Weight-gain induced changes in renal perfusion assessed by contrast-enhanced ultrasound precede increases in urinary protein excretion suggestive of glomerular and tubular injury and normalize after weight-loss in dogs

PLoS One. 2020 Apr 21;15(4):e0231662. doi: 10.1371/journal.pone.0231662. eCollection 2020.

Abstract

Early detection of obesity-related glomerulopathy in humans is challenging as it might not be detected by routine biomarkers of kidney function. This study's aim was to use novel kidney biomarkers and contrast-enhanced ultrasound (CEUS) to evaluate the effect of obesity development and weight-loss on kidney function, perfusion, and injury in dogs. Sixteen healthy lean adult beagles were assigned randomly but age-matched to a control group (CG) (n = 8) fed to maintain a lean body weight (BW) for 83 weeks; or to a weight-change group (WCG) (n = 8) fed the same diet to induce obesity (week 0-47), to maintain stable obese weight (week 47-56) and to lose BW (week 56-83). At 8 time points, values of systolic blood pressure (sBP); serum creatinine (sCr); blood urea nitrogen (BUN); serum cystatin C (sCysC); urine protein-to-creatinine ratio (UPC); and urinary biomarkers of glomerular and tubular injury were measured. Glomerular filtration rate (GFR) and renal perfusion using CEUS were assayed (except for week 68). For CEUS, intensity- and time-related parameters representing blood volume and velocity were derived from imaging data, respectively. At 12-22% weight-gain, cortical time-to-peak, representing blood velocity, was shorter in the WCG vs. the CG. After 37% weight-gain, sCysC, UPC, glomerular and tubular biomarkers of injury, urinary immunoglobulin G and urinary neutrophil gelatinase-associated lipocalin, respectively, were higher in the WCG. sBP, sCr, BUN and GFR were not significantly different. After 23% weight-loss, all alterations were attenuated. Early weight-gain in dogs induced renal perfusion changes measured with CEUS, without hyperfiltration, preceding increased urinary protein excretion with potential glomerular and tubular injury. The combined use of routine biomarkers of kidney function, CEUS and site-specific urinary biomarkers might be valuable in assessing kidney health of individuals at risk for obesity-related glomerulopathy in a non-invasive manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / urine
  • Blood Urea Nitrogen
  • Contrast Media / pharmacology
  • Creatinine / blood
  • Disease Models, Animal
  • Dogs
  • Glomerular Filtration Rate
  • Glomerulonephritis / etiology
  • Glomerulonephritis / metabolism*
  • Glomerulonephritis / pathology
  • Glomerulonephritis / urine
  • Humans
  • Kidney Glomerulus / diagnostic imaging
  • Kidney Glomerulus / injuries
  • Kidney Glomerulus / metabolism*
  • Kidney Glomerulus / pathology
  • Kidney Tubules / diagnostic imaging
  • Kidney Tubules / injuries
  • Kidney Tubules / metabolism*
  • Kidney Tubules / pathology
  • Obesity / complications
  • Obesity / diagnostic imaging
  • Obesity / metabolism*
  • Obesity / pathology
  • Ultrasonography
  • Urinary Tract / metabolism
  • Urinary Tract / pathology
  • Weight Gain / genetics*
  • Weight Gain / physiology
  • Weight Loss / genetics
  • Weight Loss / physiology

Substances

  • Biomarkers
  • Contrast Media
  • Creatinine

Grants and funding

This work was funded by the Special Research Fund of Ghent University, Belgium (BOF grant 01N02215). Virbac financially supported blood and urine analyses and the diet used in the study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.