telopeptide of type I collagen were measured using a radioimmunoassay and enzyme-linked immunosorbent assay, respectively. BMD at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometer. No significant differences in BMD or in serum bone markers levels were noted across the IL-1α or IL-1β genotype. There were no significant differences in the distribution of IL-1α or IL-1β genotype according to the status of bone mass. BMD in women carrying the A2 allele of the IL-1ra gene was significantly lower than those without this allele, and the A2 allele was more frequent in osteoporotic women than in normal women. These data suggest that IL-1ra gene VNTR polymorphism is a genetic factor that may affect BMD in Korean women.