ESPEYB18 10. Type 1 Diabetes Mellitus (1) (14 abstracts)
Diabetes Care. 2020; 43:8289. doi: 10.2337/dc19-0747.
It is often difficult to identify maturity-onset diabetes of the young (MODY) in pediatric patients close to diabetes onset. Hence, misdiagnosis and unnecessary insulin treatment are still common.
This study reports the discriminatory clinical features at diabetes onset in Swedish pediatric patients (age 118 years) with glucokinase (GCK), hepatocyte nuclear factor-1A (HNF1A), and HNF4A forms of MODY. Children (n=3,933) diagnosed with diabetes between May 2005 to December 2010, were identified from the national consecutive prospective cohort, Better Diabetes Diagnosis. Clinical data, islet autoantibodies (GAD insulinoma antigen-2, zinc transporter 8, and insulin autoantibodies), HLA type, and C-peptide were collected at diagnosis. GCK, HNF1A, and HNF4A genes were sequenced through either routine clinical or research testing.
The minimal prevalence of MODY was 1.2%. Discriminatory factors for MODY at diagnosis included negativity for four islet autoantibodies (100% in MODY vs. 11% in non-MODY), lower HbA1c (7.0% vs. 10.7% [53 vs. 93 mmol/mol]), lower plasma glucose (11.7 vs. 26.7 mmol/l), more likely parental diabetes (63% vs. 12%), and less likely diabetic ketoacidosis (0% vs. 15%). Sequencing of the 303 autoantibody-negative patients identified 46 patients with MODY (detection rate 15%). Limiting testing to the 73 patients with islet autoantibody-negativity and HbA1c <7.5% (58 mmol/mol) at diagnosis identified 36/46 (78%) patients with MODY (detection rate 49%). On follow-up, the 46 patients with MODY had excellent glycemic control (mean HbA1c 6.4%; 47 mmol/mol) with 42/46 (91%) not on insulin treatment.
At diagnosis of diabetes, absence of all islet autoantibodies and modest hyperglycemia should indicate DNA sequencing for MODY. Testing all 12% patients who are negative for four islet autoantibodies may be a more effective strategy for not missing MODY. Patients with MODY have excellent long-term glycemic control even without insulin and therefore it mandatory to identify these patients in all countries.