Environmental determinants of type 1 diabetes: A role for overweight and insulin resistance

Authors

  • Sadia T Islam,

    1. Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
    2. School of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia
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  • Shubha Srinivasan,

    1. Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
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  • Maria E Craig

    Corresponding author
    1. Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
    2. School of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia
    3. Discipline of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales, Australia
    • Correspondence: Associate Professor Maria E Craig, Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia. Fax: +61 2 9845 3170; email: m.craig@unsw.edu.au

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  • Conflict of interest: None declared.

Abstract

Rates of type 1 diabetes are rising globally, with a decreasing proportion of high-risk genotypes and twin concordance rates below 50%. Therefore, environmental factors such as viruses, nutrition and overweight have been examined as putative aetiological agents. The accelerator hypothesis proposes that overweight and insulin resistance are central to both type 1 and type 2 diabetes and may explain, in part, the rise in type 1 diabetes incidence. The temporal rise in body mass index at type 1 diabetes onset and the observation that pre-diabetic children are heavier and more insulin resistant than their peers suggests convergence of type 1 and type 2 diabetes phenotypes. The influence of insulin resistance may begin in utero, although the aetiological role of birthweight in type 1 diabetes remains unclear. Further research to elucidate the role of these modifiable risk factors in today's obesogenic environment may provide future potential for diabetes prevention.

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