Impact of cancer diagnosis and treatment on glycaemic control among individuals with colorectal cancer using glucose-lowering drugs

Marjolein M. J. Zanders*, Myrthe P. P. van Herk-Sukel, Ron M. C. Herings, Lonneke V. van de Poll-Franse, Harm R. Haak

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


This study aims to evaluate the impact of cancer and its treatment on HbA(1c) values among individuals with colorectal cancer (CRC) using glucose-lowering drugs (GLDs). Patients with primary CRC (1998-2011) were selected from the Eindhoven Cancer Registry and linked to the PHARMO Database Network including outpatient pharmacy and clinical laboratory data. Patients with more than 2 years of GLDs use prior to cancer diagnosis were included. Linear mixed-effects models were conducted to evaluate changes in HbA(1c) for colon cancer (CC) and rectal cancer (RC) patients in the 4 years around CRC diagnosis. Of all CRC patients (n = 4714), 294 (6 %) GLDs users with CC and 144 (3 %) with RC were selected. In the crude model, mean HbA(1c) at cancer diagnosis was 6.9 % (51.6 mmol/mol) among CC patients and 7.1 % (53.5 mmol/mol) among RC patients. Among CC patients, HbA(1c) decreased with 0.12 % per year (p = 0.0002) before cancer diagnosis in the adjusted model, and after diagnosis, it increased with 0.12 % per year (p = 0.02). In subgroup analyses, effects on HbA(1c) were more pronounced in users of anti-anaemic preparations. Among RC patients, HbA(1c) decreased before diagnosis with 0.18 % per year (p = 0.0006), whereas after diagnosis it changed non-significantly. Among users of GLDs, HbA(1c) decreased with 0.12-0.18 % (1-2 mmol/mol) per year before CRC diagnosis. Only among CC patients, HbA(1c) increased after diagnosis (0.12 % per year; 1.3 mmol/mol). Modest changes in HbA(1c) before CRC diagnosis may reflect the effects of an undiagnosed cancer, such as weight loss, anaemia, or the use of anti-anaemic preparations.
Original languageEnglish
Pages (from-to)727-735
JournalActa Diabetologica
Issue number5
Publication statusPublished - Oct 2016


  • HbA(1c)
  • Diabetes mellitus
  • Colorectal cancer
  • Glucose-lowering drugs

Cite this