Association of osteoarthritis and bone mineral density in women - The health and nutritional examination survey in Kuri

Abstract

Previous studies, reporting the inverse relationship between osteoarthritis and osteoporosis suggest the existence of possible pathophysiologic mechanisms between them. To examine the hypothessis that "bone mineral densities of women with osteoarthritis are significantly higher than that of women without osteoarthritis in Korea", subjects from the health and nutritional examination survey in Kuri city were sampled.

Samples were selected through multi-stage sampling frame using established clusters in Kuri city. From August 18 to September 10, 1997, the survey was conducted. Among the total number of selected sample population(1,656 people), response rate was 52.4 percent(348 men and 519 women). 420 women who took BMD measurement, radiologic exam, and anthropometric exam were selected for the analysis. The analysis results are as follows.

1. General characteristics : Mean BMD was 0.493 g/㎠, mean age was 43.0, mean BMI was 23.9 ㎏/㎡. The number of women who experienced menopause was 106, hysterectomy was 19. There were 0 case of osteoarthritis of hip, 64 cases of osteoarthritis of knee, and 2 cases of osteoarthritis of hand.

2. Univariate analysis results : Mean BMD of women with the osteoarthritis of knee was significantly lower than that of women without the osteoarthritis of knee(0.4296 vs. 0.5057 g/㎠). But, there were to few cases of osteoarthritis of hip and hand, so comparative studies of BMD in ostearthritis of hip and hand could not be conducted. There were significant differences of BMD among pre-menopause group(0.5204), post-menopause group(0.4206), and hysterectomy group(0.4881). Additionally, there were significant differences of BMD among diabetes group(0.4297), impaired glucose tolerance group(0.4874), and normal group(0.5057). Furthermore, age, parity, BMI, bioimpedance wer significantly related with BMD.

3. Multivariate analysis results : To examine the relationship between osteoarthritis and BMD while controlling the other variables' effects which were significant in the univariate analyses, multiple linear regression analysis was done. But, it was found that osteoarthritis of knee was not a significant variable to BMD anymore. While age and menopause had significant negative relationship with BMD. Diabetes, parity, BMI, and bioimpedance did not have significant relationships with BMD. After stratification of subjects according to menopause, multiple linear regression analyses were done to each strata. Consequently, age in post-menopause group, age and osteoarthritis of knee in hysterectomy group showed significant negative relationship with BMD.

The results did not support the many results of other previous studies done with white men and women. Further studies of biological plausibility to Korean women are recommended. Also it is suggested that longitudinal study to verify the relationship between osteoarthritis and BMD will be valuable.