Background and objectives: Osteoporosis is a common disease of the elderly, in which genetic and clinical factors contribute to the disease phenotype. Since the production of interleukin-1 (IL-1) has been implicated in the bone mass and skeletal disorders, we investigated whether IL-1 system gene polymorphisms are associated with the pathogenesis of osteoporosis in postmenopausal Taiwanese women.
Methods: Osteoporosis is diagnosed by dual-energy x-ray absorptiometry, which measures bone mineral density (BMD) at multiple skeletal sites. We studied the IL-1α (-889C/T), IL-1β (-511C/T) and the 86 base pair variable number tandem repeat (VNTR) in intron 2 of the IL-1 receptor antagonist (IL-1ra) gene in 117 postmenopausal women with osteoporosis and 135 control subjects without a history of symptomatic osteoporosis. These gene polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymerase. Blood sugar and other risk factors were also determined.
Results: The frequencies of IL-1β (-511C/T) genotypes (P=.022, odds ratio=1.972) and alleles (P=.02, odds ratio=2.909) showed a statistically significant difference between the two groups. However, we did not find any statistically significant difference in IL-1β and IL-1ra polymorphisms (P>.05). We also observed a positive relationship between osteoporosis and cholesterol and a weak inverse relationship between blood sugar and osteoporosis in postmenopausal women.
Conclusions: These experimental results suggest that the pathogenesis of osteoporosis is associated with IL-1β (-511C/T) polymorphism in postmenopausal women. This polymorphism is an independent risk factor for osteoporosis.