[Influence of energy intake and body mass index in the incidence of cancer of the breast. Case-control study in a sample from 3 Spanish hospital populations].

A case-control study has been designed to analyze the possible role of the energy intake and obesity, judged by the body mass index, on the incidence of breast cancer in a group of 275 women (139 cases and 136 controls), coming from three hospital populations (Madrid, Mérida, and Santiago de Compostela). There are no significant differences in the of cases and controls, which, additionally, does not seem to be significantly related to the risk of breast cancer. On the other hand, the weight and the body mass index of women with breast cancer is significantly higher than that of the controls. The oods ratio, as a measure of the relative risk for breast cancer, shows that a high body mass index behaves as a risk factor (OR = 2.49; 95% IC, = 1.33-4.67, Chi2 = 8.30), a trend which remains after adjusting for energy. When considering the pre or post menopausal status, it is observed that a body mass index higher than 29, adjusted for energy intake, behaves as a risk factor only in the post-menopausal women (OR = 2.28; 95% IC = 0.95-5.46 Chi2 = 3.41).