Serum Retinol Binding Protein-4 and Insulin Resistance in Post-menopausal Women with Cardiovascular Disease

¹Applied Medical Chemistry Department, Medical Research Institute, Alexandria University, Alexandria, Egypt

² Chemical Pathology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt

³ clinical and experimental internal medicine Department, Medical Research Institute, Alexandria University, Alexandria, Egypt

^*Corresponding Author

Samir Ali Abd El-Kaream

Applied Medical Chemistry Department

Medical Research Institute

Alexandria University

Alexandria 2(03), Egypt

E-mail: samir_ali852006@yahoo.com

Abstract

Background: Retinol binding protein-4 (RBP-4) is a newly discovered adipokine, which is mainly secreted by liver and originally known to be the only specific transport protein for vitamin A in the circulation. Recently, RBP-4 is found to be expressed in adipose tissue and correlated with obesity, insulin resistance (IR) and type 2 diabetes mellitus (T2DM). It is well known that there is a higher prevalence of cardiovascular risk factors and metabolic syndrome (MS) in postmenopausal women. Postmenopausal status is believed to be a risk factor for IR in women. IR has a causal role in the development of T2DM. Even in the absence of hyperglycemia or diabetes, IR contributes to an increased risk of cardiovascular disease (CVD).

Objective: The aim of the present work was to evaluate the influence of menopausal status on RBP-4 concentration and to investigate the association of plasma RBP-4 with IR in post-menopausal women with and without CVD.

Subjects and Methods: The present study included 25 apparently healthy premenopausal women, 25 apparently healthy postmenopausal women and 25 postmenopausal women With CVD. Blood samples were collected from all subjects and the level of plasma RBP-4 and plasma insulin were measured by enzyme linked immunossorbent assay (ELISA).

Results: RBP-4 concentrations in postmenopausal women were higher than those in premenopausal women. Postmenopausal women with CVD have higher plasma RBP-4 concentrations than in healthy postmenopausal women and were positively correlated with age, TC, TG, TG/HDL-C, fasting plasma glucose, postprandial glucose, plasma insulin, HOMA-IR and ALT.

Conclusions: Postmenopausal women with CVD showed significantly higher plasma RBP-4, blood pressure (systolic and diastolic), lipid profile (TC, LDL-C, TG and TG/HDL-C ratio), insulin and HOMA-IR than those in postmenopausal women. In addition, RBP-4 significantly positively correlated with FG, postprandial glucose, insulin, HOMA-IR, TC, TG, TG/HDL-C ratio and ALT.

Keywords: Retinol binding protein-4, insulin resistance, cardiovascular disease, Postmenopausal women.

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