O39 IMPACT OF UROMODULIN CONCENTRATION ON RENAL AND HAEMODYNAMIC PARAMETERS IN A BLACK AFRICAN COMMUNITY WITH A HIGH PREVALENCE OF HYPERTENSION

Background and Objective: The burden of hypertension (HTN) and related comorbidities disproportionately affects developing countries like South Africa, particularly in urban populations of African ancestry. This demographic exhibits a volume-dependent form of HTN that is resistant to antihypertensive drugs that target the renin-angiotensin-aldosterone system. Renal fluid retention or abnormalities may cause HTN in this group, thus the need to investigate various nephron components for a better understanding. Uromodulin is a potential biomarker for renal function and tubular reserve. However, the relationship with renal function, haemodynamic parameters and HTN in a Black African population is unknown. Therefore, the aim of this study was to explore the relationship between urinary uromodulin concentration and renal as well as haemodynamic parameters in a Black African community with a high prevalence of volume-dependent HTN. Methods: Systemic haemodynamics (central pressures [SphygmoCor] and echocardiographic aortic velocity and diameter measurements in the outflow tract), urinary uromodulin concentrations (ELISA assay) and renal function (creatinine clearance from 24-hour urine collections [n=370]) were determined in a Black African community (n=397). Results: No relationships between urinary uromodulin concentrations and age, body mass index, blood pressure or hypertension were noted. However, urinary uromodulin concentrations were higher in females than males, even after adjusting for several confounders (p=0.0007). Although urinary uromodulin concentrations were unrelated to renal function, an inverse relationship with stroke volume (SV) was observed (p=0.0023). The inverse relationship between SV and urinary uromodulin concentration was independent of confounders and present in hypertensives (p=0.007) but not normotensives (p=0.43). The hypertensives were noted to have a higher SV than the normotensives (p=0.047). Conclusion: In a Black African community sample with a high prevalence of volume-dependent primary hypertension, urinary uromodulin was inversely related to SV, particularly in participants with hypertension. These data suggest the need to investigate the mechanisms linking urinary uromodulin to haemodynamic parameters to identify novel pathways to target for better treatment strategies in hypertension.