title: Heritability of arterial stiffness and carotid intima-media thickness: an Italian twin study.
abstract: OBJECTIVE
  Carotid intima-media thickness (IMT) and arterial stiffness parameters, including aortic augmentation index (AIx) and pulse wave velocity (PWV), are independent predictors of stroke and cardiovascular disease. Genetic effects on these traits were never explored in a Mediterranean country. The present study aims to quantify the contribution of genes, environment and age to carotid IMT and aortic Aix and PWV.
  
  
  RESULTS
  The twin design was used. A total of 348 adult twins from the Italian Twin Register underwent measurements of carotid IMT and aortic PWV and AIx in three university hospitals located in Rome, Padua and Perugia. Carotid IMT was measured by B-mode ultrasound, aortic PWV and AIx by Arteriograph. Genetic modelling was performed to decompose total variance of traits into genetic, shared and unshared environmental and age components. For each phenotype, the best-fitting model included additive genetic, unshared environmental and age effects. For IMT, heritability was 0.32 (95% confidence interval (CI): 0.25-0.38), unshared environmental component was 0.25 (0.18-0.32) and age contribution was 0.44 (0.39-0.49). For AIx and PWV, heritabilities were 0.42 (0.29-0.55) and 0.49 (0.35-0.62), unshared environmental components were 0.31 (0.22-0.44) and 0.37 (0.26-0.51) and age contributions were 0.27 (0.16-0.39) and 0.14 (0.06-0.24), respectively.
  
  
  CONCLUSIONS
  This study shows substantial genetic and unshared environmental influences on carotid intima-media thickness and arterial stiffness and confirms the relevant role of age in the aetiology of these traits. Further support is provided for prevention and health promotion strategies based on modifiable factors.
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Medda
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy. Electronic address: corrado.fagnani@iss.it.
authors.forename: C
authors.initials: C
authors.lastname: Fagnani
authors.affiliation: University of Perugia, Department of Medicine and Unit of Internal Medicine, Terni University Hospital, Terni, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Schillaci
authors.affiliation: Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
authors.forename: A D
authors.initials: AD
authors.lastname: Tarnoki
authors.affiliation: Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary.
authors.forename: D L
authors.initials: DL
authors.lastname: Tarnoki
authors.affiliation: Department of Neurosciences, School of Medicine, University of Padua, Padua, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Baracchini
authors.affiliation: Department of Neurosciences, School of Medicine, University of Padua, Padua, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Meneghetti
authors.affiliation: Department of Radiological Sciences, La Sapienza University of Rome, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Fanelli
authors.affiliation: University of Perugia, Department of Medicine and Unit of Internal Medicine, Terni University Hospital, Terni, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Alaeddin
authors.affiliation: University of Perugia, Department of Medicine and Unit of Internal Medicine, Terni University Hospital, Terni, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pucci
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Alviti
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cotichini
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Brescianini
authors.affiliation: Department of Radiological Sciences, La Sapienza University of Rome, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Boatta
authors.affiliation: Department of Radiological Sciences, La Sapienza University of Rome, Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Lucatelli
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Nisticò
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Penna
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Salemi
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Toccaceli
authors.affiliation: Department of Radiological Sciences, La Sapienza University of Rome, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Zini
authors.affiliation: The Methodist Hospital DeBakey Heart and Vascular Center, Houston, TX, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Garami
authors.affiliation: Istituto Superiore di Sanità, National Centre for Epidemiology, Surveillance and Health Promotion, Genetic Epidemiology Unit, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Stazi
mesh_terms: D000328:Adult; D000368:Aged; D001011:Aorta / Q000378:metabolism; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging / Q000235:genetics; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D059168:Carotid Intima-Media Thickness; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D012307:Risk Factors; D059289:Vascular Stiffness / Q000235:genetics*
keywords: Augmentation index; Carotid thickness; Pulse wave velocity; Twin study