Correlation between the prevalence of type 1 diabetes with the daily insulin dose and the autoimmune process against glutamic acid decarboxylase in adults

Abstract

In this study, we compared the rate of insulin requirement among adults with type 1 diabetes (T1D) in 24 Ukrainian regions. The glutamic acid decaroxylase 65 antibody (GADA), insulin antibody (IA), and plasma c-peptide levels were investigated. The data included the prevalent cases of T1D in Ukraine at the end of 2006. Only persons aged over 14 years at the time of inclusion into the Ukrainian register and diagnosed with diabetes before 30 years of age were included in this study ( n = 26 796). A total of 86 T1D patients (42 males; 44 females) with a mean age of 27.5 years (0.86) and a mean diabetes duration of 10.3 (0.72) years (SE), were randomly selected from four regional diabetes registers. The GADA, IA, and the plasma c-peptide levels were also determined. The logistic regression model was used, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. Furthermore, the differences in the T1D prevalence among the 24 Ukrainian regions were obtained ( p < 0.001). In the “minimal” regional cluster (MIC), the prevalence rate was 6 (5–6), and in the “maximal” (MAC) regional cluster, it was − 9 (8–9) per 10 000 adults. For patients with a disease duration (DD) of up to 15 years ( n = 13 677), the daily insulin dose (DID) was observed to increase linearly with DD ( R = 0.899, p < 0.001). The median insulin doses were standardized according to DD, and the values were lowest in the MIC and highest in the MAC populations: 45.89 (45.28–47.19) and 56.59 (53.33–57.88) U/24 h, respectively ( p < 0.01). Furthermore, the level of HbA1c in the MAC of T1D patients was observed to be higher than that in the MIC (9.52 ± 2.24%, n = 240, and 8.57 ± 3.29%, n = 111, respectively; p < 0.01). In addition, the GADA levels and persistence in the MAC patients ( n = 38) were higher than that in the MIC patients ( n = 48): 14.1 ± 4.6 and 3.2 ± 1.2 U/ml, respectively, mean ± SE; p = 0.028; OR = 9.66 (3.31–28.17), p < 0.001. Adjusting for age, gender, and duration of diabetes affected the results only slightly. Furthermore, the IA and c-peptide levels and their persistence were not observed to be associated with TD1 prevalence.