Association between serum retinol-binding protein 4 concentrations and clinical indices in subjects with type 2 diabetes: a meta-analysis.
BACKGROUND
Retinol-binding protein (RBP4) is an adipokine that may be important in type 2 diabetes. Previous studies have examined the association between serum RBP4 concentrations and clinical indices in patients with type 2 diabetes, although the results obtained have been inconsistent. We conducted a meta-analysis aiming to investigate the association between serum RBP4 concentrations and clinical indicators of diabetes, renal function, metabolic syndrome and obesity in subjects with type 2 diabetes.


METHODS
MEDLINE, EMBASE and CINAHL databases were searched from 2005 through November 2011, and the search identified 21 clinical variables from seven studies (total n = 1406). For each variable, summary correlation coefficients (r(s) ) were estimated using a random-effects meta-analysis.


RESULTS
None of the diabetes markers were correlated with serum RBP4 concentrations in subjects with type 2 diabetes, whereas all of the renal function markers and many metabolic syndrome markers were significantly correlated. Summary correlation coefficients and 95% confidence intervals (CIs) were -0.36 (95% CI = -0.51 to -0.18) for creatinine clearance, -0.39 (95% CI = -0.44 to -0.33) for estimated glomerular filtration rate and 0.53 (95% CI = 0.30-0.71) for creatinine concentration. In addition, plasma triglyceride concentrations (r(s) = 0.22; 95% CI = 0.11-0.32), plasma total cholesterol concentrations [r(s) = 0.14 (95% CI = 0.05-0.23)] and low-density lipoprotein cholesterol level (r(s) = 0.14; 95% CI = 0.02-0.25) were positively correlated with serum RBP4 concentrations.


CONCLUSIONS
The results obtained in the present study suggest that serum RBP4 concentrations in patients with type 2 diabetes may be associated with diabetes-related renal dysfunction and imbalances in lipid metabolism.
Department of Nutritional Sciences, College of Health and Human Development, Pennsylvania State University, University Park, PA, USA.
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H
Park
M H
MH
Green
M L
ML
Shaffer
D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000097:blood; D003404:Creatinine / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood; D016239:MEDLINE; D024821:Metabolic Syndrome / Q000097:blood; D009765:Obesity / Q000097:blood; D054839:Retinol-Binding Proteins, Plasma / Q000032:analysis*; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D008077:Lipoproteins, LDL; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma; D014280:Triglycerides; D002784:Cholesterol; D003404:Creatinine