The Relationship Between the Insulinemic Potential of Diet and Lifestyle and Risk of Breast Cancer: A Case-control Study among Iranian Adult Women.

Introduction: Unhealthy diet and lifestyles play an important role in cancer pathogenesis. We aimed to investigate the association of insulinemic potential of diet and lifestyle with the odds of BC using empirical indices including empirical dietary (EDIH) and lifestyle (ELIH) index for hyperinsulinemia, and empirical dietary (EDIR) and lifestyle (ELIR) index for insulin resistance. Methods: This hospital-based case-control study was conducted among Tehranian adult women aged=30 years. The final analysis was performed on 134 women, newly diagnosed with histologically confirmed BC as a case, and 267 healthy women of the same age as control. A food frequency questionnaire was used for assessing dietary intakes at baseline. Results: The mean±SD of age and BMI of participants were 47.9±10.3 years and 29.4±5.5 kg/m², respectively. EDIH score was remarkably related to the higher risk of BC based on fully adjusted models (OR:2.24;95%CI:1.21-4.12, Ptrend=0.016). Furthermore, subgroup analysis showed a higher BC risk with increasing EDIH score in postmenopausal women (OR:1.74; 95%CI:1.13-2.69) and those without a history of the oral contraceptive pill (OCP) use (OR:1.44;95%CI:1.02-2.04). Moreover, ELIH scores were positively associated with an increased risk of BC in postmenopausal women (OR: 1.98;95% CI: 1.35-2.89), those with a family history of cancer (OR:1.94;95%CI:1.10-3.42), and in individuals who did not use OCP (OR:1.46;95%CI:1.00-2.12). Conclusion: Our results showed a possible link between EDIH and promoted BC risk. Also, higher EDIH and ELIH scores were strongly associated with an increased risk of BC in postmenopausal women, those with a family history of BC, and those who do not use OCP. [ABSTRACT FROM AUTHOR]