[ 74 ] found that the prevalence of ER-negative breast cancer was higher in their diabetic patients compared with the non-diabetic group; however, although the small difference, 32.2% versus 30.6%, was statistically highly significant ( p < 0.001), this may have been affected beyond its biological influence by the large sample sizes.
[ 41 ] confirmed this independent association when they showed that in two groups with an equally severe degree of obesity (BMI 45.0 ± 1.3 kg/m 2 ), those with insulin resistance had pronounced macrophage infiltration of visceral adipose tissue and elevated serum CRP and reduced serum adiponectin concentrations; a higher serum IL-6 level in the insulin resistant group did not reach statistical significance ( p = 0.08).
[ 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.