Estimation of Kidney injury molecule-1 and microalbuminuria levels in hypertensive patients at the University Teaching Hospital,Lusaka

Abstract

Context— Acute kidney injury (AKI) and chronic kidney disease (CKD) represent one of the important health problems with high morbidity and mortality in Zambia. Recognition of AKI allows prompt injury specific intervention that may avert permanent renal damage and progression of CKD to End Stage renal Disease (ESRD) can also be delayed with early diagnosis and intervention. Hypertension is a major public health problem and the most important cause of renal failure and dialysis all over the world. Kidney injury molecule-1 (KIM-1) and Microalbuminuria (MAU) have been shown to be important biomarkers of kidney injury. There is less data on the levels of KIM-1 and Microalbuminuria in hypertensive patients at the University Teaching Hospital (UTH). Aims— the aim of the study was to determine the levels of kidney injury molecule-1 and microalbuminuria in hypertensive participants at the UTH. Methods and Results— an analytical cross section study was undertaken at the UTH. 40 hypertensive participants and 40 non hypertensive participants were enrolled to the study; the renal function tests (serum creatinine, urea, electrolytes) were determined using Olympus AU480 chemistry analyser. Urinary KIM-1 and MAU concentrations were determined using ELISA kits. Our results showed that there was no difference in KIM-1 levels between hypertensive participants (2.817 ± 1.359ng/mL) and non hypertensive participants (3.286 ± 1.143ng/mL) with p =0.122. However, the hypertensive participants had higher MAU levels (130.809 ± 84.744 µg/mL) than non hypertensive participants (15.983 ± 20.442µg/mL), with p ˂ 0.001. KIM-1 showed a positive correlation with MAU in hypertensive participants with statistical significance (r = 0.326, p = 0.045). However KIM-1 showed a weak negative correlation with creatinine (r = -0.279, p = 0.09), whereas MAU was positively correlated with creatinine in hypertensive participants with statistical significance (r = 0.556, p = 0.001). Conclusion— there was no difference in KIM-1 levels between hypertensive participants and non hypertensive participants. Hypertensive participants had higher MAU concentration than non hypertensive participants. The positive correlation between MAU and Creatinine could indicate that they can both be used to detect kidney injury in hypertensive individuals. In Zambian setting creatinine and Microalbuminuria are still the biomarkers of choice for the diagnosis of kidney injury. However, Urinary KIM-1 could provide diagnostic and prognostic advantages by providing information on the reversibility of kidney injury following treatment.