Serum retinol binding protein 4 and nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus

doi:10.1016/j.diabres.2007.08.016

Diabetes Research and Clinical Practice

Volume 79, Issue 2, February 2008, Pages 185-190

https://doi.org/10.1016/j.diabres.2007.08.016 Get rights and content

Abstract

Retinol binding protein 4 (RBP4) is a protein secreted by adipocytes, and closely associated with insulin resistance. Whereas RBP4 is also mainly expressed in hepatocytes as the principal transport protein for retinol (vitamin A) in the circulation, and its pathophysiological role in liver remain unclear. The aim of this paper was to investigate the association between RBP4 and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). Serum RBP4 and adiponectin concentrations were measured by radioimmunoassay in 52 diabetic patients who had NAFLD and 50 sex- and age-matched diabetic patients without any clinical features of liver diseases who had normal liver ultrasonic appearance and normal liver function. Serum RBP4 levels were elevated in diabetic patients with NAFLD (32.0 ± 8.9 μg/ml vs. 41.3 ± 9.8 μg/ml, p < 0.001), while adiponectin decreased (17.4 ± 9.3 μg/ml vs. 13.8 ± 7.0 μg/ml, p = 0.032). Male diabetic patients had higher serum RBP4 concentration and lower serum adiponectin concentration than female diabetic patients (38.5 ± 9.9 μg/ml vs. 34.0 ± 10.7 μg/ml, p = 0.031 and 12.7 ± 5.7 μg/ml vs. 20.23 ± 9.8 μg/ml, p < 0.001, respectively). Multiple logistic regression analysis revealed RBP4 and triglyceride as independent association factors for NAFLD, while the association between serum adiponectin and NAFLD was not significant. Increasing concentrations of RBP4 were independently and significantly associated with NAFLD in diabetic patients. In multiple linear regression analysis, alanine aminotransferase, fasting serum insulin and adiponectin were independent factors for serum RBP4 level. The study demonstrates that retinol binding protein 4 might contribute to the pathogenesis of nonalcoholic fatty liver disease.

Introduction

Yang et al. have proven that retinol binding protein 4 (RBP4) is a protein secreted by adipocytes, and increased in insulin resistant states [1]. Elevated serum RBP4 levels impair postreceptor insulin signaling in muscle and induce the expression of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase in the liver, which lead to insulin resistance, while lowering the serum levels of RBP4 improves insulin resistance and glucose tolerance in mice with obesity [1]. Human studies suggest that serum RBP4 level might contribute to systemic insulin resistance and be associated with diabetes, dyslipidemia, and cardiovascular risk factors [2]. However, RBP4 is also a cytokine that is mainly expressed in hepatocytes as the principal transport protein for retinol (vitamin A) in the circulation, and the pathophysiological roles of serum RBP4 in liver diseases are largely unknown [3].

Insulin resistance is the pathophysiological denominator that links all the components of the metabolic syndrome and may have a major role in the development of nonalcoholic fatty liver disease (NAFLD) [4]. Meanwhile, insulin resistance plays a pivotal role in type 2 diabetes mellitus (T2DM) and glucose intolerance and indeed there is strong association between these disorders and liver disease, and up to 75% of diabetic patients have NAFLD [5], [6], [7]. Diabetic medications that have been shown to correct insulin resistance may prove to be beneficial in NAFLD treatments [8], [9]. Thus, based on the strong association between RBP4 and insulin resistance, we postulate that RBP4 might contribute to the pathogenesis of NAFLD.

To investigate the role of RBP4 in NAFLD, we measured serum RBP4 level as well as adiponectin in type 2 diabetic patients with or without NAFLD.

Section snippets

Subjects

From November 2003 to April 2005, subjects with Han ethnicity in China who consecutively visited the Diabetic Clinic of Shanghai No. 6 People's Hospital for endocrinological and metabolic disorders or physical checkup were studied. One hundred and two diabetic patients (61 men and 41 menopausal women) newly diagnosed, aged 53.3 ± 8.5, were recruited. The diagnosis of type 2 diabetes mellitus (T2DM) was based on the WHO criteria [10]. Patients presenting with symptoms suggestive of type 1

Statistical analysis

The data are shown as the mean ± S.D. All of the statistical analyses were performed by SPSS version 11.5 (Statistical Package for the Social Science, SPSS Inc., Chicago, IL). Each variable was examined for normal distribution and significantly skewed variables were log transformed. For descriptive purposes, mean values were presented on untransformed and unadjusted variables. Since the distribution of diastolic blood pressure, HbA1c, triglycerides, HDL-cholesterol, ALT and γGT values were

