title: Circulating Soluble IL-6 Receptor Concentration and Visceral Adipocyte Size Are Related to Insulin Resistance in Taiwanese Adults with Morbid Obesity.
abstract: Morbid obesity is related to chronic inflammation and many metabolic complications. Interleukin (IL)-6 plays a pivotal pathophysiological role in obesity, and IL-6 trans-signaling through the soluble IL-6 receptor (sIL-6R) has a major proinflammatory effect. The aim of this study was to investigate the association between sIL-6R, adipocyte size, and insulin resistance in morbidly obese individuals.
  
  
  
  We measured concentrations of sIL-6R, high-sensitivity C-reactive protein, and lipid parameters and estimated homeostasis model assessment of insulin resistance (HOMA-IR) before the patients underwent bariatric surgery. Mesenteric adipose tissue was collected during surgery, and adipocyte size and concentrations of membrane-bound IL-6 receptor (mIL-6R) were evaluated. In total, 35 adults (20 men and 15 women) were recruited.
  
  
  
  The subjects with high HOMA-IR (≥2.4) had higher fasting glucose/insulin, triglycerides, sIL-6R, and adipocyte size and lower high-density lipoprotein cholesterol and mIL-6R than those with low HOMA-IR (<2.4). Adipocyte size positively correlated with sIL-6R (r = 0.559, P = 0.001) and HOMA-IR (r = 0.773, P ≤ 0.001) independent of age, gender, body mass index (BMI), waist, and use of diabetic drugs. In addition, every 1 ng/mL increase in sIL-6R concentration corresponded to a 10.2% decrease in the likelihood of maintaining lower insulin resistance. Furthermore, an sIL-6R level of 77.45 ng/mL was a reasonable cutoff level to propose lower insulin resistance in morbidly obese subjects.
  
  
  
  Circulating sIL-6R is more closely associated with insulin resistance status than waist-to-hip ratio or BMI in morbidly obese Taiwanese adults. sIL-6R may be a useful biomarker to assess insulin resistance among morbidly obese subjects.
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Feng-Chih
authors.initials: FC
authors.lastname: Kuo
authors.affiliation: 2 Clinical Laboratory Section, Cardinal Tien Hospital , New Taipei City, Taiwan .|3 School of Public Health, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Ya-Hsien
authors.initials: YH
authors.lastname: Huang
authors.affiliation: 3 School of Public Health, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Fu-Huang
authors.initials: FH
authors.lastname: Lin
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Hung
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Chang-Hsun
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Chieh-Hua
authors.initials: CH
authors.lastname: Lu
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Sheng-Chiang
authors.initials: SC
authors.lastname: Su
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Chia-Luen
authors.initials: CL
authors.lastname: Huang
authors.affiliation: 1 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan .
authors.forename: Chien-Hsing
authors.initials: CH
authors.lastname: Lee
authors.affiliation: 3 School of Public Health, National Defense Medical Center , Taipei, Taiwan .|4 Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan .
authors.forename: Nain-Feng
authors.initials: NF
authors.lastname: Chu
mesh_terms: D017667:Adipocytes / Q000648:ultrastructure*; D000328:Adult; D050110:Bariatric Surgery; D015415:Biomarkers; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D048429:Cell Size; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D050152:Intra-Abdominal Fat / Q000648:ultrastructure*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000235:genetics* / Q000473:pathology; D019947:Receptors, Interleukin-6 / Q000097:blood* / Q000235:genetics*; D013624:Taiwan; D049629:Waist-Hip Ratio
chemical_list: D015415:Biomarkers; C508603:IL6R protein, human; D008055:Lipids; D019947:Receptors, Interleukin-6; D002097:C-Reactive Protein
keywords: adipocyte; gp130 IL-6 family receptor; insulin resistance; morbid obesity