Young-Onset Type 2 Diabetes in the Auckland Region - Clinical Outcomes and Healthcare Service Use in Comparison to Type 1 Diabetes

Abstract

Objectives: Investigate clinical outcomes and healthcare service use in young-onset (15-30 years-of-age) type 2 diabetes (T2D) in comparison to type 1 diabetes (T1D). Methods: Retrospective study including 731 people with T1D and 1350 with T2D, analysing complications, risk-factors, medication dispensing, primary-care visits, diabetes clinic attendance, hospital admissions. A national index of deprivation (NZDep) was used to assess the impact of socioeconomic deprivation. Results: The median duration of known diabetes was 8 years for both groups. A greater proportion of the T2D group lived in the most deprived NZDep deciles (9&10) (58% vs 28% of T1D, p<0.001). 46% of people with T2D had a urine albumin:creatinine (ACR) >3.5 mg/mmol in the year of diagnosis, increasing to 61% 8 years later. Logistic regression with established risk factors (including BMI) showed: T2D (OR 2.72, 95% CI 1.95-3.80), NZDep (OR 1.07, 95% CI 1.06-1.12), Māori (OR 2.64, 95% CI 1.79-3.89), Pasifika (OR 2.64, 95% CI 1.79-3.88), Indian (OR 2.50, 95% CI 1.52 to 4.52, p=0.0003) and Asian ethnicities (OR 1.83, 95% CI 1.08-3.10) were more likely to have a higher ACR. NZDep (OR 1.12, 95% CI 1.07-1.77), Pasifika (OR 2.62, 95% CI 1.81-3.80, p<0.0001), Māori (OR 2.22, 95% CI 1.55-3.19, p<0.0001), and Asian ethnicities (OR 0.61, CI 0.38-0.95) influenced the likelihood of having a HbA1c >64 mmol/mol. The median 5-year CVD risk was significantly higher for T2D (8.1% vs 4.9%, p<0.001). Adjusted for HbA1c, and NZDep, Pasifika (OR 2.79, 95% CI 1.43-5.44) and Māori (OR 2.05, 95% CI 1.03-4.09) were more likely to have a delayed (>1 year after diagnosis) referral to diabetes services. The median number of appointments offered over 2 years was greater for T1D (2.0 (IQR 0, 7) vs 0 (IQR 0, 2), p<0.001); non-attendance increased with NZDep for T2D (p=0.016). The proportion with hospital admissions was similar in both groups, with higher rates of admission with increasing NZDep (T1D p<0.001, T2D p=0.015). Over a 6-month period, 31% of those with an HbA1c >100mmol/mol were not dispensed any hypoglycaemic medication, 27% of those with cerebrovascular/cardiovascular/peripheral vascular disease were not dispensed a statin, and 30% with ACR >30mg/mmol were not dispensed an ACE inhibitor/angiotensin receptor blocker. Conclusions: A comprehensive strategy is needed to better manage young-onset T2D addressing socioeconomic disparities.