Results

The clinical characteristics of the subjects are shown in Table 1. A total of 52 diabetic patients with NAFLD and 50 sex- and age-matched diabetic patients without NAFLD were studied. Diabetic patients with NAFLD had higher BMI, triglyceride, fasting serum insulin, HOMA-IR, ALT, γGT, and uric acid than those of control patients. Serum RBP4 levels were found to be elevated in diabetic patients with NAFLD (32.0 ± 8.9 μg/ml vs. 41.3 ± 9.8 μg/ml, p < 0.001). In contrast, adiponectin decreased (17.4 ± 9.3

Discussion

Individuals with T2DM have increased prevalence of NAFLD [5], [6], [7]. In a population study of patients with T2DM, standardized mortality rates due to liver disease exceed that due to cardiovascular diseases [12]. We demonstrated that RBP4 serum level increased in diabetic patients with NAFLD or in a fully adjusted model. It inferred there was a causal relationship between RBP4 and NAFLD.

Insulin resistance leads to the accumulation of fat in hepatocytes by lipolysis and hyperinsulinemia and

Acknowledgements

We are grateful to all colleagues in Diabetic Clinic of Shanghai No. 6 People's Hospital for assistance in recruiting patients. This work was funded by National Natural Science Foundation of China Project (30670989), Chinese National 973 Project (2006CB503901), and the Foundation of Shanghai Science and Technology Development (012D002(1)).

References (31)

Q. Yang et al.
Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes
Nature
(2005)
T.E. Graham et al.
Retinol-binding protein 4 and insulin resistance in lean, obese, and diabetic subjects
N. Engl. J. Med.
(2006)
W.S. Blaner
Retinol-binding protein: the serum transport protein for vitamin A
Endocr. Rev.
(1989)
G. Marchesini et al.
Association of nonalcoholic fatty liver disease with insulin resistance
Am. J. Med.
(1999)
W. Creutzfeldt et al.
Liver diseases and diabetes mellitus
Prog. Liver Dis.
(1970)
S. Abraham et al.
Receiver operating characteristic analysis of glycogenated nuclei in liver biopsy specimens: quantitative evaluation of their relationship with diabetes and obesity
Hum. Pathol.
(1994)
A. Propst et al.
Prognosis in non-alcoholic steatohepatitis (Letter)
Gastroenterology
(1995)
C.H. Wang et al.
Safety and effectiveness of rosiglitazone in type 2 diabetes patients with nonalcoholic Fatty liver disease
J. Formos Med. Assoc.
(2006)
M. Tiikkainen et al.
Effects of rosiglitazone and metformin on liver fat content, hepatic insulin resistance, insulin clearance, and gene expression in adipose tissue in patients with type 2 diabetes
Diabetes
(2004)
K.G. Alberti et al.
Definition, diagnosis and classification of diabetes mellitus and its complications. 1: Diagnosis and classification of diabetes mellitus, provisional report of a WHO consultation
Diab. Med.
(1998)

D.R. Matthews et al.

Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man

Diabetologia

(1985)

R. De Marco et al.

Cause specific mortality in type 2 diabetes. The Verona Diabetes study

Diab. Care

(1999)

I.A. Leclercq et al.

CYP2E1 and CYP4A as microsomal catalysts of lipid peroxidase in murine nonalcoholic steatohepatitis

J. Clin. Invest.

(2000)

G. Leonarduzzi et al.

The lipid peroxidation end product 4-hydroxy-2,3-nonenal up regulates transformin growth factor B1 expression in the macrophage lineage: a link between oxidation injury and fibrosclerosis

FASEB J.

(1997)

P. Angulo

Mechanisms of disease. Nonalcoholic fatty liver disease

N. Engl. J. Med.

(2002)

Cited by (74)

