Incidence of childhood onset type 1 diabetes in Western Australia from 1985 to 2016: Evidence for a plateau

Abstract

This study provides evidence for a possible plateauing in the incidence of childhood T1D in Western Australia, following a peak in 2003. Ongoing monitoring of the incidence will be essential to determine how temporal trends continue to evolve.

Incidence and trend of type 1 diabetes and the underlying environmental determinants

“…From the geographical point of view, areas beginning with moderate‐low incidences including Croatia, Lesser Poland, Moscow, Belgrade, Nile Delta of northern Egypt, Shanghai city of China, and Korea exhibit a steep escalation of their annual incidences (usually >5% per year and in Shanghai >10% per year). By contrast, stabilization after years of the upward trend has been observed since the first decade of 21st century, mainly in regions already presenting high T1D incidences such as the 3 Nordic countries described above, Ireland, Czech, Biscay, Sardinia, Saudi Arabia, and Western Australia . Besides, incidences in 2 Asian regions with low risk for T1D, Taiwan and Japan, are holding steady as well.…”

“…In addition to the linear temporal trends in the incidence of childhood T1D that have been identified in many populations, nonlinear trends observed in a small part of studies can be attractive as well. In particular, a sinusoidal cyclical variation in the incidence trend of T1D has been reported at both regional and national levels in Australia, with peaks and troughs in incidence occurring approximately every 5 years.…”

“…Generally speaking, a moderate-high incidence of approximately 20/100 000 person-years have been seen in a wide range of Caucasian populations from western and central Europe, 11,17,20,30,[32][33][34] North America, 28 and Oceania. 9,31,42 In contrast to the consistently high incidence rates in Caucasians, incidences of T1D in Arabs range from as high as 40.9/100 000 in Kuwait 27 to 29.0/100 000 in Saudi Arabia 3 to slightly higher than 10/100 000 in Israel. 18 Next come countries in southeast Europe 12,35,[37][38][39] which usually manifest a moderate risk for T1D with incidences around 10/ 100 000 person-years.…”

“…The incidences in these 2 regions are comparable to those of countries in northern Europe. Generally speaking, a moderate‐high incidence of approximately 20/100 000 person‐years have been seen in a wide range of Caucasian populations from western and central Europe, North America, and Oceania . In contrast to the consistently high incidence rates in Caucasians, incidences of T1D in Arabs range from as high as 40.9/100 000 in Kuwait to 29.0/100 000 in Saudi Arabia to slightly higher than 10/100 000 in Israel .…”

“…From the geographical point of view, areas beginning with moderate-low incidences including Croatia, 20 Lesser Poland, 30 Moscow, 37 Belgrade, 39 Nile Delta of northern Egypt, 19 T1D incidences such as the 3 Nordic countries described above, Ireland, 11 Czech, 4 Biscay, 12 Sardinia, 6 Saudi Arabia, 3 and Western Australia. 42 Besides, incidences in 2 Asian regions with low risk for T1D, Taiwan 8 and Japan, 10 are holding steady as well. The flattening of T1D incidence trend observed in 4 countries (regions) between 2000…”