title: A new look at the genetic and environmental coherence of metabolic syndrome components.
abstract: OBJECTIVE
  Metabolic syndrome, a clustering of risk factors including insulin resistance, dyslipidemia, central obesity, and hypertension, increases risk for cardiovascular disease and cognitive decline. The etiology of the risk factors' cohesion remains unclear. How genetic and environmental influences explained co-occurrence of metabolic syndrome components was examined.
  
  
  METHODS
  Continuous measures of body mass index (BMI), waist circumference, blood pressure (BP), fasting insulin and glucose, high-density lipoprotein cholesterol (HDL), and triglycerides from 1,193 middle-aged twin men participating in the Vietnam Era Twin Study of Aging at average age 62 (range 56-67) were analyzed using multivariate biometrical modeling.
  
  
  RESULTS
  Four heritable factors were found: adiposity (BMI, waist circumference), insulin resistance (glucose, insulin), lipids (HDL, triglycerides), and BP (systolic, diastolic). Heritabilities were 0.42-0.68. In the best-fitting model, insulin resistance, lipids, and adiposity comprised a higher-order latent genetic factor. Adiposity and BP shared genetic influences independent of the latent genetic factor. All factors aggregated on a latent unique environmental factor.
  
  
  CONCLUSIONS
  Metabolic syndrome components form the equivalent of two genetic factors. BP was genetically unrelated to insulin resistance and lipids. Adiposity was the only characteristic genetically and environmentally related to all other factors. These results inform strategies for gene discovery and prediction of health outcomes.
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Panizzon
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.|Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, California, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Hauger
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Sailors
authors.affiliation: Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lyons
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois, USA.
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Jacobson
authors.affiliation: Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Murray McKenzie
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.
authors.forename: Brinda
authors.initials: B
authors.lastname: Rana
authors.affiliation: Department of Anesthesiology and Orthopaedics and Rehabilitation, University of Florida, Gainesville, Florida, USA.
authors.forename: Terrie
authors.initials: T
authors.lastname: Vasilopoulos
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.|Department of Public Health, University of Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Vuoksimaa
authors.affiliation: Department of Biostatistics, St. Louis University, St. Louis, Missouri, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Xian
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.|Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, California, USA.
authors.forename: William S
authors.initials: WS
authors.lastname: Kremen
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, California, USA.
authors.forename: Carol E
authors.initials: CE
authors.lastname: Franz
mesh_terms: D050154:Adiposity / Q000235:genetics; D000368:Aged; D001699:Biometry; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000235:genetics; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology*; D008076:Cholesterol, HDL / Q000097:blood; D004777:Environment; D005215:Fasting / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000235:genetics; D008055:Lipids / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000150:complications / Q000235:genetics*; D008875:Middle Aged; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin; D008055:Lipids; D014280:Triglycerides