Increasing Incidence and Age at Diagnosis among Children with Type 1 Diabetes Mellitus over a 20-Year Period in Auckland (New Zealand)

BACKGROUND: We aimed to evaluate the incidence of type 1 diabetes mellitus in children <15 years of age (yr) in the Auckland region (New Zealand) over 20 years (1990-2009). METHODS: We performed a retrospective review of all patients <15 yr diagnosed with type 1 diabetes, from an unselected complete regional cohort. RESULTS: There were 884 new cases of type 1 diabetes, and age at diagnosis rose from 7.6 yr in 1990/1 to 8.9 yr in 2008/9 (r(2) = 0.31, p = 0.009). There was a progressive increase in type 1 diabetes incidence among children <15 yr (p<0.0001), reaching 22.5 per 100,000 in 2009. However, the rise in incidence did not occur evenly among age groups, being 2.5-fold higher in older children (10-14 yr) than in the youngest group (0-4 yr). The incidence of new cases of type 1 diabetes was highest in New Zealand Europeans throughout the study period in all age groups (p<0.0001), but the rate of increase was similar in New Zealand Europeans and Non-Europeans. Type 1 diabetes incidence and average annual increase were similar in both sexes. There was no change in BMI SDS shortly after diagnosis, and no association between BMI SDS and age at diagnosis. CONCLUSIONS: There has been a steady increase in type 1 diabetes incidence among children <15 yr in Auckland over 20 years. Contrary to other studies, age at diagnosis has increased and the greatest rise in incidence occurred in children 10-14 yr. There was little change in BMI SDS in this population, providing no support for the 'accelerator hypothesis'

Early Markers of Glycaemic Control in Children with Type 1 Diabetes Mellitus

Background: Type 1 diabetes mellitus (T1DM) may lead to severe long-term health consequences. In a longitudinal study, we aimed to identify factors present at diagnosis and 6 months later that were associated with glycosylated haemoglobin (HbA 1c) levels at 24 months after T1DM diagnosis, so that diabetic children at risk of poor glycaemic control may be identified. Methods: 229 children,15 years of age diagnosed with T1DM in the Auckland region were studied. Data collected at diagnosis were: age, sex, weight, height, ethnicity, family living arrangement, socio-economic status (SES), T1DM antibody titre, venous pH and bicarbonate. At 6 and 24 months after diagnosis we collected data on weight, height, HbA 1c level, and insulin dose. Results: Factors at diagnosis that were associated with higher HbA1c levels at 6 months: female sex (p,0.05), lower SES (p,0.01), non-European ethnicity (p,0.01) and younger age (p,0.05). At 24 months, higher HbA1c was associated with lower SES (p,0.001), Pacific Island ethnicity (p,0.001), not living with both biological parents (p,0.05), and greater BMI SDS (p,0.05). A regression equation to predict HbA1c at 24 months was consequently developed. Conclusions: Deterioration in glycaemic control shortly after diagnosis in diabetic children is particularly marked in Pacific Island children and in those not living with both biological parents. Clinicians need to be aware of factors associated wit

Incidence of new cases of type 1 diabetes mellitus per 100,000 age-matched inhabitants diagnosed in Auckland (New Zealand) during 1990–2009.

<p>A) For all children &lt;15 yr; B) for children 0–4 yr (solid gray line), 5–9 yr (dashed gray line), and 10–14 yr (solid black line).</p

Changes in the age-specific incidence of type 1 diabetes mellitus per 100,000 in children &lt;15 years of age (yr) in the Auckland region in 1990–2009.

<p>Changes in the age-specific incidence of type 1 diabetes mellitus per 100,000 in children &lt;15 years of age (yr) in the Auckland region in 1990–2009.</p

Demographic characteristics of subjects at diagnosis.

<p>Where applicable, data are mean ± SEM.</p><p>*p&lt;0.05,</p><p>**p&lt;0.01, and</p><p>***p&lt;0.001 for comparisons between groups. Different letters indicate significant differences (p&lt;0.05) between groups.</p