INS and breast cancer: Also, a nested case-control study by Borugian et al. [67] found that when comparing the highest and lowest tertiles, non-fasting serum insulin concentrations showed a trend, although not statistically significant at the 0.05 level, for a positive correlation with breast cancer mortality in postmenopausal (odds ratio, 1.9; 95% confidence interval, CI, 0.7–6.6, p trend = 0.10), but not premenopausal (odds ratio, 0.9; 95% CI, 0.3–2.9, p trend = 0.75) women.