Seasonal Variation in the Diagnosis Onset of Type 1 Diabetes Mellitus in Children and Adolescents in Cameroon - Abstract
Background: Although the seasonality of type 1 diabetes has been described in most regions of the world, there are few data from sub-Saharan Africa. The aim of this study was to determine if there is a seasonality in the occurrence of type 1 diabetes, based on the “Changing Diabetes in Children” (CDiC) registry where all cases of type 1 diabetes in children and adolescents in Cameroon are registered since 2010. Methods: We identified the files of all children and adolescents enrolled in the CDiC project between October 2010 and December 2015. For each participant, we gathered information concerning demographic data and history of diabetes. In addition, we collected for each case the region of residence at the time of diagnosis, with the precipitation and temperature data corresponding to the month and year of diagnosis. A month was dry if the average monthly rainfall was <100mm and wet if the average monthly rainfall was ? 100mm. The data were analyzed using SPSS (Statistical Package for Social Sciences) software version 20.0. Results: Fourth hundred forty-six patients were included in the study. We found a repeating trends over the years with a low number of cases diagnosed during dry months (March to May) and a higher number of cases during wet months (August to October). Overall, most of the diabetes new cases occurred between August and November with a peak in September (69/446), while the lowest number of cases were diagnosed in April and May (23/446). There was a positive correlation between the number of new T1DM cases and the rainfall and a negative correlation with the mean temperature. Conclusion: Our data support the existence of a clear seasonal pattern in the onset and diagnosis of type 1 diabetes mellitus in Cameroon. Most of the new cases appear between August and October, which represent the cold and wet months.