During breast cancer (BC), cardiometabolic disorders can worsen prognosis, particularly in women with type 2 diabetes mellitus (T2DM). This study aimed to determine the impact of BC diagnosis on cardiometabolic parameters and the incidence of complication in women over 50 years of age (90% aged ≥ 65 years) with pre-existing T2DM. Using primary care registries from Asturias (Spain), a total of 106 women diagnosed with T2DM followed by BC were selected and matched with women with T2DM (n= 212) in a cohort study. Indicators of cardiometabolic health and microvascular complications associated with T2DM were collected. Women were monitored from two years prior to five years after BC diagnosis. Conditional logistic regressions were used to compare the adjusted odds of staying below each indicator’s threshold. During follow-up, women with T2DM+BC had a higher risk of fasting blood glucose ≥126 mg/dL (adjusted odds ratio [aOR] = 1.83; 95% confidence interval [CI95%]: 1.01–3.32) and glycosylated hemoglobin (Hb1Ac) ≥ 48 mmol/mol or 6.5% (aOR: 2.44; IC95%: 1.21–4.91). There was no difference between the groups regarding the incidence of microvascular complications. BC incidence negatively impacted the glycemic control of Spanish women with pre-existing T2DM measured by basal blood glucose and HbA1c, but not cardiometabolic health indicators or T2DM complications.
在乳腺癌（BC）病程中，代谢性心血管疾病可能恶化预后，尤其对于患有2型糖尿病（T2DM）的女性患者。本研究旨在探讨乳腺癌诊断对50岁以上（其中90%年龄≥65岁）已确诊2型糖尿病女性患者代谢性心血管参数及并发症发生率的影响。基于西班牙阿斯图里亚斯地区初级医疗登记数据，我们在一项队列研究中选取了106名先确诊2型糖尿病后罹患乳腺癌的女性患者，并与212名单纯2型糖尿病患者进行匹配对照。研究收集了代谢性心血管健康指标及与2型糖尿病相关的微血管并发症数据，监测时间跨度涵盖乳腺癌诊断前两年至诊断后五年。通过条件逻辑回归分析比较各组指标维持在阈值以下的校正后比值。随访期间，2型糖尿病合并乳腺癌患者出现空腹血糖≥126 mg/dL（校正比值比[aOR] = 1.83；95%置信区间[CI95%]：1.01–3.32）和糖化血红蛋白（HbA1c）≥48 mmol/mol或6.5%（aOR：2.44；CI95%：1.21–4.91）的风险显著更高。两组在微血管并发症发生率方面未见统计学差异。研究结果表明，乳腺癌发病对已患2型糖尿病的西班牙女性患者的血糖控制（通过基础血糖和HbA1c评估）产生负面影响，但未显著改变其代谢性心血管健康指标或2型糖尿病并发症的发生风险。
肿瘤(癌症)患者之家