Association of Serum Retinol Binding Protein 4 with Atherogenic Dyslipidemia in Morbid Obese Patients

Abstract

Retinol binding protein 4 (RBP4) is an adipokine that may contribute to the development of insulin resistance. However, how this adipokine is affected and its possible involvement in lipid metabolism in obese patients with varying degrees of insulin resistance is yet to be determined. A total of 299 middle-aged morbid obese patients (BMI>40 kg/m2) were divided in euglycemic, metabolic syndrome or type 2 diabetic. Anthropometric measurements, biochemical variables and systemic RBP4 levels were determined. RBP4 levels were significantly higher in patients with metabolic syndrome and type 2 diabetes than in euglycemic subjects (42.9±14.6; 42.3±17.0 and 37.4±11.7 µg/ml, respectively) and correlated with triglycerides but not with those of HOMA-IR in the whole population. The multivariate regression model revealed that triglycerides were the strongest predictor of systemic RBP4 levels. Analysis of lipoprotein subfractions in a subpopulation of 80 subjects showed an altered profile of insulin resistant states characterized by higher VLDL, sdLDL and small HDL percentages and lower large HDL percentage. Although RBP4 levels correlated significantly with LDL particle size and small HDL percentage, the latter parameter was independently associated only with RBP4. Our study reveals that systemic RBP4 levels could play an important role in lipid metabolism in morbid obesity, increasing triglyceride levels and contributing to the formation of small HDL.

Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia and insulin sensitivity in healthy subjects: A randomized controlled trial

“…We have previously published evidence that, in insulin resistant states, an increase in fasting triglycerides is associated with a higher percentage of VLDL, which results in smaller, denser LDL particles [14,15]. The atherogenic potential of small and dense LDL particles has been demonstrated in numerous studies [16,17].…”

“…In any case, none of these studies has evaluated the effect of inositols on postprandial glycaemic response, lipoprotein profile or LDL particle size in healthy subjects under free-living conditions. We have previously published evidence of an increase in small and dense LDL particles in subjects with insulin resistance [14,15] that correlated with the progression of atherosclerosis and earlier and more severe cardiovascular disease [16,17]. Therefore, the primary aim of the present study was to assess the chronic consumption of an oral nutritive inositol-enriched beverage (IEB) on glycaemia (in fasting and postprandial states), insulin levels and insulin resistance.…”

Levels of serum retinol‐binding protein 4 before and after non‐surgical periodontal treatment in lean and obese subjects: An interventional study

“…It has been shown that RBP4 is upregulated in insulin‐resistant conditions associated with obesity and provokes IR by interfering with insulin receptor substrate 1 (Gerrits et al., ; Yang et al., ). In addition, it seems to be a predictor of cardiovascular disease (Alkharfy, Al‐Daghri, Vanhoutte, Krishnaswamy, & Xu, ) and development of atherosclerosis, as it promotes atherogenic dyslipidaemia (Rocha et al., ) and is involved in the regulation of hypertension (Kraus et al., ). Recently, it has been established that RBP4 levels in gingival crevicular fluid and serum are positively correlated with body mass index (BMI) and periodontal parameters (Kanoriya, Pradeep, Mallika, Singhal, & Garg, ).…”

“…It has been shown that RBP4 is upregulated in insulin-resistant conditions associated with obesity and provokes IR by interfering with insulin receptor substrate 1 (Gerrits et al, 2012;Yang et al, 2005). In addition, it seems to be a predictor of cardiovascular disease (Alkharfy, Al-Daghri, Vanhoutte, Krishnaswamy, & Xu, 2012) and development of atherosclerosis, as it promotes atherogenic dyslipidaemia (Rocha et al, 2013) and is involved in the regulation of hypertension (Kraus et al, 2015).…”

Adipokines and their Involvement as a Target of New Drugs

“…Although central vaspin administration led to reduced food intake [82,88], the mechanism of action remains unclear. Bluher [89] suggested that vaspin inhibited proteases that degrade molecules with glucose lowering effects as well as anti-orexigenic factors.…”