Elevated retinol-binding protein 4 levels are associated with metabolic syndrome in Chinese people.
BACKGROUND
High retinol-binding protein 4 (RBP4) is thought to be associated with insulin resistance in humans. However, evidence from large-scale populations about the relationship between RBP4 and metabolic diseases is scarce.


OBJECTIVE
We evaluated plasma RBP4 distribution and its association with metabolic syndrome (MetS) among middle-aged and older Chinese.


METHODS
We evaluated plasma RBP4 in a cross-sectional sample of 3289 Chinese aged from 50 to 70 yr in Beijing and Shanghai by using an in-house developed and validated sandwich ELISA. MetS was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian-Americans.


RESULTS
RBP4 levels were higher in male and Beijing residents, compared with female and Shanghai participants (both P < 0.001). RBP4 levels were associated positively with body mass index, waist circumference, triglycerides, total and low-density lipoprotein cholesterol, blood pressure, fasting insulin, and homeostatic model assessment of insulin resistance and negatively with high-density lipoprotein cholesterol and adiponectin (all P < 0.001). In the highest RBP4 quartile, the MetS risk was significantly higher (odds ratio 2.58; 95% confidence interval 2.08-3.20) than in the lowest quartile after adjustment for potential confounders. This association remained strong (odds ratio 2.25; 95% confidence interval 1.72-2.94) after further controlling for C-reactive protein, adiponectin, homeostatic model assessment of insulin resistance, and body mass index.


CONCLUSIONS
This first large-scale population study shows that elevated RBP4 levels are strongly and independently associated with MetS. Prospective studies are needed to establish the role of RBP4 in the development of MetS and related diseases.
Qi
Qibin
Q
Key Laboratory of Systems Biology, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China.
Yu
Zhijie
Z
Ye
Xingwang
X
Zhao
Feng
F
Huang
Ping
P
Hu
Frank B
FB
Franco
Oscar H
OH
Wang
Jing
J
Li
Huaixing
H
Liu
Yong
Y
Lin
Xu
X
D052242:Adiponectin / Q000097:blood; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000453:epidemiology; D007333:Insulin Resistance / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D008875:Middle Aged; D016017:Odds Ratio; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism*
D052242:Adiponectin; D001786:Blood Glucose; D008055:Lipids; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma