Non-invasive detection of endothelial dysfunction in sickle cell disease by Doppler ultrasonography.

OBJECTIVE: The purpose of the study was to assess endothelial function in sickle cell disease (SCD), to compare endothelial dysfunction between sickle cell anemia (SS) and sickle cell trait (SA) cases and to evaluate correlation of endothelial dysfunction with duration of symptoms and vaso-occlusive crises per year (voc/year) [severity of disease]. METHODS: We investigated 37 steady state SCD cases, of which 19 were SS [mean age = 23.15 + 5.27 years and M/F = 10/9] and 18 were SA cases [Mean age = 22.05 +/- 5.17 years and M/F = 9/9]. Age, sex, and hemoglobin matched 33 controls [15 (Hb < or = 11g%) for SS cases and 18 (Hb > or = 11g%) for SA cases] were studied. Endothelial function was assessed by flow-mediated dilation (FMD) in brachial artery by vascular Doppler after pneumatic tourniquet stress at forearm (by Celermajer DS, 1992). RESULTS: FMD was significantly impaired in SCD cases [6.22% + 0.91% in SS cases vs. 16.85% + 1.06% in controls, P<0.05 and 12.56% + 0.90% in SA cases vs. 16.99% + 1.05% in controls, P < 0.05]. Endothelial function was impaired more in SS as compared to SA cases (p < 0.05). Decline in endothelial function was observed with increasing duration of symptoms and voc/year in SS cases. CONCLUSION: These results suggest that endothelial function is impaired in SCD and endothelial function is impaired more in SS as compared to SA cases.