Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.
BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in o...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2013-01-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3783420?pdf=render |
| _version_ | 1831764800439320576 |
|---|---|
| author | Ana Tobar Yaacov Ori Sydney Benchetrit Gai Milo Michal Herman-Edelstein Boris Zingerman Netta Lev Uzi Gafter Avry Chagnac |
| author_facet | Ana Tobar Yaacov Ori Sydney Benchetrit Gai Milo Michal Herman-Edelstein Boris Zingerman Netta Lev Uzi Gafter Avry Chagnac |
| author_sort | Ana Tobar |
| collection | DOAJ |
| description | BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03). Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001), a 94% higher Bowman's space volume (P=0.003), a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02) and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01). The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity-related renal disease. |
| first_indexed | 2024-12-22T05:50:16Z |
| format | Article |
| id | doaj.art-0a4e947c865648179e00e05a754032cd |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-22T05:50:16Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-0a4e947c865648179e00e05a754032cd2022-12-21T18:36:53ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0189e7554710.1371/journal.pone.0075547Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.Ana TobarYaacov OriSydney BenchetritGai MiloMichal Herman-EdelsteinBoris ZingermanNetta LevUzi GafterAvry ChagnacBACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03). Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001), a 94% higher Bowman's space volume (P=0.003), a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02) and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01). The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity-related renal disease.http://europepmc.org/articles/PMC3783420?pdf=render |
| spellingShingle | Ana Tobar Yaacov Ori Sydney Benchetrit Gai Milo Michal Herman-Edelstein Boris Zingerman Netta Lev Uzi Gafter Avry Chagnac Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. PLoS ONE |
| title | Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. |
| title_full | Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. |
| title_fullStr | Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. |
| title_full_unstemmed | Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. |
| title_short | Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria. |
| title_sort | proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria |
| url | http://europepmc.org/articles/PMC3783420?pdf=render |
| work_keys_str_mv | AT anatobar proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT yaacovori proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT sydneybenchetrit proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT gaimilo proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT michalhermanedelstein proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT boriszingerman proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT nettalev proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT uzigafter proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria AT avrychagnac proximaltubularhypertrophyandenlargedglomerularandproximaltubularurinaryspaceinobesesubjectswithproteinuria |