title: Age at diagnosis and seasonal variation in the onset of insulin-dependent diabetes in Chile (Southern hemisphere).
abstract: The age at diagnosis, sex, and the date of both the diagnosis (month--year) and the onset of symptoms of 525 insulin-depdendent diabetic patients, under 30 years of age at the time of diagnosis, were collected retrospectively from hospital records. The patients came from Chilean cities located in the Central Zone: Santiago (87%) and Temuco--Concepcion (13%). The age at diagnosis showed a bimodal distribution up to 19 years of age, with the main peak at 12 years and another at 6 years. The female peak preceded the male peak by 1 to 2 years. The onset of symptoms showed a seasonal variation, with the highest frequency in winter and the lowest in spring (P less than 0.01). There was also a significant variation in the time of diagnosis, especially in the 0--19 age group: most cases were diagnosed in winter (June, July) with the lowest number in summer (December).
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002677:Chile; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D007328:Insulin / Q000627:therapeutic use*; D008297:Male; D012621:Seasons; D012737:Sex Factors
chemical_list: D007328:Insulin