Isotope-dilution liquid chromatography-tandem mass spectrometry for quantification of human retinol binding protein 4 in serum
2022, Analytical Biochemistry
Citation Excerpt :
Of interest, the varying level in plasma or serum RBP4 might reflect renal impairment in type2 diabetes mellitus patients [5–7]. In addition, RBP4 is a biomarker for a series of metabolism-related diseases, including obesity, cardiovascular diseases, nonalcoholic fatty liver disease, gestational diabetes mellitus and polycystic ovary syndrome [8–12]. Presently, immunological analysis (e.g., RIA and ELISA) is the most commonly adopted method enabling simple and rapid clinical detection of RBP4 [5,6,10].
Serum retinol binding protein 4 levels play critical roles in the early diagnosis and therapeutic monitoring of diabetic kidney disease. In this paper, an liquid chromatography-tandem mass spectrometry approach for the absolute quantification of serum RBP4 with high sensitivity and specificity was presented. Following series of procedures including denaturation, reduction, alkylation and trypsin digestion, the signature peptides of RBP4 were separated on the HPLC system by gradient elution. Quantitative analysis was achieved by a triple quadrupole mass spectrometer under multiple reaction monitoring in the positive ion (ESI+) mode. The calibration range was from 6.25 to 125 mg/L (R² > 0.993), the lower limit of quantification was 2.50 mg/L, and the lower limit of detection reached 0.0150 mg/L. In the study, the accuracy ranged from 94.6% to 107%, and the relative standard deviation of intra-assay and inter-assay imprecision was less than 5%. The method was demonstrated to realize sensitive and reliable absolute quantification of serum RBP4 conforming to guidelines for bioanalytical method validation.
Circulating retinol-binding protein 4 is associated with the development and regression of non-alcoholic fatty liver disease
2020, Diabetes and Metabolism
Retinol-binding protein 4 (RBP4), primarily secreted by liver and adipose tissue, has been linked with non-alcoholic fatty liver disease (NAFLD). However, investigations on the relationships between RBP4 and NAFLD have produced inconsistent results. Therefore, the association between serum RBP4 levels and the development or regression of NAFLD was prospectively investigated.
A total of 3389 Chinese adults, aged 40–75 years and followed-up for 3.09 years, were included and analyzed in the study. NAFLD was diagnosed by abdominal ultrasonography. Serum RBP4 levels were measured, and their relationship to NAFLD development and regression assessed.
Of the 1318 participants without NAFLD at baseline, 410 developed NAFLD after follow-up. Baseline RBP4 was positively associated with incident NAFLD: the fully adjusted odds ratio (OR) was 2.01 with a 95% confidence interval (CI) of 1.33–3.04 (P = 0.003 for trend). After follow-up, a significant increase in RBP4 levels was observed in participants who developed NAFLD. On the other hand, in 1382 subjects diagnosed with NAFLD at baseline, 339 experienced NAFLD regression after follow-up. Thus, baseline RBP4 was inversely associated with NAFLD regression: the fully adjusted OR was 0.52 with a 95% CI of 0.34–0.80 (P < 0.001 for trend). A significant decrease in RBP4 after follow-up was also noted in participants with NAFLD regression.
Serum RBP4 concentrations are associated with the development and regression of NAFLD, making them a potential novel preventative and therapeutic target in NAFLD management.
Vitamin A signaling and homeostasis in obesity, diabetes, and metabolic disorders
2019, Pharmacology and Therapeutics
Citation Excerpt :
Human observational studies exploring relationships between serum/plasma RBP4 and NAFLD occurrence are largely in agreement with the conclusion that serum/plasma RBP4 levels are elevated in patients with NAFLD. A representative sample of, but not all correlative studies, include ones involving patients with type II diabetes (Wu et al., 2008), obese children (Romanowska, Lebensztejn, Skia, Trasów, & Kaczmarski, 2011), healthy 6- to 12-year-old children (Huang & Yang, 2013), subjects diagnosed with NAFLD but not type II diabetes (Yan et al., 2013), obese and lean patients diagnosed with NAFLD (Zwolak, Szuster-Ciesielska, Daniluk, Semeniuk, & Dandefer-Szerszen, 2016), postmenopausal women diagnosed with NALFD (Cai et al., 2018) and a community-based cross-sectional study involving 2938 participants 40-70-year-olds (Chen et al., 2017). Each of these studies reported significantly elevated serum/plasma RBP4 concentrations for patients with NAFLD but provided little insight into possible cause/effect relationships.
Much evidence has accumulated in the literature over the last fifteen years that indicates vitamin A has a role in metabolic disease prevention and causation. This literature proposes that vitamin A can affect obesity development and the development of obesity-related diseases including insulin resistance, type 2 diabetes, hepatic steatosis and steatohepatitis, and cardiovascular disease. Retinoic acid, the transcriptionally active form of vitamin A, accounts for many of the reported associations. However, a number of proteins involved in vitamin A metabolism, including retinol-binding protein 4 (RBP4) and aldehyde dehydrogenase 1A1 (ALDH1A1, alternatively known as retinaldehyde dehydrogenase 1 or RALDH1), have also been identified as being associated with metabolic disease. Some of the reported effects of these vitamin A-related proteins are proposed to be independent of their roles in assuring normal retinoic acid homeostasis. This review will consider both human observational data as well as published data from molecular studies undertaken in rodent models and in cells in culture. The primary focus of the review will be on the effects that vitamin A per se and proteins involved in vitamin A metabolism have on adipocytes, adipose tissue biology, and adipose-related disease, as well as on early stage liver disease, including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH).
Irisin in patients with nonalcoholic fatty liver disease
2014, Metabolism: Clinical and Experimental
Irisin is a recently discovered myokine proposed to increase thermogenesis-related energy expenditure and improve metabolism. We aimed to comparatively evaluate serum irisin levels in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) vs. controls and study their association with disease severity.
Fifteen and 16 consecutively enrolled patients with biopsy-proven nonalcoholic simple steatosis (NAFL) and steatohepatitis (NASH), respectively, and 24 lean and 28 obese controls without NAFLD were recruited. Irisin, established adipokines and biochemical tests were measured.
Serum irisin levels were statistically different in obese controls (33.7 ± 2.7 ng/mL; p < 0.001) and patients with NAFL (30.5 ± 1.5 ng/mL; p < 0.001) and NASH (35.8 ± 1.9 ng/mL; p = 0.001) compared with lean controls (47.7 ± 2.0 ng/mL), but were similar among patients with NAFL, NASH and obese controls. This difference remained significant after adjustment for body mass index (or waist circumference), gender, age, insulin resistance (assessed by HOMA-IR or QUICKI), exercise and time since blood collection. Serum leptin and adiponectin, but not irisin, levels were independently from BMI correlated with insulin resistance and cardiometabolic factors. Serum irisin tended to be higher in patients with (36.7 ± 2.4 ng/mL) than without (30.8 ± 1.2 ng/mL; p = 0.02) portal inflammation and independently associated with the latter; these data need to be confirmed by future studies.
Serum irisin levels differ between lean controls and obese controls or NAFLD patients. Despite similar circulating irisin levels between NAFL and NASH groups, irisin may be independently and positively associated with the presence of portal inflammation. Future clinical and mechanistic studies are needed to confirm and extend these data.
The relationship between NAFLD and retinol-binding protein 4 - an updated systematic review and meta-analysis
2023, Lipids in Health and Disease
Emerging Links between Nonalcoholic Fatty Liver Disease and Neurodegeneration
2023, Seminars in Liver Disease

