Platelet Indices and Adipokines in Adults with Long‐Standing Type 1 Diabetes

Background: Type 1 diabetes mellitus (T1D) is associated with chronic inflammation, platelet activation, and increased cardiovascular risk (CVR). The relationships between adipokines and platelet indices in long-standing T1D remain incompletely defined. Objective: To explore the relationships between adipokines (adiponectin and leptin), platelet indices, and inflammatory status in adults with long-standing T1D. Methods: This cross-sectional study included 124 adults with long-standing T1D and 59 non-diabetic controls. Platelet indices were obtained from automated blood count, and serum leptin (LEP), adiponectin (ADNC), and C-reactive protein (CRP) were measured using standardized assays. Associations were evaluated using correlation and multivariable regression analyses with adjustment for body mass index (BMI). Results: Platelet count (PLT) and plateletcrit (PCT) were higher in T1D compared with non-diabetic individuals (p=0.003 for both), while mean platelet volume (MPV) and platelet distribution width (PDW) showed non-significant upward trends. ADNC levels were higher in T1D (p< 0.001), whereas LEP and the leptin–adiponectin ratio (LAR) did not differ between groups. In T1D, LEP correlated with PLT (rho=0.235), PCT (rho=0.263), and CRP (rho=0.474), all p< 0.05. Similar associations were observed for LAR. No significant associations were found in non-diabetic controls. In multivariable analyses, PCT remained associated with LEP in T1D after adjustment for BMI, whereas in the control group LEP was associated with BMI only. Conclusion: LEP and platelet-related indices were associated in individuals with long-standing T1D, whereas ADNC showed no such relationships. These findings suggest a distinct pattern of adipokine–platelet associations in long-standing T1D.