MO393: Kidney Echogenicity and Kidney Length as Surrogate Markers of Kidney Function With an Increased Echogenic Pattern Being the Most Predictive of Renal Dysfunction, Particularly in HIV
Authors: Frank Astley , Assounga Alain 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Non-communicable diseases (NCDs) are rapidly emerging as a major cause of chronic kidney disease (CKD) in Africa with a reported prevalence of 10.7% locally. At current, few high-quality studies assessing the epidemiology of CKD in South Africa have been published. Alarmingly, CKD is now at epidemic proportions and is a leading cause of mortality with significant cost implications. This study aims to investigate economic means of predicting renal function in CKD by exploring the association between estimated glomerular filtration rate (eGFR) and renal morphology evaluated by ultrasound (US).

METHOD
This is a retrospective descriptive chart review conducted at the Department of Nephrology, Inkosi Albert Luthuli Central Hospital (IALCH), Cato Manor, Kwa-Zulu Natal from January 2016 to December 2016. A total of 455 patients who had met the Kidney Disease Improving Global Outcomes (KDIGO) definition of CKD with eGFR (MDRD) and kidney US performed were included. Demographic, clinical, laboratory and kidney morphological data [kidney length (KL), increased echogenicity (IE) and loss of corticomedullary differentiation (LCMD)] on US were collected and analyzed with SPSS software (v. 27). Associations between eGFR, parameters on US and CKD risk factors were determined using logistic regression analysis.

RESULTS
Black Africans (75.2%; n = 342) and females (56.9%; n = 259) predominated the sample. Whilst, Indians, Whites and Coloreds comprised of 20.4%, 2.42% and 1.98% of the study respectively. The median age was 45.8 ± 14.3 years. Hypertension (34.9%), diabetes (26.8%), HIV (27.5%) and glomerulonephritis 9.89% were the four most frequently reported risk factors, of which Black Africans comprised more than 50% of cases (P &lt; 0.001). A significant proportion of patients 65.7% (n = 307) had end-stage renal disease with a median eGFR of 14.4 ± 12.8mL/min/1.73m2 (P &lt; 0.001). The median right and left KL were short at 8.49 ± 2.16 cm and 8.60 ± 2.20 cm respectively. Black Africans were also found to have significantly shorter KLs and lower eGFRs (P &lt; 0.001). The dual effect of IE and LCMD predisposed to significantly shorter KLs and lower eGFRs than in the presence of one or no abnormality on US (P &lt; 0.001). IE [−9.29 odds ratio (OR); 95% confidence interval (CI) (−13.8 to −4.77); P &lt; 0.001] and KL [right: 5.02 OR; 95% CI (3.44–6.60); P = 0.04; left: 5.11 OR; 95% CI (3.56–6.66); P = 0.04] were found to be significant predictors of eGFR. HIV was the only risk factor found to be negatively associated with all determined measures of renal function, as well as the sole predictor of IE [2.31 OR; 95% CI (0.17–3.15); P = 0.02].

CONCLUSION
The CKD epidemic is driven by the complex interplay between communicable (HIV) and NCDs (HPT/DM) and has emerged as important public health and economic threat in Southern Africa. Africans are most vulnerable presenting with an advanced and accelerated disease course. GFR determination and US are inexpensive means of determining renal function, particularly in resource-limited settings. IE and KL are surrogate markers of kidney function with an increased echogenic pattern being most predictive of kidney dysfunction in CKD, particularly in HIV.