Bone mineral density of the lumbar spine is associated with TNF gene polymorphisms in early postmenopausal Japanese women.
We investigated the relationships between tumor necrosis factor (TNF) gene polymorphism, circulating TNF-alpha (TNF-alpha) concentrations, and bone mineral density (BMD) in the lumbar spine. TNF gene polymorphisms studied were the Nco I polymorphism within the first intron of TNF-beta (TNF-beta) and three single nucleotide polymorphisms in the promoter region of the TNF-alpha gene, at positions -857, -863, and -1031. Allelic variants of the TNF gene were identified using restriction fragment length polymorphism (RFLP) analysis in 177 postmenopausal Japanese women within 10 years after menopause, aged 56.4 +/- 4.5 years (mean +/- SD). A significantly higher prevalence of the alleles TNF-alpha-863A (20.3% versus 9.9%) and TNF-alpha-1031C (21.3% versus 12.4%) was seen in the low BMD group (Z-score < 0, n = 91) than in the high BMD group (0 < Z-score, n = 86). In genotype analysis, although difference did not reach a significant level, women with the rarest allelic variants, i.e., homozygous TNFbl, TNF-alpha-863A, and TNF-alpha-1031C, showed the lowest BMD Z-scores. Women with another rarest allelic variant, TNF-alpha-857T/T had significantly lower BMD Z-scores than did women with TNF-alpha-857C/T or -857C/C. The BMD Z-score decreased significantly with an increase in the total number of such rare alleles. Serum concentrations of TNF-alpha did not differ significantly among groups divided by genotypes. Multiple linear regression analysis revealed that the total number of rare alleles, in addition to the body mass index and the number of years since menopause, was an independent predictor of the BMD. These presumptive functional polymorphisms of the TNF gene may be associated with the lumbar spine BMD in early postmenopausal Japanese women.
Furuta
I
I
Department of Obstetrics and Reproductive Medicine, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan. furuchan@med.hoku-dai.ac.jp
Kobayashi
N
N
Fujino
T
T
Kobamatsu
Y
Y
Shirogane
T
T
Yaegashi
M
M
Sakuragi
N
N
Cho
K
K
Yamada
H
H
Okuyama
K
K
Minakami
H
H
D015502:Absorptiometry, Photon; D044466:Asian People; D015519:Bone Density / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D015810:Linkage Disequilibrium; D008159:Lumbar Vertebrae / Q000378:metabolism*; D008233:Lymphotoxin-alpha / Q000235:genetics; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha