title: Characteristic features of ageing in Korean women's hair and scalp.
abstract: BACKGROUND
  The effect of age on hair properties has previously been investigated in white and Japanese women; however, little is known of the age-related characteristic features of hair in Korean women.
  
  
  OBJECTIVE
  To determine the ageing features of Korean women's hair by examining physical and biological factors in sufficient numbers of participants.
  
  
  METHODS
  In total, 150 healthy Korean women (aged 23-69 years) living in Seoul were allocated to five age-graded groups. Age-related changes of various features of the scalp and hair shaft were measured, including hair density, diameter, tensile strength and lustre, and grey-hair ratio. The hair-shaft compositions of minerals, amino acids and steroid hormones were analysed by high-performance liquid chromatography.
  
  
  RESULTS
  Hair-loss parameters (hair density, diameter and tensile strength) and hair lustre decreased significantly with age, beginning in the subjects' 40s. The hair-whiteness value increased significantly with age, beginning in their 60s, due to an increase in the ratio of grey hair. Calcium and magnesium levels greatly exceeded the reference ranges and declined in an age-dependent manner, while potassium and phosphorus levels increased with age. No age-related change of hair-shaft amino acid content was evident. The contents of sterols and their metabolites (cholesterol, desmosterol, lanosterol and pregnenolone) increased significantly with age, but there was no correlation between the examined sex steroids and age.
  
  
  CONCLUSIONS
  These results show that intrinsic ageing produces diverse changes in the hair and scalp features of Korean women from their 40s, and the ageing features of Korean women's hair could be partially different from that of women in other countries.
authors.affiliation: Advanced Hair Research Laboratory, Gyeonggi-do, South Korea.
authors.forename: S N
authors.initials: SN
authors.lastname: Kim
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: M H
authors.initials: MH
authors.lastname: Choi
authors.forename: K M
authors.initials: KM
authors.lastname: Joo
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: J S
authors.initials: JS
authors.lastname: Koh
authors.forename: W S
authors.initials: WS
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000596:Amino Acids / Q000032:analysis; D044466:Asian People; D002853:Chromatography, Liquid / Q000379:methods; D005260:Female; D012739:Gonadal Steroid Hormones / Q000032:analysis; D006197:Hair / Q000737:chemistry / Q000502:physiology*; D006200:Hair Color / Q000502:physiology; D018859:Hair Follicle / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D008903:Minerals / Q000032:analysis; D056910:Republic of Korea; D012535:Scalp / Q000502:physiology*; D013718:Tensile Strength / Q000502:physiology; D055815:Young Adult
chemical_list: D000596:Amino Acids; D012739:Gonadal Steroid Hormones; D008903:Minerals