Age- and menopause-related differences in subcutaneous adipose tissue estrogen receptor mRNA expression.

OBJECTIVES: Changes in estrogen receptor (ER) expression likely underlie differential metabolic effects of estrogen in pre- and postmenopausal women. The aim of the current study was to determine whether ER gene expression in abdominal and femoral subcutaneous adipose tissue (SAT) was associated with age, menopause, or regional adiposity.

METHODS: We studied pre- and post-menopausal (n=23 and 22, respectively; age 35-65y) normal weight (mean±SD; BMI 23.7±2.5kg/m2 ) women with similar total fat mass. Abdominal and femoral SAT ERα (ESR1) and ERβ (ESR2) mRNA expression was determined by qPCR.

RESULTS: Total fat mass did not differ between pre- and postmenopausal women (22.7±5.3vs. 21.7±5.3kg). Compared to premenopausal women, ESR1 and the ratio of ESR1 to ESR2 were lower (p≤0.05) in postmenopausal abdominal and femoral SAT. ESR1 and ESR1:ESR2 were inversely associated with age in abdominal SAT (r=-0.380 and r=-0.463, respectively; p<0.05) and femoral SAT (r=-0.353 and r=-0.472, respectively; p<0.05). ESR2 was not related to age or menopause. The inverse association between ESR1 and age persisted after adjusting for trunk fat mass, estradiol, or leptin.

CONCLUSION: Among healthy pre- and postmenopausal women, increased age was associated with a decreased balance of ERα to ERβ in abdominal and femoral subcutaneous adipose tissue.