Article Text
Background
Socioeconomic status in the risk of developing type 1 diabetes seems inconsistent. We investigated whether risk of childhood-onset type 1 diabetes differed by parental education or occupation in a nationwide cohort.
Methods This cohort study included all children born in Norway from 1974 to 2013. In individually linked data from nationwide population registries following children born in Norway up to 15 years of age, we identified 4647 with newly diagnosed type 1 diabetes during 15 381 923 person-years of follow-up.
Results Children of mothers with a master’s degree had lower risk of type 1 diabetes than children of mothers with completed upper secondary education only (adjusted incidence rate ratio, aIRR=0.82 95% CI: 0.70 to 0.95). There was no difference between upper secondary and lower secondary maternal education (aIRR=0.98, 95% CI: 0.89 to 1.08). Paternal education was not significantly associated with type 1 diabetes, lower secondary compared with upper secondary aIRR 0.96 (0.88–1.05) and master compared with upper secondary aIRR 0.93 (0.83–1.05). While maternal elementary occupation was associated with a lower risk of type 1 diabetes, specific maternal or paternal occupations were not.
Conclusions Our results suggested inverse U-shaped associations between maternal socioeconomic status and risk of type 1 diabetes. Non-linear associations may be part of the reason why previous literature has been inconsistent.
- DIABETES MELLITUS
- EDUCATION
- CHILD HEALTH
Data availability statement
Data may be obtained from a third party and are not publicly available. Norwegian data protection legislation and Act on medical andhealth research do not allow individual level patient data to be shared by the authors. However, all data are accessible to authorised researchers after ethical approval andapplication to the registries via https://helsedata.no/, and the Norwegian Childhood Diabetes Registry.
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Data availability statement
Data may be obtained from a third party and are not publicly available. Norwegian data protection legislation and Act on medical andhealth research do not allow individual level patient data to be shared by the authors. However, all data are accessible to authorised researchers after ethical approval andapplication to the registries via https://helsedata.no/, and the Norwegian Childhood Diabetes Registry.
Footnotes
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Contributors LCS and GJ conceptualised the study and research question. GJ, LCS and SEH were responsible for data acquisition, planning and funding. LCS and PL-DR conceptualised the detailed study design. PL-DR, GT and IJB carried out the data preparation. PL-DR and LCS did the statistical analyses with input and quality control by GT. All authors contributed to the interpretation of results. PL-DR wrote the first draft of the manuscript and subsequent revisions. All authors critically revised the paper for important intellectual content and approved the final version. PL-DR and LCS are guarantors. They had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Funding This research was funded in part by a grant from the South-Eastern Norway Regional Health Authority and by the Norwegian Institute of Public Health, and in part by the Research Council of Norway through its Centers of Excellence funding scheme, project number 262700.
Competing interests PL-DR reports participation in a research project funded by LEO Pharma, all regulator mandated phase IV studies, all with funds paid to her institution (no personal fees) and with no relation to the work reported in this paper. All other authors declare no competing interests.
Provenance and peer review Not commissioned; externally peer reviewed.
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