Clinical Characteristics, Glycemic Control, and Microvascular Complications Compared Between Young-Onset Type 1 and Type 2 Diabetes Patients at Siriraj Hospital – A Tertiary Referral Center

PURPOSE: This study aimed to investigate the clinical characteristics, glycemic control, and microvascular complications compared between young-onset type 1 (T1DM) and type 2 diabetes (T2DM) patients at Siriraj Hospital. PATIENTS AND METHODS: We collected demographic, clinical, glycemic control, and microvascular complication data of young-onset (onset <30 years of age) T1DM and T2DM patients at our center using February 2019-December 2020 data from the Thai Type 1 Diabetes and Diabetes diagnosed Age before 30 years Registry, Care and Network (T1DDAR CN). RESULTS: Of 396 patients, 76% had T1DM and 24% had T2DM. At diagnosis, T1DM were significantly younger (9.7±5.4 vs 16.9±6.4 years, p<0.001), had a lower body mass index (17.2±4.1 vs 30.8±7.9 kg/m(2), p<0.001), higher prevalence of diabetic ketoacidosis (DKA) (66.1% vs 13.7%, p<0.001), and higher HbA(1c) level (12.8±2.6% vs 10.9±3.1%, p=0.002) compared to T2DM. Regarding glycemic control, the mean HbA(1c) at registry enrollment did not differ between groups (T1DM 8.3±1.8% vs T2DM 8.1±2.2%, p=0.303), but T1DM achieved HbA(1c) <7% significantly less than T2DM (19.3% vs 47.8%, p<0.001). T1DM showed deterioration of glycemic control during 10–20 years of age, and gradually improved during 20–30 years of age, whereas patients with T2DM showed progressive worsening of glycemic control over time. Concerning microvascular complications, the prevalence of diabetic retinopathy (10.6% vs 9%, p=0.92) and diabetic neuropathy (3.4% vs 5.5%, p=0.514) between T1DM and T2DM was not significantly different. However, T2DM had a significantly higher prevalence of diabetic nephropathy (T1DM 10.1% vs T2DM 40.2%, p<0.001) that developed within a significantly shorter duration of diabetes (T1DM 11.0±6.8 vs T2DM 4.3±5.1 years, p<0.001) compared to T1DM. CONCLUSION: T1DM had a significantly high prevalence of DKA at presentation, and most T1DM did not achieve the glycemic target, especially during adolescence. T2DM had a significantly higher prevalence of diabetic nephropathy that developed within a shorter duration of diabetes compared to T1DM.