Objective To investigate the association of CA repeat polymorphism and G1082A polymorphism of the estrogen receptor β (ESR2) gene with bone mineral density (BMD) in postmenopausal women.   Methods Two hundred postmenopausal women who visited our outpatient clinic were enrolled. The CA repeat polymorphism of ESR2 gene was determined by gene scan and DNA sequence methods. The G1082A polymorphism of ESR2 gene was detected by

polymerase chain reactionrestriction fragment length polymorphism. BMD for the proximal femur and lumbar spine (L

2

-L

4

) was measured by dual-energy X-ray absorptiometry.   Results The  (CA)

n

22 and (CA)

n

≥22 alleles were designated as S and L

respectively. The frequency of genotypes in 200 postmenopausal women was as follows: SS (25.0%)

SL (46.0%)

LL (29.0%) for CA repeat polymorphism

and rr (43.0%)

Rr (42.0%)

RR (15.0%) for G1082A polymorphism. The distribution of genotypes was in Hardy-Weinberg equilibrium. After adjusting for age

menopausal period

height

weight and body mass index

BMD was higher in postmenopausal women with SS genotype than SL or LL genotype for CA repeat polymorphism at femoral neck (P0.01)

but there was no significant difference in BMD of trochanter

Wards triangle and lumbar spine for different genotypes (P0.05). In different genotypes for G1082A polymorphism

there was no significant difference in BMD of each skeletal region (P0.05). The ESR2 polymorphism was not in linkage disequilibrium (P0.05).  Conclusion In postmenopausal women

CA repeat polymorphism in the fifth intron of the ESR2 gene may contribute to the genetic regulation of BMD

but the G1082A polymorphism in the fifth exon of the ESR2 gene may not significantly affect BMD.