OBJECTIVE: To examine whether polymorphisms of the estrogen receptor (ER) α gene are associated with body fat distribution.

DESIGN: Cross-sectional, epidemiological study of two single-nucleotide polymorphisms, a T→ C (PvuII) and an A→ G (XbaI), in the first intron of the ERα gene.

SUBJECTS: A total of 2238 community-dwelling middle-aged and elderly Japanese population (age: 40–79 y).

MEASUREMENTS: The ERα genotypes (by automated fluorescent allele-specific DNA primer assay system), anthropometric variables, fat mass (FM) and percentage FM (% FM)(by dual-energy X-ray absorptiometry).

RESULTS: FM and waist were inversely associated with age (r=− 0.630 and− 0.504, respectively) in women with the GG genotype. On the other hand, waist circumference of the AA genotype was positively correlated with age (r= 0.231). Thus, for middle-aged women (40–59 y) with the AG or GG genotype body mass index (BMI),% FM, FM, waist, hip and waist-to-hip ratio (WHR) were larger than those with the AA genotype. In particular, FM and waist were greater by 20% and 9%, respectively, for the GG genotype, compared to the AA genotype. Alternatively, FM and waist were smaller by 18% and 6%, respectively, in older women with the GG genotype, compared to the AA genotype. No effect was found among the A→ G polymorphisms for men. For both genders, no difference was found in any variables among the TT, TC and CC genotypes with the exception of BMI of older men (60–79 y).

CONCLUSION: No association was found between the ERα gene polymorphisms and body fat distribution in men. For women, the A→ G polymorphism, in particular the GG genotype, may contribute to the development of upper-body obesity in middle-aged individuals, but may serve to decrease the whole-body and abdominal fat tissue of older individuals.