Estrogen receptor α and β gene polymorphism in relation to bone mineral density and lipid profile in Northeast Indian women

Estrogen regulates bone homeostasis and has a cardio-protective effect. Its physiological functions are mediated through receptors (ER) whose expression can be regulated by presence or absence of polymorphisms. However, the association between ER polymorphisms and BMD as well as lipids are inconsistent. The aim of the study was to investigate whether polymorphisms in ESR are associated with bone mineral density (BMD) and lipids in a cohort of Indian women. We studied Pvull, Xbal polymorphisms in ESR1 and AM, Rsnl polymorphisms in ESR2 genes and their association with bone mineral density (BMD) and lipids in premenopausal (n = 293, mean age: 33.01 +/- 5.23 years) and postmenopausal (n = 145, mean age: 56.91 +/- 7.1 years) women from Northeast India. AluI and RsaI polymorphisms in ESR2 gene were associated with BMD in postmenopausal women. Logistic regression analysis adjusted for age, BMI, tobacco and alcohol consumption revealed that xx genotype in Xbal polymorphism is associated with osteopenia at spine (OR = 3.3, 95% CI = 1.067-10.204) in postmenopausal women suggesting that allele X is protective (OR = 0.419, 95% CI = 0.177-0.991). Genotype as in AluI polymorphism, seemed to be protective (OR = 0.092 for osteopenia; OR = 0.152 for osteoporosis) at spine whereas A allele was associated with osteopenia at femur (OR = 2.123, 95% CI = 1.079-4.166) in postmenopausal women. Allele r of RsaI polymorphism, was associated with osteoporosis at spine (OR = 3.222, 95% CI = 1.302-7.96). Thus, AluI polymorphism of ESR2 gene was associated with spinal and femoral BMD whereas RsaI only with spinal BMD in postmenopausal women and ESR genotypes were not associated with lipids.