BACKGROUND The cytokine IL-17A is emerging as a marker of chronic inflammation in cardio-metabolic conditions. This study aimed to identify relevant factors that in older primary care patients with type 2 diabetes (T2D) could influence serum IL-17A concentrations. The results have a potential to improve risk stratification and therapy options for these patients. MATERIAL AND METHODS The study was conducted during a period of 4 months, in 2020, in the south-eastern region of Croatia. Patients from primary health care, diagnosed with T2D (N=170, M: F 75: 95, ≥50 years old), were recruited at their visits. Those with malignant diseases, on chemotherapy or biological therapy, with amputated legs, or at hemodialysis, were excluded. The multinomial regression models were used to determine independent associations of the groups of variables, indicating sociodemographic and clinical characteristics of these patients, with increasing values (quartiles) of serum IL-17A. RESULTS The regression models indicated the frailty index and sex bias are the key modifying factors in associations of other variables with IL-17A serum values. CONCLUSIONS Sex bias and the existence of different frailty phenotypes could be the essential determining factors of the serum IL-17A levels in community-dwelling patients with T2D age 50 years and older. The results support the concept of T2D as a complex disorder.