Increased urinary markers of kidney damage in the institutionalized frail elderly due to recurrent urinary tract infections

María-Fernanda Lorenzo-Gómez; María-Carmen Flores-Fraile; Magaly Márquez-Sánchez; Javier Flores-Fraile; Ignacio González-Casado; Bárbara Padilla-Fernández; Sebastián Valverde-Martínez; Teresa Hernández Sánchez; Carlos Muller-Arteaga; María-Begoña García-Cenador

doi:10.1177/1756287220974133

Increased urinary markers of kidney damage in the institutionalized frail elderly due to recurrent urinary tract infections

Ther Adv Urol. 2020 Dec 7:12:1756287220974133. doi: 10.1177/1756287220974133. eCollection 2020 Jan-Dec.

Affiliations

¹ Department of Surgery, University of Salamanca, Salamanca, Spain Multidisciplinary Renal Research Group) of the Institute for Biomedical Research of Salamanca (IBSAL), Spain Urology Service of the University Hospital of Salamanca, Salamanca, Spain.
² Department of Surgery, University of Salamanca, Salamanca, Spain.
³ Multidisciplinary Renal Research Group) of the Institute for Biomedical Research of Salamanca (IBSAL), Spain.
⁴ Department of Surgery, University of Salamanca, Alfonso X el sabio Campus Miguel de Unamuno, Salamanca, 37008, Spain.
⁵ Department of Surgery, Section of Urology, University La Laguna, Tenerife, Spain.
⁶ Department of Surgery, University of Salamanca, Salamanca, Spain Multidisciplinary Renal Research Group) of the Institute for Biomedical Research of Salamanca (IBSAL), Spain Department of Urology of University Hospital of Avila, Spain.
⁷ Urology Service of the University Hospital of Salamanca, Salamanca, Spain.
⁸ Department of Urology of University Hospital of Ourense, Spain.

Abstract

Objective: To characterize the impact on kidney injury of recurrent urinary tract infections (RUTI) in the frail elderly.

Methods: Prospective observational study in 200 frail elderly subjects for 1 year. Groups: GA (n = 100): subjects without RUTI, GB (n = 100): subjects with RUTI. Variables: age, concomitant diseases, glomerular filtration rate (GFR), urine neutrophil gelatinase-associated lipocalin (NGAL) at the beginning (NGAL-1) and end (NGAL-2) of the study, urine N-acetyl glucosaminidase (NAG) at the beginning (NAG-1) and the end (NAG-2) of the study, urine transforming growth factor-beta 1 (TGFβ-1). Descriptive statistics, Mann-Whitney test, Chi-squared test, Fisher's exact test, and multivariate analysis were used.

Results: Mean age was 84.33 (65-99) years old, with no difference between GA and GB. Mean NGAL-1 was 1.29 ng/ml (0.04-8). There was lower in GA than in GB. Mean NGAL-2 was 1.41 ng/ml (0.02-9.22). NGAL-2 was lower in GA than in GB. Mean NAG-1 was 0.38 UU.II/ml (0.01-2.63. NAG-1 in GA was lower than in GB. Mean NAG-2 was 0.44 UU.II/ml (0-3.41). NAG-2 was lower in GA compared with GB. Mean TGFβ-1 was 23.43 pg/ml (0.02-103.76). TGFβ-1 was lower in GA than GB. There were no differences in the presence of secondary diagnoses between GA and GB. NAG-2 and NGAL-1 were the most determining factors of renal function; in GA it was NGAL-2, followed by NAG-1; in GB it was NGAL-1, followed by NAG-2.

Conclusion: Frail elderly with RUTI have higher urinary levels of renal injury markers, specifically NGAL, NAG, and TGFβ-1, chronically in periods between urinary tract infection (UTI). Urinary markers of renal injury, specifically NGAL, NAG, and TGFβ-1, identify early deterioration of renal function, compared with serum creatinine, or albuminuria, in frail elderly with recurrent urinary infections.

Keywords: NAG; NGAL; RUTI; TFG-beta 1; elderly; glomerular filtration.