The Effects of BMI and Genetic Variation of Adipokines on Serum Concentrations of Hormones in Untreated Individuals with Breast Cancer; a Pilot Study

Background: Numerous studies have shown an association between hormones secreted by adipose tissues and cancer development. Objectives: This study aimed at investigating the effect of body mass index (BMI) and genetic variation of leptin and adiponectin on serum concentrations of leptin, adiponectin, and estradiol among untreated breast cancer. Methods: This case-control study was performed on 350 women (175 women with breast cancer and 175 healthy controls), who had not taken any medications. Serum levels of estradiol (17-beta estradiol), leptin, and adiponectin were measured, using the ELISA technique. Single-nucleotide polymorphisms of leptin gene (LepG2548A), leptin receptor (Q223, K109R, and K656N), and adiponectin gene (T45G, G276T, C11377G, and 11391A) in blood-isolated DNA were evaluated, using RFLP-PCR technique. Results: Body mass index can affect serum concentrations of hormones and is associated with breast cancer. Also, except for adiponectin C11377G polymorphism, other all genetic variations showed significant relationships with breast cancer. In both groups, BMI was significantly correlated with the mean serum concentrations of hormones, and the risk of breast cancer increased in G2548A, Q223R, K656N, and G276T polymorphisms. The effect of risk allele genotypes on serum concentration of hormones showed that changes in serum concentration of estrogen and leptin in all studied polymorphisms were associated with breast cancer in postmenopausal women. But adiponectin level was only affected by polymorphisms K109R, K656N, and G276 and G11391A. Conclusions: High BMI and genetic variation can affect cancer development by changing the serum concentrations of hormones in different genotypes. Studying various populations’ genetics and lifestyle can help definitive conclusions about genetics and obesity.