Serum levels of adipokine retinol-binding protein-4 in relation to renal function.
OBJECTIVE
Retinol-binding protein (RBP)-4 was recently identified as an adipokine that induces insulin resistance. In the current study, we investigated RBP-4 serum levels in diabetic and nondiabetic patients on chronic hemodialysis (CD) compared with control subjects with a glomerular filtration rate >50 ml/min. The majority of the diabetic subjects used oral hypoglycemic agents or insulin.


METHODS
RBP-4 was determined by enzyme-linked immunosorbent assay in control subjects (n = 59) and CD patients (n = 58) and correlated with clinical and biochemical measures of renal function, glucose and lipid metabolism, and inflammation in both groups.


RESULTS
Mean serum RBP-4 levels were almost fourfold higher in CD patients (102 +/- 30 mg/l) compared with control subjects (28 +/- 8 mg/l). Furthermore, serum creatinine independently predicted RBP-4 concentrations in multiple regression analyses in both control subjects and CD patients. In addition, C-reactive protein and systolic blood pressure independently and negatively correlated with RBP-4 serum concentrations in CD patients but not control subjects. In contrast, markers of glucose and lipid metabolism were not independently related to serum RBP-4 in control subjects or CD patients.


CONCLUSIONS
We show that markers of renal function are independently related to serum RBP-4 levels.
Ziegelmeier
Michaela
M
Department of Internal Medicine III, University of Leipzig, Leipzig, Germany.
Bachmann
Anette
A
Seeger
Jeannette
J
Lossner
Ulrike
U
Kratzsch
Jürgen
J
Blüher
Matthias
M
Stumvoll
Michael
M
Fasshauer
Mathias
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007676:Kidney Failure, Chronic / Q000097:blood*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012044:Regression Analysis; D006435:Renal Dialysis; D012177:Retinol-Binding Proteins / Q000378:metabolism*; D054839:Retinol-Binding Proteins, Plasma; D044465:White People
D015415:Biomarkers; D007328:Insulin; C101326:RBP4 protein, human; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma