체질량지수와 유방암발생의 관련성

Objectives: This study investigated the association between body mass index (BMI) (and its change) and risk of breast cancer in Korea women by age. Methods: Participants were 64,149 women aged 35~59 years at the baseline (1990~1992) of the Korea Medical Insurance Corporation study. They were stratified as 44,923 women aged 37~47 years and 19,226 women aged 48~61 years by age at year 1992. BMI change was defined as BMI at 1994 minus baseline BMI. Baseline BMI was categorized quartile and first quartile used as reference group for the analysis. BMI change was categorized quartile and second quartile used as reference group for the analysis. Hazard ratio (HR) calculated using Cox`s proportional hazard model. Results: Baseline BMI and breast cancer risk were not associated in women aged < 48 (HR = 0.83, p for trend = 0.182 for Q4 vs Q1), but associated in women aged ≥ 48 (HR = 2.08, p for trend = 0.002 for Q4 vs Q1). However, BMI change was not associated with breast cancer risk in either age group. Conclusions: These results suggest that obesity may be a risk factor breast cancer in premenopausal women but not in post menopausal women.