Abstract
Background/Objectives: Diabetes mellitus (DM) is a major global health concern, yet limited research has examined how sociodemographic factors and physical activity (PA) influence glycaemic control within specific national contexts. This pilot study explored associations between sociodemographic and behavioral factors and glycaemic regulation among adults with DM in Croatia. Methods: A cross-sectional study was conducted at a national reference center, including 95 adults with type 1 or type 2 diabetes. Data on demographics, clinical characteristics, and PA were obtained through questionnaires and medical records. Descriptive statistics, Welch's t-tests, χ(2) tests, correlations, and regression analyses were applied to identify predictors of HbA1c and diabetes-related complications. Glycaemic control was categorized as optimal (HbA1c ≤ 7.5%) or suboptimal (>7.5%) according to the pragmatic clinical threshold commonly used in DM management. Results: Mean HbA1c was 6.9% (SD = 1.3), with 33.7% of participants above 7.5%. Higher education (β = -0.48, p = 0.013) and participation in strength or balance exercises (β = -0.32, p = 0.041) were associated with lower HbA1c, whereas longer disease duration (β = 0.03, p = 0.004) and type 2 diabetes (β = 0.38, p = 0.030) predicted higher HbA1c. In logistic regression, age predicted cardiovascular comorbidities (OR = 1.12, 95% CI 1.02-1.23, p = 0.019). The interaction between PA and place of residence (urban vs. rural) showed a non-significant trend (p = 0.061). Conclusions: Glycaemic control in Croatian adults with diabetes was associated with educational level and engagement in strength and balance exercises, while longer disease duration, older age, and type 2 diabetes were linked to poorer regulation and more complications. These findings underscore the importance of structured exercise and patient education in diabetes management, although larger, prospective studies with standardized PA-intensity measures are required to confirm and extend these results.