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

Uric Acid Stones Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02561858
• Other study ID #: 15-AOI-07
• Status: Completed
• Phase: N/A
• First received: September 22, 2015
• Last updated: March 8, 2018
• Start date: October 14, 2015
• Est. completion date: September 29, 2016

Study information

• Verified date: March 2018
• Source: Centre Hospitalier Universitaire de Nice
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: September 29, 2016
• Est. primary completion date: June 24, 2016
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 18 Years to 70 Years

Eligibility

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);

Related Conditions & MeSH terms

• Nephrolithiasis
• Overweight
• Uric Acid Stones

Intervention

Other:
• acid load test

Locations

Country	Name	City	State
France	CHU de Nice	Nice

Sponsors (1)

Lead Sponsor	Collaborator
Centre Hospitalier Universitaire de Nice

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	the perirenal fat thickness (left)	This 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.	baseline
Secondary	the perirenal fat thickness (right)	the average thickness of perirenal fat measured to the right	baseline
Secondary	NH4 + / NAE	It 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	at day 7 of a standard diet
Secondary	net acid urinary flow	This is the net acid urinary flow and report NH4 + / creat obtained when the urine pH became <5.5, in an acidic filler.	at day 7 of a standard diet and when urine pH became <5.5