Hyperglycemia metrics from continuous glucose monitoring are independently associated with platelet morphology in adults with type 1 diabetes

INTRODUCTION: Platelet morphology indices are indirectly related to platelet reactivity and may link glycemic exposure to cardiovascular risk. OBJECTIVES: We aimed to investigate associations between continuous glucose monitoring (CGM)-derived metrics and platelet morphology in adults with T1DM. PATIENTS AND METHODS: In this cross-sectional study, we enrolled adults with T1DM without established cardiovascular disease. Platelet morphology indices were measured from fasting blood samples using the Sysmex XN-1000 analyzer within 2 hours of blood collection. Glucose profiles were assessed using CGM over 7-, 14-, and 30-day windows and calculated with Glyculator 3.0. We used Spearman correlation and multivariable linear regression models adjusted for age, sex, BMI, diabetes duration, C-reactive protein, glomerular filtration rate, HbA1c, smoking, and platelet count. RESULTS: We included 301 adults with T1DM [median age 33.1 (24.1-41.0), 44.5% men, diabetes duration 13 (7-19) years]. Platelet large cell ratio (P-LCR), mean platelet volume (MPV), and platelet distribution width (PDW)correlated positively with mean glucose (R = 0.27-0.30), time above range (TAR) level 2 (P = 0.25-0.29), glycemic risk index (R = 0.28-0.30), and mean amplitude of glucose excursion (MAGE) (R = 0.20-0.22), and inversely with time in range (R = -0.25 to -0.30; all P < 0.001), but not with hypoglycemia indices. In multivariable models, hyperglycemia-related metrics remained independently associated with P-LCR (standardized β 1.37-1.59; ΔR² 0.014-0.024; P = 0.002); MAGE lost significance in the multivariable model after accounting for TAR level 2. CONCLUSION: In adults with T1DM, platelet morphology independently relates to cumulative hyperglycemic exposure rather than glycemic variability or hypoglycemia.