title: HDL-C, triglycerides and carotid IMT: a meta-analysis of 21,000 patients with automated edge detection IMT measurement.
abstract: OBJECTIVE
  Common carotid artery (CCA) intima-media thickness (IMT), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), but not triglyceride levels, are markers of future cardiovascular events. The relationship between these three factors is, however, unclear.
  
  
  METHODS
  We included six large observational studies that used the same harmonized, B-mode ultrasound protocol, the same software for IMT measurement by automatic edge detection on CCA in a plaque-free region, following the Mannheim consensus, and certification of all sonographers. Using the best view of the CCA, the sonographer had to confirm that the quality index was ≥ 0.5 on a measurement performed on 10-mm length. We used individual data meta-analysis to estimate the cross-sectional associations of lipids with CCA-IMT.
  
  
  RESULTS
  Overall, 21,587 patients with complete information on lipids and CCA-IMT were available. Age- and sex-adjusted CCA-IMT differed by -7.8 μm (95% CI -9.1 to -6.5 μm, P < 0.001) per 1 SD higher HDL-C level. After further adjustment for other atherosclerosis risk factors, the relationship was attenuated, but remained significant (regression coefficient, -3.7 μm; P < 0.001). This was found regardless of LDL-C levels (P for heterogeneity = 0.70). After adjustment for age and sex, triglycerides were positively associated with CCA-IMT, overall and in each LDL-C subgroup, but not after further adjustments for other risk factors.
  
  
  CONCLUSIONS
  Relationships between HDL-C and triglyceride levels and CCA-IMT were consistent with that previously observed with clinical events by the Emergency Risk Collaboration group, including at low LDL-C levels. This reinforces the need to verify whether raising HDL-C levels decreases both CCA-IMT and future clinical events.
authors.affiliation: From INSERM U 698, Paris, France; Paris Diderot - Sorbonne Paris City University, Paris, France; Department of Neurology and Stroke Centre, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France. Electronic address: pjtw@Noos.Pa.
authors.forename: Pierre-Jean
authors.initials: PJ
authors.lastname: Touboul
authors.affiliation: From INSERM U 698, Paris, France; Department of Neurology and Stroke Centre, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Labreuche
authors.affiliation: Department of Endocrinology, Pitié-Salpêtrière University Hospital, Pierre and Marie Curie University, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Bruckert
authors.affiliation: Department of Cardiology, Buenos Aires Italian Hospital, Buenos Aires, Argentina.
authors.forename: Herman
authors.initials: H
authors.lastname: Schargrodsky
authors.affiliation: Department of Neurology, "Gervasutta" Hospital ASS 4, Udine, Italy.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Prati
authors.affiliation: Department of Hematology, S. Bortolo Hospital, Vicenza, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tosetto
authors.affiliation: Hypertension and Cardiovascular Risk Factors Clinic, Clinical Pharmacology Unit, School of Medicine, Universidad Centroccidental Lisandro Alvarado, Barquisimeto, Venezuela.
authors.forename: Rafael
authors.initials: R
authors.lastname: Hernandez-Hernandez
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Kam-Sang
authors.initials: KS
authors.lastname: Woo
authors.affiliation: Department of Cardiology, Buenos Aires Italian Hospital, Buenos Aires, Argentina; InterAmerican Foundation for Clinical Research, New York, USA.
authors.forename: Honorio
authors.initials: H
authors.lastname: Silva
authors.affiliation: Paris Diderot - Sorbonne Paris City University, Paris, France; Department of Biostatistics, Fernand Widal Hospital, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.affiliation: From INSERM U 698, Paris, France; Paris Diderot - Sorbonne Paris City University, Paris, France; Department of Neurology and Stroke Centre, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France. Electronic address: pierre.amarenco@bch.aphp.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Amarenco
mesh_terms: D000328:Adult; D001794:Blood Pressure; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging* / Q000503:physiopathology; D059168:Carotid Intima-Media Thickness; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D010363:Pattern Recognition, Automated; D012044:Regression Analysis; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood / Q000378:metabolism*; D014463:Ultrasonography
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides
keywords: Carotid arteries; Lipids; Meta-analysis