Circulating retinol-binding protein 4 and metabolic syndrome in the elderly

Abstract

RBP4 plays a role in biological mechanisms that are responsible for insulin resistance and development of type 2 diabetes.

Transgenic Mice Overexpressing Serum Retinol-Binding Protein Develop Progressive Retinal Degeneration through a Retinoid-Independent Mechanism

“…Therefore, there is a rather broad definition of normal/ healthy serum RBP4 levels, which range from 10 to 50 g/ml, depending on the methodology used in a specific study. Likewise, the relative increase in the serum RBP4 level associated with various disease states, such as obesity, insulin resistance, cardiovascular disease, and type 2 diabetes, can range from 17 to 150 g/ml (8,9,(11)(12)(13)(14)(15)(16)(17)(64)(65)(66)(67). In one particular study (11), about half of the patient samples in which RBP4 levels were measured had serum RBP4 levels above 100 g/ml, which is similar to the serum RBP4 level in young RBP4-Tg mice (Fig.…”

“…However, in the past decade numerous clinical studies have linked increased serum levels of RBP4 to disease, including obesity (8,9), insulin resistance (8)(9)(10)(11)(12)(13), type 2 diabetes (9, 13), and cardiovascular disease (hypertension, atherosclerosis, stroke) (14)(15)(16)(17)(18)). This appears to be more than a spurious correlation, since recent studies have demonstrated that RBP4 is an adipokine (adipose-derived cytokine) with retinoid-independent, proinflammatory activity that contributes to the development of insulin resistance (13,(19)(20)(21).…”

Retinol-Binding Protein 4 Induces Inflammation in Human Endothelial Cells by an NADPH Oxidase- and Nuclear Factor Kappa B-Dependent and Retinol-Independent Mechanism

“…levated levels of serum retinol-binding protein 4 (RBP4), the transport protein for vitamin A (retinol) in the blood circulation, correlate with insulin resistance and type 2 diabetes in several clinical studies (1,13,25,32,41,49,52,68). Furthermore, studies in mice have shown that ectopic overexpression of serum RBP4 inhibits insulin signaling in muscle and adipose tissues and causes systemic insulin resistance, whereas Rbp4 Ϫ/Ϫ mice have increased insulin sensitivity (8,68).…”

Early second trimester retinol‐binding protein‐4 values in cases with or without gestational diabetes mellitus risk factors: A cross‐sectional study

“…These actions of RBP‐4 have been proposed to result from IR . RBP‐4 levels have been related with not only IR but also metabolic syndrome, type 2 diabetes mellitus, obesity and dyslipidemia …”

“…11,20,21 RBP-4 levels have been related with not only IR but also metabolic syndrome, type 2 diabetes mellitus, obesity and dyslipidemia. 11,12,22 Pregnancy is a diabetogenic condition and RBP-4 values continue to rise during gestations of nondiabetic women, generally returning to normal range after delivery. 8 On the contrary, Inoue et al reported that the RBP-4 values were higher in the first trimester and decrease through the second trimester and plateau thereafter in normal pregnancies.…”