Professor Naja Hulvej Rod
Section of Epidemiology, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen
Professor Marit Eika Jørgensen
Clinical Epidemiology, Steno Diabetes Center Copenhagen & University of Southern Denmark
Senior Statistician Bendix Carstensen
Clinical Epidemiology, Steno Diabetes Center Copenhagen
Associate Professor Jannet Svensson
Department of Paediatrics and Adolescent Medicine, Copenhagen University Hospital, Herlev
Professor Rikke Lund (Chairperson)
Section of Social Medicine, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
Professor Sarah Wild
Usher Institute, University of Edinburgh
Clinical Associate Professor Reimar W. Thomsen
Department of Clinical Epidemiology, Aarhus University.
Knowledge of the non-genetic risk factors of type 1 diabetes is sparse, but persons with type 1 diabetes and their relatives are often concerned that stressful adverse life events or circumstances have contributed to the development of the disease.
Childhood adversities cover a broad range of stressful adverse life events and circumstances from material deprivation to straining family dynamics. The overall objective of this PhD project was to document the level of childhood adversities across age, sex, and social strata in Denmark and, based on this knowledge, thoroughly assess the effects of accumulation of adversities across childhood and adolescence on type 1 diabetes risk in males and females separately. To do this, a large register-based cohort including all children born in Denmark since 1980 (N=2,223,927) was set up with annually registered information on exposure to social and family-related adversities. The study population was followed for 16.8 years on average, during which 8335 persons developed type 1 diabetes.
The results showed that even in a welfare state like Denmark, exposure to childhood adversities is common; more than half of the study population experienced at least one childhood adversity, and one in 10 children experienced three or more adversities before the age of 18 years.
Contrary to the expected, accumulation of childhood adversities was not associated with type 1 diabetes in the vast majority of the study population. A small group of children (3%) exposed to high and increasing annual rates of childhood adversities across childhood and adolescence had a higher risk of developing type 1 diabetes, but only among males who were diagnosed before 11 years of age and among females diagnosed after 16 years of age.
I conclude that exposure to childhood adversities is generally not an important risk factor for type 1 diabetes, which may be reassuring to persons who are concerned that stressful adverse experiences have contributed to the development of the disease. However, exposure to childhood adversities have well-documented consequences for many other mental and physical health outcomes and, given their relatively high prevalence, should be considered a public health issue. Strategies to reduce the prevalence and effects of childhood adversities are therefore warranted.