Correlation of worldwide incidence of type 1 diabetes (DiaMond) with prevalence of asthma and atopic eczema (ISAAC)


  • Authorship and contributorship P. Fsadni and C. Fsadni designed and carried out thestudy and wrote paper. S. Fava and S. Montefort conceived and designed the study, analysed data and corrected manuscript.

  • Ethics This study has been performed in accordance with the ethical standards laid down in the Declaration of Helsinki. All patients provided written informed consent prior to their inclusion in the study.

  • Conflict of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article.

Peter Fsadni, MD, MRCP(UK), Department of Medicine, Mater Dei Hospital, Tal-Qroqq, Msida MSD2090, Malta, Tel: +356 79091642, Fax: +356 2545 4514. email:


Introduction:  Environmental factors play a role in pathogenesis of both type 1 diabetes and atopic disease but they remain incompletely understood. T cell-mediated responses primarily of the T helper type 1 (Th1) are involved in type 1 diabetes while T helper type 2 (Th2) responses favour allergic disease. This TH 1/TH 2 paradigm is currently the source of much controversy in various studies.

Objective:  The aim of the study was to compare the reported country incidence of type 1 diabetes with the prevalence of atopic disease.

Methods:  The prevalence of wheeze, rhinitis, rhinoconjunctivitis and atopic eczema in the preceding 12 months in the 13- to 14-year-old age group was taken from The International Study of Asthma and Allergies in Childhood phase 1 study. These were compared to the age specific incidence of type 1 diabetes in children per 100 000 per year obtained from the Diabetes Mondiale Project Group study from those countries participating in both studies. Data collected from these 31 countries together with latitude was analysed using a Pearson correlation and significance analysis. A multiple regression analysis determined the confounding effect of latitude.

Results:  The incidence of type 1 diabetes was found to have a positive correlation with both wheezing (P = 0.009) and atopic eczema (P < 0.01). There was a no correlation between the incidence of type 1 diabetes and the prevalance of rhinitis (r = 0.02, P = 0.88) or of rhinoconjunctivitis (r = 0.026, P = 0.88). Latitude correlated negatively with type 1 diabetes and positively with rhinitis and rhinoconjnctuvits; it was not significantly correlated with wheeze or eczema. Regression analysis showed that latitude is a significant confounding factor in the correlation of rhinitis (P value <0.0008) and rhinoconjunctivitis (P value <0.0003) with diabetes.

Conclusions:  The study suggests that common environmental and/or genetic factors predispose to type 1 diabetes, wheezing and atopic eczema while factors predisposing to rhinitis and rhinoconjunctivitis appear to be distinct from those predisposing to type 1 diabetes.

Please cite this paper as: Fsadni P, Fsadni C, Fava S and Montefort S. Correlation of worldwide incidence of type 1 diabetes (DiaMond) with prevalence of asthma and atopic eczema (ISAAC). Clin Respir J 2012; 6: 18–25.