Abstract Background Type 1 diabetes mellitus has become a global health burden, and poor glycemic control, in combination with prolonged diabetes duration, leads to the early development of microvascular complications, including diabetic kidney disease, retinopathy, and neuropathy. Therefore, it is urgent to establish new biomarkers for the early identification of at-risk patients. Objectives To investigate the role of inflammatory proteins (human growth differentiation factor 15 and interleukin 29) in the course of microvascular complications and glycemic control in T1DM. Patients and Methods Our study included 40 children with T1DM (18 T1DM patients had microvascular complications and 22 T1DM patients were free of these complications; their ages ranged from 8 to 18 years); there was also another T1DM subgroup based on glycemic control (11 T1DM patients had controlled HbA1c < 7% and 29 patients had uncontrolled HbA1C > 7%). 40 children of the same age were selected as a control group. The diagnosis of TIDM was made based on the criteria of the International Society of Pediatric and Adolescent Diabetes (ISPAD) (2022). A detailed medical history was collected, including the age of onset of diabetes, disease duration, and symptoms of diabetic complications. In the study, GDF15 and IL29 values in serum blood were investigated using the ELISA method. Results The mean age was 14.05 years in the diabetic group and 13.25 years in the control group (P = 0.178). In the T1DM patient group, the GDF15 and IL29 values were found to be significantly higher than those in the control group (P = 0.041 and 0.013, respectively). In diabetic patients, GDF15 was significantly higher in the complicated T1DM group versus the uncomplicated group (P = 0.001). Furthermore, GDF15 levels were significantly higher in uncontrolled patients with HbA1C > 7% than in the control group with HbA1C < 7% (P = 0.004); however, no significant statistical differences in IL29 levels were found between diabetic patient subgroups (P > 0.05). Conclusion The data from this study showed that GDF15 has an impact on glycemic control and that the presence of microvascular complications in the course of T1DM is very possible, but IL29 does not appear to play a role in the course of microvascular complications.