<p>Plasma RBP4 Level in Association with Body Composition, Metabolic Profile, STRA6 and RBP4 Gene Polymorphisms in Obese Romanian Children</p>

Abstract

Background: Pediatric obesity continues to remain a serious health concern which has significantly increased the morbidity risk in adulthood. Recent studies have analyzed the impact of the two adipokines, RBP4 (retinol binding protein 4) and STRA6 (stimulated by retinoic acid 6) in pediatric obese subjects with contradictory results. Methods: An observational study was conducted in the Pediatric and Endocrinology Departments, Targu-Mures, Romania, including 213 children between 5-17 years of age, divided into two groups according to body mass index (BMI) standard deviation score (SDS): case (overweight or obese) and control (normal SDS). Age, sex, basic anthropometric and biochemical measurements and genotype of rs3758539, and rs10882280 for RBP4 gene and rs974456 and rs351224 of STRA6 gene were analyzed. Statistical analysis used SPSS v. 25.0, with a level of significance α = 0.05. Results: There is no association between the two gene's polymorphisms and obesity in our pediatric population. In regression analysis, with HOMA IR (homeostatic model assessment of insulin resistance) as the outcome, the plasmatic level of RBP4 and fat mass percentage are significant predictors, with the model explaining 42% of the HOMA variability. Hypercholesterolemia was significantly associated with male sex, carrying variant allele and heterozygote status of rs10882280 RBP4 gene and wild-type allele rs351224 of STRA6 gene. Conclusion: There is no significant association between obesity and SNPs of the RBP4 and STRA6 in our population, but they seem to play a role in insulin resistance and hypercholesterolemia.

Interplay of retinol binding protein 4 with obesity and associated chronic alterations (Review)

“…RBP4 is an adipokine associated with obesity ( 32 ). RBP4 participates in lipid metabolism by activating RXR and LXR receptors ( 37 ).…”

“…In obesity, white adipose tissue secretes large amounts of adipokines, including RBP4, which have local and systemic effects (retinol homeostasis and transport) and contribute to IR ( 15 , 32 ). The association between elevated serum levels of RBP4 (analyzed by ELISA) and obesity/T2D was reported by Yang et al ( 26 ) in the Chinese population in obese patients with and without diabetes.…”

“…However, no significant association was noted between non-diabetic and diabetic groups, suggesting that hyperglycemia was not associated with elevated serum RBP4 levels ( 33 ). The association between RBP4 and obesity and associated disease has been investigated in humans and animal and cell culture models ( 7 , 9 , 11 , 13 , 18 , 32 – 39 ). In a 10-year follow-up study of 3,445 Chinese school-age children (11–12 years), an association between serum RBP4 levels and adverse cardiovascular risk, metabolic syndrome (MetS), IR, hyperglycemia, hypertension and hyperlipidemia was reported, suggesting that RBP4 may be an early biomarker of MetS ( 11 ).…”

“…However, a positive correlation was noted between concentration of RBP4 in serum (analyzed by ELISA) and levels of TG in obese and control groups ( 36 ). A study of obese Romanian children reported that following adjustment for age, sex and BMI, blood levels of RBP4 (analyzed by ELISA) were not associated with characteristics of MetS (obesity, IR and hypercholesterolemia) body composition (fat and muscle mass) or anthropometric profile (height, BMI, abdominal circumference, tricipital skin-fold thickness, waist circumference/height ratio) ( 32 ). Although controversial results have been published, a correlation between elevated levels of RBP4 in the blood and the incidence of IR, serum lipid levels, and anthropometric parameters has been reported ( 9 , 11 , 32 , 35 – 39 ).…”

“…A study of obese Romanian children reported that following adjustment for age, sex and BMI, blood levels of RBP4 (analyzed by ELISA) were not associated with characteristics of MetS (obesity, IR and hypercholesterolemia) body composition (fat and muscle mass) or anthropometric profile (height, BMI, abdominal circumference, tricipital skin-fold thickness, waist circumference/height ratio) ( 32 ). Although controversial results have been published, a correlation between elevated levels of RBP4 in the blood and the incidence of IR, serum lipid levels, and anthropometric parameters has been reported ( 9 , 11 , 32 , 35 – 39 ). Therefore, population studies implementing different dietary plans have been performed to evaluate the association between weight loss and concentration of adipokines, including RBP4 ( 37 , 38 , 40 ).…”