Impact of sex and age at onset of diabetes on mortality from ischemic heart disease in patients with type 1 diabetes

  1. Per-Henrik Groop, MD DMSc1,2,6
  1. 1Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, Haartmaninkatu 8, P.O Box 63, FIN-00014 Helsinki, Finland
  2. 2Division of Nephrology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
  3. 3National Institute for Health and Welfare, Diabetes Prevention Unit, Helsinki, Finland
  4. 4Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, USA
  5. 5Women’s Health Research Center, University of Mississippi Medical Center, Jackson, MS 39216, USA
  6. 6The Baker IDI Heart and Diabetes Institute, Melbourne, Australia
  1. Corresponding author: Valma Harjutsalo, E-mail: valma.harjutsalo{at}helsinki.fi

Abstract

Objective Our aim was to study whether ischemic heart disease (IHD) mortality among patients with type 1 diabetes (T1D) depends on the age at onset of diabetes and whether this effect is sex-specific.

Research design and methods The study examined long-term IHD-specific mortality in a Finnish population-based cohort of patients with early-onset (0-14 years) and late-onset (15-29 years) type 1 diabetes (n=17,306).

Results During 433,782 person years of follow-up, 478 IHD deaths were observed. Within the early-onset cohort, the average crude mortality rate in women was 33.3% lower compared with men while in the late-onset cohort mortality was only half of that in men. In contrast, standardized mortality ratio (SMR) was higher in women than men; 21.6 (95% CI 17.2-27.0) for women compared with 5.8 (95% CI 5.1-6.6) for men. The difference between sexes was more striking in the early-onset cohort; SMR for women was 52.8 (95% CI 36.3-74.5) and 12.1 (95% CI 9.2-15.8) for men. SMR was greater in women also in the late-onset cohort, being 15.8 (95% CI 11.8-20.7) compared with men 5.0 (95% CI 4.3-5.8). The relative risk of dying from IHD was greatest in women under 40 years and 40-60 years in the early and late-onset cohort, respectively.

Conclusion The risk of mortality from IHD is exceptionally high in women with early-onset T1D compared with women in the background population. These observations underscore the importance of identifying risk factors early in women and more aggressive treatment following diagnosis.

  • Received February 14, 2013.
  • Accepted August 12, 2013.

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  1. Diabetes Care
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