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Toxicity of Perirenal Fat in Overweight or Obese Subjects: A Pathophysiological Link Between Uric Acid Stones and Renal Ammonium Formation

Toxicity of Perirenal Fat in Overweight or Obese Subjects: A Pathophysiological Link Between Uric Acid Stones and Renal Ammonium Formation

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02561858
Enrollment
20
Registered
2015-09-28
Start date
2015-10-14
Completion date
2016-09-29
Last updated
2018-03-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Uric Acid Stones

Keywords

Renal Ammonium ;uric acid

Brief summary

Patients who are overweight or obese, diabetic or not, share with those who are suffering from uric stones the same way to remove abnormal acidity of the body in urine, ie a kidney ammoniogenesis default. This results in an overly acidic urine pH which is directly pathogenic in people predisposed to develop uric stones because the precipitation of urate soluble uric acid is accelerated in acid medium. Excess visceral fat, particularly perirenal, this defect may promote formation of renal ammonium. Indeed, the perirenal fat is adjacent to the renal cortex and shares with it a common arterial supply via the plexus Turner. Adipokines and fatty acids of the perirenal fat are predisposed to gain the renal cortex, seat of the ammoniogenesis. In humans the pathogenic role of the perirenal fat is demonstrated in chronic kidney disease and essential hypertension. However, the amount of fat and perirenal that of intra-abdominal fat are positively correlated. Investigators hypothesis is that the perirenal fat also exert a pathogenic role in uric because of anatomical links between kidney stones and greasy environment and because excess fatty acids reaching the renal cortex decreases ammoniogenesis in an animal model metabolic syndrome. For the test, the investigators will compare the amount of fat and perirenal renal ability to form ammonium in patients with uric or calcium lithiasis taking into account the amount of intra-abdominal fat.

Interventions

OTHERacid load test

Sponsors

Centre Hospitalier Universitaire de Nice
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

* Urolithiasis Uric defined by more than 90% of uric acid anhydrous and / or dihydrate or calcium lithiasis defined by more than 90% mono calcium oxalate and / or dihydrate, and / or carbapatite and / or brushite; * Overweight and obesity defined by 25 \<BMI \<35 kg / m2

Exclusion criteria

* staghorn lithiasis, stones struvite or cystine; * Primary hyperparathyroidism; * Hyperthyroidism; * Any form of calcium or uric lithiasis secondary; * Abnormal kidney structure (cysts, cortical thinning, kidney tumor);

Design outcomes

Primary

MeasureTime frameDescription
the perirenal fat thickness (left)baselineThis is the perirenal fat thickness measured between the left posterior wall of the kidney and the posterior wall of the abdominal cavity on a TDM section in the plane of the left renal vein.

Secondary

MeasureTime frameDescription
the perirenal fat thickness (right)baselinethe average thickness of perirenal fat measured to the right
NH4 + / NAEat day 7 of a standard dietIt is the ratio NH4 + / NAE measured over 24 hours of urine collected at day 7 of a standard diet; it determines from acid removed as ammonium whose production is regulated physiologically by the kidneys
net acid urinary flowat day 7 of a standard diet and when urine pH became <5.5This is the net acid urinary flow and report NH4 + / creat obtained when the urine pH became \<5.5, in an acidic filler.

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026