Urinary fatty acids and liver-type fatty acid binding protein in diabetic nephropathy.
BACKGROUND
The aims of this clinical study were to investigate the associations of urinary free fatty acid (FFA) levels with tubulointerstitial damage, and to determine the clinical significance of urinary liver-type fatty acid binding protein (L-FABP) in diabetic nephropathy.


METHODS
Fifteen patients with nephrotic syndrome due to diabetic nephropathy and 12 patients with minimal-change nephrotic syndrome (MCNS) were studied. Urinary and serum FFA concentrations (palmitic, oleic, linoleic, and arachidonic acids) were measured by gas chromatography, and urinary L-FABP levels were quantified using an ELISA technique. Tubulointerstitial damage was assessed using renal biopsy specimens.


RESULTS
The levels of urinary linoleic and arachidonic acids were significantly elevated in diabetic nephropathy compared to MCNS patients, though serum FFA levels were lower in diabetic nephropathy than MCNS patients. The degree of tubulointerstitial damage was significantly severer in the patients with diabetic nephropathy than MCNS. Urinary L-FABP and 8-OHdG (8-hydroxydeoxyguanosine) concentrations were significantly higher in the diabetic nephropathy subjects.


CONCLUSIONS
Elevated urinary excretion of FFA may be a reflection of FFA overload in the proximal tubules, and FFA may be an important promoter of tubulointerstitial damage in diabetic nephropathy patients. Urinary L-FABP levels may reflect the stress induced by FFA to the proximal tubules, leading to severe tubulointerstitial damage.
Sasaki
Hiroyo
H
Department of Nephrology and Hypertension, Internal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan.
Kamijo-Ikemori
Atsuko
A
Sugaya
Takeshi
T
Yamashita
Kayoko
K
Yokoyama
Takeshi
T
Koike
Jyunki
J
Sato
Takeo
T
Yasuda
Takashi
T
Kimura
Kenjiro
K
D000328:Adult; D015415:Biomarkers / Q000652:urine; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000652:urine*; D050556:Fatty Acid-Binding Proteins / Q000652:urine*; D005230:Fatty Acids, Nonesterified / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D015415:Biomarkers; C493319:FABP1 protein, human; D050556:Fatty Acid-Binding Proteins; D005230:Fatty Acids, Nonesterified