Haemodynamic changes and peripheral vascular characteristics associated with pathophysiological alterations in Preeclampsia patients at the University Teaching Hospital, Lusaka, Zambia

Abstract

Background: The circadian blood pressure changes in pregnancy are poorly documented though the severity of hypertensive  disorders especially in pregnancy is said to be better detected by 24hour blood pressure monitoring. The contribution of peripheral vascular variations to these alterations is yet to be elicited. The association of these changes to the renal pathological dysfunction is also not fully understood.
Materials and method: Ambulatory blood pressure measurements and kidney function tests (i.e. creatinine, protein, sodium and uric acid) were done in patients admitted to UTH for hypertension in second and third trimesters of pregnancy. The Complior was used to determine the pulse waveform, pulse wave velocity (PWV) and augmentation index (Aix) as surrogate parameters for peripheral vascular compliance.
Results: Twenty-six (26) women, between 22-42 years old and 24-36 gestational weeks, participated in this study. The majority of our population were either non- or reverse dippers (91.6%). The type A pulse waveform was dominant in all three groups indicating endothelial dysfunction. Dippers had a higher creatinine concentration in both urine and serum and uric acid in serum than non-dippers (7.051mmol/24hrs; 108.703ìmol/L;0.507mmol/L; respectively p<0.0001). The observed association of diurnal variations in
hemodynamic parameters and dipping status indicates significant vascular pathology that may herald these individuals' increased risk of cardiovascular complications. The dominance of the type A pulse waveform in this population is indicative of significant endothelial dysfunction.
Conclusion: The association seen between elevated blood pressure readings and proteinuria indicates a possible common pathophysiological process that leads to increased porosity at the glomeruli. 

Keywords: Diurnal blood pressures, preeclampsia, arterial stiffness, pulse wave velocity