Age at diagnosis and seasonal variation in the onset of insulin-dependent diabetes in Chile (Southern hemisphere)

• Published in: Diabetologia 1979-12, Vol.17 (6), p.357-360
• Main Authors: Durruty, P, Ruiz, F, García de los Ríos, M
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Factors; Child; Child, Preschool; Chile; Diabetes Mellitus, Type 1 - drug therapy; Diabetes Mellitus, Type 1 - epidemiology; Female; Humans; Infant; Insulin - therapeutic use; Male; Seasons; Sex Factors
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/BF01236269

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).