The association between obesity related adipokines and risk of breast cancer: a meta-analysis

The risk of breast cancer is significantly increased among obese women as the deleterious adipokines can be over secreted and beneficial adipokines can be hyposecreted. We aim to evaluate the association between obesity-associated adipokines and breast cancer. We searched PubMed, EMBASE, Web of Science, and Chinese Biomedical Literature (CBM) databases for studies reporting association of obesity related adipokines with breast cancer published before Sept. 15, 2015. Initially, 26783 publications were identified, and later, 119 articles were selected for further meta-analysis. Out of these 119 studies, twenty-six studies had reported adipokine levels among obese and non-obese healthy subjects and ninety-three studies had reported adipokine levels among patients with breast cancer. The subjects with BMI >25 kg/m2 had significantly lower adiponectin levels and higher leptin and tumor necrosis factor-α (TNF-α) levels than those with BMI <25 kg/m2. Decreased concentrations of adiponectin, and increased concentrations of leptin, IL-6, IL-8, TNF-α, resistin and visfatin were significantly associated with risk of breast cancer. Adipokine levels were strongly associated with breast cancer among Asian women as compared to non-Asian women. Our results might explain the relationship of obesity, adipokine levels and risk of breast cancer, especially in Asian women.