Vitamin D receptor gene polymorphism affects bone mineral density: An analysis by fuzzy mathematics
To find defects in genes that cause diseases, geneticists test whether a change or variation in a gene is associated with a disease or an increased susceptibility. Morrison first reported in 1994 that a slight variation in the vitamin D receptor gene (VDRGP) is associated with a significant change in our bone mineral density (BMD). By January of 1997, seventy-five independent investigations had been published, and no consensus had been reached as to whether BMD is really associated with VDRGP. We analyzed all the 75 publications using a fuzzy mathematics approach to address this issue. We use two methods, one based on preference relations, and the other based on p-values. Fifty-five studies on spinal BMD and 73 on hip BMD were analyzed. Results,from method I found that VDRGP affects spinal BMD strongly among pre-menopausal populations, and moderately among post-menopausal populations, and populations with pre- and post-menopausal women combined. No relations were found in populations with males and females combined. VDRGP was associated with hip BMD among pre-menopausal, but not any other, populations. Using method II we found that VDRGP was associated with spinal BMD only in pre-menopausal women, and VDRGP was somewhat associated with hip BMD in ail four types of populations. Conclusion: BMD is associated with VDRGP in certain populations, but not in others. Heterogeneity of populations studied seems to be responsible for the discrepancies among studies. (C) 1999 Elsevier Science Inc. All rights reserved.
vitamine d receptor gene polymorphism bone mineral density fuzzy mathematics group decision analysis