title: A comparison of osteoprotegerin with adiponectin and high-sensitivity C-reactive protein (hsCRP) as a marker for insulin resistance.
abstract: OBJECTIVE
  Insulin resistance (IR) is associated with low adiponectin and elevated high sensitivity C-reactive protein (hsCRP). Osteoprotegerin (OPG) has been shown to be elevated in type 2 diabetes, but whether it reflects underlying IR is unclear. We aimed to compare the ability of serum OPG with adiponectin and hsCRP to act as a marker for IR in individuals with normal and abnormal glucose tolerance.
  
  
  METHODS
  115 men underwent a 75 g oral glucose tolerance test. OPG, hsCRP and adiponectin were measured using ELISA. IR was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR).
  
  
  RESULTS
  Men with abnormal glucose tolerance (n=38) were older (58.3±11.2 vs 47.3±11.4 years, P<.001), had higher body mass index (BMI) (31.1±2.9 vs 27.9±3.2 kg/m(2), P<.001) and were more insulin resistant (median (I.Q.) HOMA-IR 5.88 (3.38) vs 1.13 (1.14), P<.001) than those with normal glucose tolerance (n=77). After adjustment for age and BMI, OPG (6.28 (2.32) vs 5.16 (1.86) pmol/L, P<.001) and hsCRP (2.07 (5.47) vs 0.78 (1.05) mg/L, P<.001) were higher and adiponectin (3.02±1.17 vs 4.78±2.38 μg/mL, P<.001) was lower in those with AGT. After adjustment for age and BMI, adiponectin (r=-0.317, P<.001) and hsCRP (r=0.318, P<.001), but not OPG (r=0.126, P=.196) correlated with HOMA-IR. On multiple linear regression analysis, adiponectin and hsCRP but not OPG were independent predictors of HOMA-IR.
  
  
  CONCLUSIONS
  OPG is higher in individuals with abnormal glucose tolerance, but unlike adiponectin and hsCRP, does not correlate with HOMA-IR, suggesting its elevation within this cohort of individuals is due to factors other than insulin resistance.
authors: Department of Diabetes and Endocrinology, Royal College of Surgeons in Ireland Medical School, Beaumont Hospital, Dublin 9, Ireland.
authors: Eoin P
authors: EP
authors: O'Sullivan
authors: David T
authors: DT
authors: Ashley
authors: Colin
authors: C
authors: Davenport
authors: Lakshmi
authors: L
authors: Penugonda
authors: Grainne
authors: G
authors: Kelleher
authors: Niamh
authors: N
authors: Devlin
authors: Rachel
authors: R
authors: Crowley
authors: Paula
authors: P
authors: O'Shea
authors: Amar
authors: A
authors: Agha
authors: Chris J
authors: CJ
authors: Thompson
authors: Donal J
authors: DJ
authors: O'Gorman
authors: Diarmuid
authors: D
authors: Smith
mesh_terms: D052242:Adiponectin / Q000097:blood*; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D053244:Osteoprotegerin / Q000097:blood*
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D053244:Osteoprotegerin; D002097:C-Reactive Protein