Changes of serum retinol-binding protein 4 associated with improved insulin resistance after laparoscopic sleeve gastrectomy in Chinese obese patients

Abstract

Background: Serum retinol-binding protein 4 (RBP4) plays a critical role in insulin resistance. The mechanism behind the impact of laparoscopic sleeve gastrectomy (LSG) on glucose metabolism is unclear. Hence, we aimed to investigate the triangle relationship between the RBP4, glucose metabolism, and LSG in patients of Chinese ethnicity. Methods:The study enrolled eighty-two obese patients. Glucose-lipid metabolic index, uric acid (UA), superoxide dismutase (SOD), free triiodothyronine (FT3), free thyroxin (FT4) and thyrotropin (TSH) were measured. RBP4 levels were detected by enzyme-link immunosorbent assay. 30 obese patients underwent LSG were studied. All these markers were measured again at a time interval of 3 and 6 months after surgery. Results:(1) Circulating RBP4 levels were positively associated with body mass index(BMI), blood glucose in 0 min (BG0), BG30, BG120, BG180, fasting inulin(FINS), fasting C peptide(FCP), homeostasis model of assessment for insulin resistance index (HOMA-IR), SOD, TSH and negatively associated with Matsuda index in obesity with a significant difference (P < 0.05). RBP4 levels in the patients with impaired fasting glucose (IFG), insulin resistance or hyperinsulinemia were significantly higher than the patients without IFG, insulin resistance or hyperinsulinemia (P = 0.035, P = 0.001, and P = 0.007).(2) LSG resulted in significantly decreased FBG, FINS, FCP and HOMA-IR at 3, 6 months after surgery (all P < 0.05). The RBP4 levels were significantly decreased after surgery (all P < 0.05) with no gender difference. (3) The change in RBP4 levels was significantly associated with the change in FINS, FCP, HOMA-IR, and HOMA-β at 6 months and the change in TSH at 3 months after surgery in males (all P < 0.05). The change in RBP4 levels were significantly associated with the change in FINS, FCP, HOMA-IR, HOMA-β, and TCH at 3 months after surgery in females (all P < 0.05). Conclusions:Overall, our results interpret the significant correlations between RBP4, glucose-lipid metabolism, oxidative stress and thyroid function in obese patients. Further, the LSG brings a decline in RBP4 levels and that may contribute partly to the improved insulin resistance in obese Chinese patients.

Adipose-Derived Lipid-Binding Proteins: The Good, the Bad and the Metabolic Diseases

“…(ii) a positive association between serum RBP4, insulin resistance and adiposity [20,22]; (iii) a negative association (or inverse correlation) between serum RBP4 and HDL levels [20]. Similar results are observed in obese children [23].…”

“…Several publications report (i) high RBP4 concentration in plasma or high levels of RBP4 mRNA in adipose tissue of obese, diabetic individuals and their close relatives [ 20 , 21 ]; (ii) a positive association between serum RBP4, insulin resistance and adiposity [ 20 , 22 ]; (iii) a negative association (or inverse correlation) between serum RBP4 and HDL levels [ 20 ]. Similar results are observed in obese children [ 23 ].…”

“…Similar results are observed in obese children [ 23 ]. Others also report a decrease in circulating RBP4 associated with an increase of insulin sensitivity during weight loss, subsequent to exercise training, low calorie diet or gastrectomy [ 20 , 22 ]. Moreover, RBP4 plasma concentrations are positively associated with blood pressure and atherosclerotic plaque in obese patients [ 24 ].…”

Correlation and Diagnostic Value of Serum RBP4 and sRAGE and the Condition of Patients with Chronic Kidney Disease

“…It is often present in the blood as a complex. e decomposed and free RBP4 is mostly absorbed and decomposed by the renal tubules after being filtered by the glomeruli [21][22][23]. RAGE is a multi-ligand transmembrane signal transduction receptor circulating in human blood.…”

Impact of Gastric Sleeve Surgery on Plasma Retinol Binding Protein 4 and Adipsin Levels in Healthy Male Population

“…Although gender-based differences were present in glucose and lipid metabolism parameters depending upon time after surgery. 19 Thus, various factors such as race, gender, study population and detection methods regulate RBP4 levels. Our study samples consisted of only male patients, therefore it would be interesting to repeat this study in a larger sample size including female subjects to understand the role RBP4 in this population.…”