title: Decreased lipoprotein lipase in obstructive sleep apnea syndrome.
abstract: BACKGROUND
  Lipoprotein lipase (LPL) might play a major role in lipid metabolism by hydrolyzing triglyceride-rich lipoproteins. Decreased LPL activity can trigger early inflammatory responses central to atherosclerosis. However, whether repeated apnea-related hypoxemia influences lipid metabolism in patients with obstructive sleep apnea syndrome (OSAS) remain undefined. This investigation determined whether circulating LPL was influenced by repeated apnea-related hypoxemia, and the effect of nasal continuous positive airway pressure (CPAP) therapy on LPL concentrations in OSAS patients.
  
  
  RESULTS
  The participants of the study were 155 men with OSAS and 39 men without OSAS. Circulating LPL concentrations decreased with the severity of OSAS. They correlated negatively with serum triglyceride, and the linear regression lines between LPL concentrations and triglyceride in OSAS patients were shifted downward compared with those in non-OSAS patients, suggesting that any pathophysiological factor might decrease LPL activity in OSAS patients. Some OSAS patients were subjected to CPAP therapy for 3 months. CPAP therapy increased LPL concentrations and decreased C-reactive protein (CRP) concentrations.
  
  
  CONCLUSIONS
  The present study suggests that repeated apnea-related hypoxemia might affect lipid metabolism and augment inflammatory responses, and CPAP therapy could be effective to decrease inflammatory responses and ameliorate lipid metabolism in patients with OSAS.
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Iesato
authors.forename: Koichiro
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Toshiji
authors.initials: T
authors.lastname: Saibara
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Jiro
authors.initials: J
authors.lastname: Terada
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tada
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Sakao
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tanabe
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takiguchi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kuriyama
mesh_terms: D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D045422:Continuous Positive Airway Pressure; D006801:Humans; D007249:Inflammation; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000201:enzymology* / Q000378:metabolism
chemical_list: D002097:C-Reactive Protein; D008071:Lipoprotein Lipase