Center of Registers in Region Västra Götaland, Gothenburg, Sweden.
PLoS One. 2012;7(6):e38784. doi: 10.1371/journal.pone.0038784. Epub 2012 Jun 14.
Diabetes is associated with increased cancer risk. The underlying mechanisms remain unclear. Hyperglycemia might be one risk factor. HbA1c is an indicator of the blood glucose level over the latest 1 to 3 months. This study aimed to investigate association between HbA1c level and cancer risks in patients with type 2 diabetes based on real life situations.
This is a cohort study on 25,476 patients with type 2 diabetes registered in the Swedish National Diabetes Register from 1997-1999 and followed until 2009. Follow-up for cancer was accomplished through register linkage. We calculated incidences of and hazard ratios (HR) for cancer in groups categorized by HbA1c ≤ 58 mmol/mol (7.5%) versus >58 mmol/mol, by quartiles of HbA1c, and by HbA1c continuously at Cox regression, with covariance adjustment for age, sex, diabetes duration, smoking and insulin treatment, or adjusting with a propensity score.
Comparing HbA1c >58 mmol/mol with ≤ 58 mmol/mol, adjusted HR for all cancer was 1.02 [95% CI 0.95-1.10] using baseline HbA1c, and 1.04 [95% CI 0.97-1.12] using updated mean HbA1c, and HRs were all non-significant for specific cancers of gastrointestinal, kidney and urinary organs, respiratory organs, female genital organs, breast or prostate. Similarly, no increased risks of all cancer or the specific types of cancer were found with higher quartiles of baseline or updated mean HbA1c, compared to the lowest quartile. HR for all cancer was 1.01 [0.98-1.04] per 1%-unit increase in HbA1c used as a continuous variable, with non-significant HRs also for the specific types of cancer per unit increase in HbA1c.
In this study there were no associations between HbA1c and risks for all cancers or specific types of cancer in patients with type 2 diabetes.
糖尿病与癌症风险增加有关。其潜在机制尚不清楚。高血糖可能是一个危险因素。HbA1c 是过去 1 至 3 个月内血糖水平的指标。本研究旨在根据实际情况，调查 2 型糖尿病患者的 HbA1c 水平与癌症风险之间的关系。
这是一项对 1997 年至 1999 年在瑞典国家糖尿病登记处登记的 25476 例 2 型糖尿病患者的队列研究，随访至 2009 年。通过登记处的链接来完成癌症的随访。我们通过 Cox 回归计算了按 HbA1c ≤ 58mmol/mol（7.5%）与＞58mmol/mol、HbA1c 四分位数和 HbA1c 连续分组的癌症发生率和危险比（HR），并对年龄、性别、糖尿病病程、吸烟和胰岛素治疗进行协方差调整，或用倾向评分调整。
与 HbA1c≤58mmol/mol 相比，使用基线 HbA1c 时，所有癌症的调整 HR 为 1.02（95%CI 0.95-1.10），使用更新的平均 HbA1c 时为 1.04（95%CI 0.97-1.12），且所有癌症和胃肠道、肾脏和泌尿系统、呼吸道、女性生殖器官、乳房或前列腺的特定癌症的 HR 均无统计学意义。同样，与最低四分位数相比，较高四分位数的基线或更新的平均 HbA1c 并未发现所有癌症或特定类型癌症的风险增加。HbA1c 每增加 1%，所有癌症的 HR 为 1.01（0.98-1.04），HbA1c 每增加一个单位的特定癌症的 HR 也无统计学意义。
在这项研究中，2 型糖尿病患者的 HbA1c 与所有癌症或特定类型癌症的风险之间没有关联。
