(P32-08-26) BMI and Diet Quality Relate to Platelet Activation and Reactivity in Children

Objectives: Platelets (PL) play a significant role in thrombosis and atherogenesis. Little is known about how PL reactivity relates to cardiovascular risk and diet quality in children. The objective of this secondary analysis was to examine associations between PL reactivity, cardiometabolic markers, diet quality, and physical fitness in participants from the MI-Energy study.

Methods: Children (n=68; 8–10 years) without major medical or psychiatric conditions completed a single fasted study visit at the Arkansas Children’s Nutrition Center. Age- and sex-specific BMI z-scores and blood pressure percentiles were calculated, fasting lipids, hs-CRP, insulin, and glucose were measured, and HOMA-IR estimated. Physical activity was assessed by accelerometry and fitness by VO₂peak during an incremental cycle test. Diet quality was evaluated using total and component Healthy Eating Index (HEI) scores. PL reactivity was assessed using a dose-response thrombin stimulation protocol with P-selectin quantified by flow cytometry at baseline (before thrombin stimulation) and at 1, 5, 10, and 25 minutes after stimulation. Associations were examined using linear mixed models adjusted for age, sex, and BMI percentile with Tukey correction.

Results: Children (9.4±0.8 years; 57% boys; 69% White) had a mean BMI z-score of 0.99±0.87 and a mean HEI score of 54.3±9.4. At baseline, P-selectin expression positively associated with BMI z-scores (β=2.2, p=0.023). P-selectin expression increased across the thrombin protocol (p < 0.0001). Adherence to refined grains (F(1, 68) = 12.73, p=0.0007) and greens and beans (F(1, 68) = 5.19, p=0.0258) recommendations, respectively, was associated with PL reactivity, with significant time-by-HEI score interactions for refined grains (F(3, 204) = 6.00, p=0.0006) and greens and beans (F(3, 204) = 3.42, p=0.0183), such that greater adherence was associated with lower P-selectin expression throughout the protocol.

Conclusions: PL P-selectin expression increased with increasing BMI-z score. Closer adherence to refined grain and greens and beans recommendations was associated with lower P-selectin expression across the stimulation protocol, independent of age, sex, and BMI. Further studies are needed to determine the underlying mechanisms, and clinical relevance of these associations.

Funding Sources: USDA-ARS 6026-10700-001-000D.