Objective    To investigate the correlation of a G/A at Val80 in the third exon and a TTTA repeat polymorphism in the forth intron of cytochrome P450 family 19 (CYP19) gene with postmenopausal osteop

orosis (PMO) in Chinese Han population.     Methods    A case-control study was carried out on 78 femoral neck PMO patients and 122 matched controls

and 108 lumbar spine (L

2-4

) PMO patients and 92 controls. Inclusion criteria

at the age of 41 to 65

Han nationality

living in Chongqing more than 10 years

with natural menopause over 1 year

no history of taking drugs affecting bone metabolism. Exclusion criteria: menopause too early (younger than 40 years old)

secondary osteoporosis or disease affecting bone mineral density

or consanguinity. Genotypes for the Val80 polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotypes for the (TTTA)n polymorphism were determined by gene scan and DNA sequencing. The (TTTA)n ＜10 and (TTTA)n ≥10 alleles were designated S and L

respectively. Bone mineral density for the proximal femur and L

2-4

was measured by NORLAND XR-46 dual-energy X-ray absorptiometry (DEXA).     Results    The genotype distribution in each group was met with Hardy-Weinberg equilibrium at each skeletal site (P0.05). There was no significant difference in the genotype and allele distributions of Val80 polymorphism between PMO group and control group at the femoral neck and L

2-4

sites (P0.05). At the femoral neck site

there was no significant difference in the genotype and allele distributions of (TTTA)n polymorphism between PMO group and control group (P0.05). But the SS genotype and the S allele frequencies of PMO group were significantly higher than those of control group at the L

2-4

(P0.05). After adjustments for age

years after menopause

menopausal age

and body mass index

Logistic regression analyses revealed only the (TTTA)n polymorphism remained significantly associated with PMO at the L

2-4

(P0.05). The subjects with the combined SS and SL genotype had higher risk of PMO compared with those with the LL genotype (adjusted OR=2.246

95% CI 1.070 to 4.715

P=0.032).     Conclusion 

   CYP19 (TTTA)n polymorphism is independently correlated with PMO at the L

2-4

in Chongqing Chinese Han population. The presence of the S allele T may dominantly increase the risk of PMO at the L

2-4

. The data also suggest that the CYP19 Val80 polymorphism might not be associated with PMO.