Seasonality of Birth in Children (0-14 Years) with Type 1 Diabetes Mellitus in Slovenia

Abstract

The aim of this study was to find out whether there is seasonality of month of birth of children with diabetes in Slovenia and if so whether it differs from that of the general population. A cohort of 849 children and adolescents (0-14 years) with type 1 diabetes mellitus born between 1956 and 1998 were included in the study. Monthly and seasonal patterns of birth of the patients with diabetes were compared with the pattern of normal live births (n = 1,345,921) and the pattern of disease onset. Statistical analysis was made using Student's t-test to compare the means between the four seasons of the year, and single cosinor analysis for a period of 12 months. The children and adolescents with diabetes had a statistically significant different seasonality of month of birth compared to that of the general population, and an opposite pattern from the seasonality of month of onset of disease. The observations made are in accordance with observations made recently in other countries and support the hypothesis that a virus infection transmitted by the mother to the fetus during the annual viral epidemic induces the autoimmune process in the pancreatic beta-cells in genetically susceptible individuals who will subsequently develop clinical diabetes during childhood.

HbA1c levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions

“…The trend in HbA 1c variation is consistent with seasonal variation of type 1 diabetes incidence [17, 18]. An inverse correlation with ultraviolet irradiance and diagnosis of type 1 diabetes has been observed in Newfoundland, Canada [19].…”

The Role of Vitamin D Deficiency in the Incidence, Progression, and Complications of Type 1 Diabetes Mellitus

“…Consistent results were found in Ukraine (highest variability in western Europe) [81], Sweden [82], Greece [83], Ireland (significant in boys only) [84], Slovenia [85], Germany [86], The Netherlands [87], Britain [88], New Zealand [89], and Sardinia [90]. However, a multicenter cohort study in Europe found no seasonal variations [91].…”

Narcolepsy in Southern Chinese patients: clinical characteristics, HLA typing and seasonality of birth

“…The discrepancy was not clear, but it might be explained by the differential effects of climate and temperature on various geographical areas. Seasonal birth pattern was reported in a number of neuropsychiatric disorders, such as Parkinson’s disease, schizophrenia, bipolar affective disorder and autoimmune disorders such as type 1 diabetes mellitus 40 – 42. It indicated that the seasonal variations of environmental factors, such as nutrition, sunlight, toxins, infectious agents and temperatures, may well be involved in the aetiology of these diseases during early fetal development in subjects with a genetic predisposition.…”