我们在护士健康研究 (NHS) 和 NHS2 中的研究（一项包含 1260 例病例和 2221 名对照的巢式病例对照研究）调查了 C 肽水平、乳房 X 光密度 (MD) 参数、V（灰度测量值）之间的关联变异）和乳腺癌（BC）风险。我们还研究了 C 肽和 BC 风险在乳房 X 线摄影特征四分位数之间的变化。使用线性和逻辑回归来研究 C 肽和 MD 参数与乳腺癌之间的关联。 C 肽与 MD 百分比呈负相关，与非致密面积呈正相关，但与致密面积和 V 测量值没有关联。 C 肽与侵袭性 BC 风险增加相关（顶部与底部四分位数，比值比 = 1.46，95% CI：1.12-1.91）。 C 肽、MD 参数和 BC 风险之间未发现乘性相互作用。我们的结果表明 C 肽与 BC 风险之间存在正相关，而 MD 参数似乎并未改变这种相关性。© 2024。作者。

Our study in the Nurses' Health Study (NHS) and NHS2, a nested case-control study with 1260 cases and 2221 controls, investigated the association between C-peptide levels, mammographic density (MD) parameters, V (a measure of gray scale variation), and breast cancer (BC) risk. We also examined how C-peptide and BC risk vary across quartiles of mammographic features. Linear and logistic regressions were used to study the associations between C-peptide and MD parameters, and breast cancer. C-peptide was inversely associated with percent MD and positively with non-dense area, but no associations were found with dense area and V measure. C-peptide was associated with an increased risk of invasive BC risk (top vs. bottom quartile, odds ratio = 1.46, 95% CI: 1.12-1.91). No multiplicative interactions were found between C-peptide, MD parameters, and BC risk. Our results suggest a positive association between C-peptide and BC risk, and MD parameters do not seem to modify this association.© 2024. The Author(s).