title: Influence of environmental factors on facial ageing.
abstract: BACKGROUND
  A recent twin study has shown that 'looking old for one's age' is associated with increased mortality. Approximately 40% of the variation in perceived age is due to non-genetic factors.
  
  
  OBJECTIVE
  To examine environmental factors influencing perceived age controlling for diseases.
  
  
  METHODS
  A twin study.
  
  
  METHODS
  In the 2001 wave of the population-based survey--the Longitudinal Study of Aging Danish Twins--participants provided information on a wide range of exposures and health indicators. Additionally, they were asked to have a face photograph taken.
  
  
  METHODS
  A total of 1826 elderly (70+) twins who had a high-quality face photograph taken.
  
  
  METHODS
  Ten nurses assessed the visual age of each twin from the face photograph. The mean of the nurses' age estimates for each twin was used as the twin's perceived age. Multivariate linear regression and intrapair comparison (for intact twin pairs) were used for analyses.
  
  
  RESULTS
  Statistically significant determinants of facial ageing associated with high perceived age for men were smoking (P = 0.01), sun exposure (P = 0.02) and low body mass index (BMI) (P<0.005), while for women they were low BMI (P = 0.05) and low social class (P<0.005). The number of children (men) and marital status (P = 0.08) and depression symptomatology score (women) were borderline significantly associated with facial ageing.
  
  
  CONCLUSIONS
  Our study confirms previous findings of a negative influence of sun exposure, smoking and a low BMI on facial ageing. Furthermore, our study indicates that high social status, low depression score and being married are associated with a younger look, but the strength of the associations varies between genders.
authors.affiliation: The Danish Twin Registry, Epidemiology, Institute of Public Health, University of Southern Denmark, DK-5000 Odense, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Rexbye
authors.forename: Inge
authors.initials: I
authors.lastname: Petersen
authors.forename: Mette
authors.initials: M
authors.lastname: Johansens
authors.forename: Louise
authors.initials: L
authors.lastname: Klitkou
authors.forename: Bernard
authors.initials: B
authors.lastname: Jeune
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D015992:Body Mass Index; D003863:Depression; D005260:Female; D006304:Health Status; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D012725:Sexual Behavior; D015595:Skin Aging / Q000502:physiology* / Q000528:radiation effects; D012907:Smoking / Q000009:adverse effects; D012959:Socioeconomic Factors; D013472:Sunlight / Q000009:adverse effects; D018433:Twin Studies as Topic