BMJ Open 2:e000433 doi:10.1136/bmjopen-2011-000433
  • Diabetes and endocrinology
    • Research

Risk of cancer in patients using glucose-lowering agents: a nationwide cohort study of 3.6 million people

  1. Christian Torp-Pedersen1,4
  1. 1Department of Cardiology, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
  2. 2Department of Endocrinology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
  3. 3Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
  4. 4Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
  1. Correspondence to Dr Charlotte Andersson; ca{at}
  • Received 5 October 2011
  • Accepted 10 May 2012
  • Published 8 June 2012


Objectives To study the association between exposures to glucose-lowering therapy and risk of cancer using the nationwide administrative registers in Denmark.

Design Nationwide cohort study.

Setting All hospitals in Denmark.

Participants All individuals aged ≥35 years in 1998–2009 who were naive to glucose-lowering treatment and had no history of cancer. Primary measures outcomes: first cancer diagnosis between 1998 and 2009. The RR of cancer as dependent on exposure to individual glucose-lowering agents was assessed by multivariable Poisson regression models.

Results Of 159 894 patients that initiated treatment with glucose-lowering agents, 12 789 developed cancer, incidence rate 17.4/1000 person-years. Of the remaining 3 447 904 individuals not using glucose-lowering agents, 293 878 developed cancer, incidence rate 7.9/1000 person-years. Use of different types of glucose-lowering agents including human insulin, insulin analogues, as well as sulfonylureas were associated with a quantitatively similar and significantly increased RR of cancer of 1.2–1.3 compared with unexposed individuals after multivariable adjustment. For the majority of agents, the authors identified the highest RR of cancer during the first 30 treatment days with a subsequent decline of risk approaching the cancer risk of the background population only 6–12 months after initiation of treatments.

Conclusions Use of most glucose-lowering agents including sulfonylureas was associated with a comparable increased risk of cancer shortly after initiation of treatment and subsequently a decline to the risk of the background population. This suggests that the relation is not causal.


  • To cite: Andersson C, Vaag A, Selmer C, et al. Risk of cancer in patients using glucose-lowering agents: a nationwide cohort study of 3.6 million people. BMJ Open 2012;2:e000433. doi:10.1136/bmjopen-2011-000433

  • Contributors All authors contributed to conception and design. C.A. and C.T.-P. performed the data analyses. C.A. and C.T.-P. had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. C.A., A.V. and C.T.-P. drafted the article and all authors revised it critically for important intellectual content (C.A., A.V., C.S., M.S., R.S., J.L., G.H.G., L.K. and C.T.-P.). All authors approved the final version to be published.

  • Funding This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests All authors report no potential conflicts of interest, but it should be mentioned that Dr AV was previously employed by Steno Diabetes Center, which is owned by Novo Nordisk.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Unfortunately not doable.

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