Incidence rate and spatio-temporal clustering of type 1 diabetes in Santiago, Chile, from 1997 to 1998

Abstract

ObjectiveTo estimate the incidence rate of type 1 diabetes in the urban area of Santiago, Chile, from March 21, 1997 to March 20, 1998, and to assess the spatio-temporal clustering of cases during that period. Methods All sixty-one incident cases were located temporally (day of diagnosis) and spatially (place of residence) in the area of study. Knox's method was used to assess spatiotemporal clustering of incident cases. ResultsThe overall incidence rate of type 1 diabetes was 4.11 cases per 100,000 children aged less than 15 years per year (95% confidence interval: 3.06-5.14). The incidence rate seems to have increased since the last estimate of the incidence calculated for the years 1986-1992 in the metropolitan region of Santiago. Different combinations of space-time intervals have been evaluated to assess spatio-temporal clustering. The smallest p-value was found for the combination of critical distances of 750 meters and 60 days (uncorrected p-value = 0.048). Conclusions Although these are preliminary results regarding space-time clustering in Santiago, exploratory analysis of the data method would suggest a possible aggregation of incident cases in space-time coordinates. Resumo Objetivo97 97 97 97 Rev Saúde Pública 2001;35(1):96-100 www.fsp.usp.br/rsp Incidence rate and spatio-temporal of type 1

Space–time clustering analyses of type 1 diabetes among 0- to 29-year-olds in Yorkshire, UK

“…Three studies from Sweden and one from Chile have found space-time clustering of type 1 diabetes in children [9][10][11][12], whilst a further study from France found no evidence of space-time clustering [13]. Only one of these studies made an adjustment for arbitrary boundaries [11].…”

Are low sun exposure and/or vitamin D risk factors for type 1 diabetes?

“…Seasonality of diagnosis of T1D has been extensively studied and reported in both northern 114,122,133,[141][142][143][144][145] and southern hemisphere studies. 31,141,[146][147][148][149][150][151] In many countries, seasonality of diagnosis follows a cyclic, sinusoidal pattern 149 with a peak occurring in cooler winter months, 143,[148][149][150][152][153][154] or late autumn/ winter 122,141,155 and a nadir in spring and summer. 122,143,155 Unlike month of birth, seasonality of diagnosis is now a wellrecognised feature of T1D in childhood.…”

La metilación global del ADN y los niveles de homocisteína en plasma se encuentran disminuidos en pacientes con diabetes mellitus tipo 1

“…Es comúnmente diagnosticada en niños, adolescentes y adultos jóvenes [1][2][3][4] . La incidencia de esta patología ha aumentado en las últimas décadas tanto en Chile 5,6 como a nivel mundial 7 . Este aumento, sin embargo, no se ha acompañado de una mayor frecuencia en los genotipos que confieren mayor riesgo, sino más bien de una disminución de ellos 8 .…”