Insulin resistance in relation to diet, lifestyle, and estrogen profile in Japanese women.

Research Project

Project/Area Number	10670347
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Public health/Health science
Research Institution	Gifu University
Principal Investigator	NAGATA Chisato Gifu University, Public Health, Assistant professor, 医学部, 助手 (30283295)
Co-Investigator(Kenkyū-buntansha)	TAKEDA Noriyuki Gifu University, The Third Department of Internal Medicine, Associate professor, 医学部, 助教授 (20163412) SHIMIZU Hiroyuki Gifu University, Public Health, Professor, 医学部, 教授 (90073139)
Project Period (FY)	1998 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥3,000,000 (Direct Cost: ¥3,000,000) Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
Keywords	Insulin resistance / Estradiol / Diet / Lifestyle
Research Abstract	There is a hypothesis that hyperinsulinemia or insulin resistance may be a mediator for breast cancer risk factors. On the other hand, some but not all of the well-known risk factors of breast cancer have been associated with serum estrogen concentrations. We assessed the relationships of potential breast cancer risk factors to indicators of insulin resistance, fasting plasma insulin concentration and homeostasis model assessment insulin resistance (HOMA-R), in 88 postmenopausal Japanese women. We also examined whether insulin resistance would explain the association of breast cancer risk factors with serum estradiol and sex hormone-binding globulin (SHBG). Information on potential breast cancer risk factors such as demographic characteristics, smoking and drinking habits, diet, exercise, menstrual and reproductive factors were obtained by self-administered health questionnaire including validated semiquantitative food frequency questionnaire. Body mass index (BMI) was significantly correlated with the ratio of estradiol to SHBG, fasting plasma insulin, and HOMA-R after controlling for age. The correlations were still significant between BMI and estradiol/SHBG ratio after controlling for fasting plasma insulin and between BMI and fasting plasma insulin as well as HOMA-R after controlling for estradiol/SHBG ratio. There is a possibility that effect of BMI on breast cancer risk is mediated by both insulin resistance and estrogen metabolism.