title: Abnormalities of lipoprotein concentrations in obstructive sleep apnea are related to insulin resistance.
abstract: OBJECTIVE
  Prevalence of cardiovascular disease (CVD) is increased in patients with obstructive sleep apnea (OSA), possibly related to dyslipidemia in these individuals. Insulin resistance is also common in OSA, but its contribution to dyslipidemia of OSA is unclear. The study's aim was to define the relationships among abnormalities of lipoprotein metabolism, clinical measures of OSA, and insulin resistance.
  
  
  METHODS
  Cross-sectional study. OSA severity was defined by the apnea-hypopnea index (AHI) during polysomnography. Hypoxia measures were expressed as minimum and mean oxygen saturation, and the oxygen desaturation index. Insulin resistance was quantified by determining steady-state plasma glucose (SSPG) concentrations during the insulin suppression test. Fasting plasma lipid/lipoprotein evaluation was performed by vertical auto profile methodology.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  107 nondiabetic, overweight/obese adults.
  
  
  RESULTS
  Lipoprotein particles did not correlate with AHI or any hypoxia measures, nor were there differences noted by categories of OSA severity. By contrast, even after adjustment for age, sex, and BMI, SSPG was positively correlated with triglycerides (r = 0.30, P < 0.01), very low density lipoprotein (VLDL) and its subclasses (VLDL1+2) (r = 0.21-0.23, P < 0.05), and low density lipoprotein subclass 4 (LDL4) (r = 0.30, P < 0.01). SSPG was negatively correlated with high density lipoprotein (HDL) (r = -0.38, P < 0.001) and its subclasses (HDL2 and HDL3) (r = -0.32, -0.43, P < 0.01), and apolipoprotein A1 (r = -0.33, P < 0.01). Linear trends of these lipoprotein concentrations across SSPG tertiles were also significant.
  
  
  CONCLUSIONS
  Pro-atherogenic lipoprotein abnormalities in obstructive sleep apnea (OSA) are related to insulin resistance, but not to OSA severity or degree of hypoxia. Insulin resistance may represent the link between OSA-related dyslipidemia and increased cardiovascular disease risk.
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Alice
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: James
authors.initials: J
authors.lastname: Cardell
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Danit
authors.initials: D
authors.lastname: Ariel
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Lamendola
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Fahim
authors.initials: F
authors.lastname: Abbasi
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Sun H
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Stanford Sleep Medicine Center, Stanford University School of Medicine, Stanford, CA.
authors.forename: Tyson H
authors.initials: TH
authors.lastname: Holmes
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Tomasso
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Hafasa
authors.initials: H
authors.lastname: Mojaddidi
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Kaylene
authors.initials: K
authors.lastname: Grove
authors.affiliation: Stanford Sleep Medicine Center, Stanford University School of Medicine, Stanford, CA.
authors.forename: Clete A
authors.initials: CA
authors.lastname: Kushida
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA.
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Reaven
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood / Q000150:complications / Q000503:physiopathology; D003430:Cross-Sectional Studies; D050171:Dyslipidemias / Q000097:blood* / Q000150:complications* / Q000503:physiopathology; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications / Q000503:physiopathology; D050177:Overweight / Q000097:blood / Q000150:complications / Q000503:physiopathology; D010100:Oxygen / Q000378:metabolism; D017286:Polysomnography; D015995:Prevalence; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000150:complications* / Q000503:physiopathology; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D008074:Lipoproteins; D014280:Triglycerides; D010100:Oxygen
keywords: cardiovascular disease; lipoprotein subclasses; dyslipidemia; lin resistance; obstructive sleep apnea