Volume 214 - Issue 6
Two decades of increasing incidence of childhood‐onset type 2 diabetes in Western Australia (2000–2019)
Authors: Aveni Haynes, Jacqueline A Curran and Elizabeth A Davis
Med J Aust 2021; 214 (6): 285-285.e1. || doi: 10.5694/mja2.50970
Published online: 5 April 2021
Published online: 5 April 2021
To the Editor: This retrospective population‐based study aimed to determine the incidence of type 2 diabetes from 2012 to 2019 in Western Australian youth aged under 16 years, and to examine temporal trends between 2000 and 2019, using data from the Western Australian Children’s Diabetes Database (WACDD).1 The data extracted for eligible patients diagnosed with type 2 diabetes, according to standard criteria,2 included diagnosis year, age, sex and self‐reported Aboriginal or Torres Strait Islander status. Poisson regression was used to determine incidence rates and trends by calendar year, sex, and Aboriginal or Torres Strait Islander status. This study received ethics approval from the Western Australian Child and Adolescent Health Service Human Research Ethics Committee (RGS0000002386).
To ensure the validity of our findings, a secondary aim was to estimate completeness of the WACDD for type 2 diabetes diagnosed in patients aged under 16 years from 1999 to 2016. For this purpose, we used the capture–recapture method with two independent sources: the primary source was WACDD, and the secondary source was the National Diabetes Services Scheme (NDSS) database.3
We identified 224 eligible cases from WACDD (2000–2019), of which 129 (58%) were girls and 128 (57%) were Aboriginal or Torres Strait Islander children. The mean age at diagnosis of type 2 diabetes was 13.2 years (standard deviation, 2.0 years), with no differences observed by sex or Aboriginal or Torres Strait Islander status.
The overall mean incidence was 2.3/100 000 (95% CI, 2.1–2.7), with an average annual increase of 5.2% (95% CI, 2.8–7.8%). No differences were observed in the mean incidence or incidence rate trends between boys and girls. The mean incidence in Aboriginal or Torres Strait Islander children was 18‐fold higher (incidence rate ratio, 18.31; 95% CI, 14.05–23.86) than in non‐Aboriginal or Torres Strait Islander children (Box). In addition, the incidence increased by an annual average of 6.2% (95% CI, 2.8–9.6%) in Aboriginal or Torres Strait Islander children compared with 3.9% (95% CI, 0.3–7.6%) in non‐Aboriginal or Torres Strait Islander children (Box).
Of the 170 eligible cases identified in the WACDD, 107 were ascertained from both WACDD and NDSS, 40 from NDSS only, and 63 from WACDD only. Using the capture–recapture method,3 the WACDD was estimated as 73% complete.
This study provides further evidence for the growing incidence of type 2 diabetes in Australian children and highlights the urgent need for community, public health providers, and government to address this disease and its significant burden in young people.4,5
Box – Case numbers, person years of observation, mean incidence (95% CI) and average annual increase in incidence (95% CI) by Aboriginal or Torres Strait Islander status for youth aged under 16 years diagnosed with type 2 diabetes in Western Australia (2000–2019)
Non‐Aboriginal or Torres Strait Islander |
Aboriginal or Torres Strait Islander |
Combined | |||||||||||||
Cases |
96 (43%) |
128 (57%) |
224 (100%) |
||||||||||||
Sex, female |
54 (56%) |
75 (59%) |
139 (58%) |
||||||||||||
Mean age at diagnosis (SD), years |
13.6 (1.8) |
13.0 (2.1) |
13.2 (1.9) |
||||||||||||
Age range at diagnosis, years |
6.9–15.9 |
6.8–15.9 |
6.8–15.9 |
||||||||||||
Total person years |
8 884 383 |
644 157 |
9 528 540 |
||||||||||||
Mean annual incidence (95% CI) per 100 000 person years |
1.1 (0.9–1.3) |
19.9 (16.6–23.6) |
2.3 (2.1–2.7) |
||||||||||||
Average annual increase in incidence (95% CI) |
3.9% (0.3–7.6%) |
6.2% (2.8–9.6%) |
5.2% (2.8–7.8%) |
||||||||||||
CI = confidence interval; SD = standard deviation. | |||||||||||||||
Competing interests
No relevant disclosures.
References
- Haynes A, Kalic R, Cooper M, et al. Increasing incidence of type 2 diabetes in Indigenous and non‐Indigenous children in Western Australia, 1990–2012. Med J Aust 2016; 204: 303. https://www.mja.com.au/journal/2016/204/8/increasing-incidence-type-2-diabetes-indigenous-and-non-indigenous-children
- American Diabetes Association. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes — 2018. Diabetes Care 2018; 41 (Suppl): S13–S27.
- LaPorte RE, McCarty D, Bruno G, et al. Counting diabetes in the next millennium: application of capture‐recapture technology. Diabetes Care 1993; 16: 528–534.
- Viner R, White B, Christie D. Type 2 diabetes in adolescents: a severe phenotype posing major clinical challenges and public health burden. Lancet 2017; 389: 2252–2260.
- Nadeau KJ, Anderson BJ, Berg EG, et al. Youth‐onset type 2 diabetes consensus report: current status, challenges, and priorities. Diabetes Care 2016; 39: 1635–1642.