Risk of breast cancer in relation to anthropometry, blood pressure, blood lipids and glucose metabolism: a prospective study within the Malmo Preventive Project

Insulin resistance may be a risk factor for breast cancer, possibly through increased levels of oestrogens or insulin-like growth factor I. Insulin re sistance has been associated with obesity, hypertension, dyslipidaemia and impaired glucose tolerance, We studied the relation of these factors to bre ast cancer risk in a prospective cohort study of 9738 women. Menopausal sta tus was defined a priori, and 112 cases of invasive breast carcinoma occurr ed in women who were premenopausal at baseline and 157 cases in subjects wh o were peri/postmenopausal, Relative risks (RR) for breast cancer were calc ulated by Cox's proportional hazards analysis for different quartiles of he ight, weight, body mass index, blood pressure, pulse rate and serum levels of total cholesterol, triglycerides, fasting blood glucose and glucose at 1 20 min after an oral dose of glucose. Peri/postmenopausal women had a signi ficantly increased age-adjusted relative risk of breast cancer associated w ith height (RR = 1.78 for the highest versus lowest quartile), and the RR w as increased over quartiles of cholesterol levels (P-value for trend: 0.05) . No other significant associations were found. Adjustments for potential c onfounding factors or restriction of the analysis to cases and person-years before 55 years of age (premenopausal women), or after 55 years (peri/post menopausal women), did not change these results. (C) 2001 Lippincott Willia ms & Wilkins.