Endocrine Abstracts

Heterogeneity of diabetes mellitus (DM) determines difficulties in the diabetes type verification and further treatment. With this regard, in 2019 WHO published a new classification of DM with categories: “hybrid types of diabetes” and “unclassified diabetes” intended for use in clinical practice.

Aim: To investigate the heterogeneity and clinical features of DM in young adult patients with an unspecified type of diabetes.

Materials and methods: 50 young adult people ± 33.2 years (18–45 years) with an unspecified type of DM were included. All patients underwent a genetic testing for GCK, HNF1α and HNF4α genes mutations for MODY diagnosis. In all included patients we analyzed levels of GADA, IA-2A, ICA, IIA, ZnT8 antibodies and C-peptide levels during oral glucose tolerance test. Type 2 DM (T2DM) was established in patients no mutations and absence of β-cell antibodies.

Results: MODY2 was diagnosed in 46.94% of patients, MODY3 −12.24%, MODY1 −2.04%, T2DM −28.57%, LADA −2.04%, T1DM - 10.2%. MODY1 and LADA were established for only 2 patients and were not included in the statistical analysis. Debut of carbohydrate metabolism disorders in MODY2 and T1DM were diagnosed earlier than in other types of DM: 23 years [9; 41] and 25.4 years [18; 25] vs 30.5 years [10; 42] in MODY3 and 31.5 years [18; 45] in T2DM, (P <0.05). Median of HbA1c level did not differ between groups: in MODY2 6.4% [5.0; 10.3], MODY3 −6.65% [5.6; 11.8], T2DM −6.55% [5.2; 12.6], T1DM −7.2% [6.4; 7.5], (P > 0.05). BMI did not differ between groups: MODY2 −20.6 kg/m² [15.6; 35.1], MODY3 -24.1 kg/m² [20.2; 29.3], T2DM −23.1 kg/m² [18.5; 36.1], T1DM −22.25 kg/m² [20.4; 23.0], (P > 0.05). Significant differences were observed in C-peptide secretion levels: the lowest levels were observed in patients with T2DM (0 min −1.29 ng/ml [0.64; 3.91], 60 min −6.7 ng/ml [5.6; 12.2], 120 min −4.45 ng/ml [3.1; 10.21]) compared with patients with other groups (MODY2, MODY3), (P <0.05).

Conclusion: The study demonstrates the significant clinical heterogeneity of DM in the young age group. Genetic and immunological tests are necessary to verify monogenic and autoimmune forms of DM and also important for determining further management. Young patients with T2DM require further studies, in order to identify underlying mechanisms of impaired insulin secretion.