View all citing articles on Scopus

View full text

Serum retinol binding protein 4 and nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus

Abstract

Introduction

Section snippets

Subjects

Statistical analysis

Results

Discussion

Acknowledgements

Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes

Nature

Retinol-binding protein 4 and insulin resistance in lean, obese, and diabetic subjects

N. Engl. J. Med.

Retinol-binding protein: the serum transport protein for vitamin A

Endocr. Rev.

Association of nonalcoholic fatty liver disease with insulin resistance

Am. J. Med.

Liver diseases and diabetes mellitus

Prog. Liver Dis.

Receiver operating characteristic analysis of glycogenated nuclei in liver biopsy specimens: quantitative evaluation of their relationship with diabetes and obesity

Hum. Pathol.

Prognosis in non-alcoholic steatohepatitis (Letter)

Gastroenterology

Safety and effectiveness of rosiglitazone in type 2 diabetes patients with nonalcoholic Fatty liver disease

J. Formos Med. Assoc.

Effects of rosiglitazone and metformin on liver fat content, hepatic insulin resistance, insulin clearance, and gene expression in adipose tissue in patients with type 2 diabetes

Diabetes

Definition, diagnosis and classification of diabetes mellitus and its complications. 1: Diagnosis and classification of diabetes mellitus, provisional report of a WHO consultation

Diab. Med.

Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man

Diabetologia

Cause specific mortality in type 2 diabetes. The Verona Diabetes study

Diab. Care

CYP2E1 and CYP4A as microsomal catalysts of lipid peroxidase in murine nonalcoholic steatohepatitis

J. Clin. Invest.

The lipid peroxidation end product 4-hydroxy-2,3-nonenal up regulates transformin growth factor B1 expression in the macrophage lineage: a link between oxidation injury and fibrosclerosis

FASEB J.

Mechanisms of disease. Nonalcoholic fatty liver disease

N. Engl. J. Med.