title: Oxidized Low Density Lipoprotein Among the Elderly in Qinghai-Tibet Plateau.
abstract: OBJECTIVE
  Several environmental factors including hypoxia have been reported to contribute to oxidative stress in individuals living in the highlands. However, little is known about the role of oxidized low-density lipoprotein (ox-LDL) among community-dwelling elderly in the Qinghai-Tibet plateau.
  
  
  METHODS
  The study population comprised 168 community-dwelling elderly subjects aged 60 years or older (male to female ratio, 70:98; mean age, 65.8 years) living in Haiyan County, located 3000 to 3200 m above sea level, 30 km northwest of Xining, Qinghai. The subjects were volunteers who joined a Comprehensive Geriatric Assessment. Plasma ox-LDL was measured in 168 community-dwelling elderly subjects aged 60 years or older (23 Tibetans and 145 Hans) with a monoclonal antibody-based enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Mean ox-LDL level was higher among Tibetan elderly than Han elderly (Tibetan, 79.0 ± 29.6 U/L; Han, 62.8 ± 23.5 U/L; P = .003). Tibetan ethnicity was significantly associated with ox-LDL levels after adjusting for LDL cholesterol levels. In addition, high ox-LDL levels (≥70 U/L) were significantly associated with a homeostasis model assessment insulin resistance index of at least 1.6 (odds ratio [OR], 2.82; 95% confidence interval [95% CI], 1.11 to 7.15; P = .029) and ankle brachial pressure index of less than 1.0 (OR, 4.85; 95% CI, 1.14 to 10.00; P = .028), after adjusting for age, sex, and ethnicity.
  
  
  CONCLUSIONS
  Our findings support the hypothesis that ox-LDL levels are higher among Tibetan elderly highlanders compared with those among Han elderly. As ox-LDL levels can affect insulin resistance and arteriosclerosis, further research is needed to determine how oxidative stress influences the health situation among elderly individuals at high altitudes.
authors.affiliation: Hakubi Center for Advanced Research, Kyoto, Japan (Dr Sakamoto); Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi); Research Institute for Humanity and Nature, Kyoto, Japan (Drs Sakamoto and Okumiya). Electronic address: sakamoto65@cseas.kyoto-u.ac.jp.
authors.forename: Ryota
authors.initials: R
authors.lastname: Sakamoto
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi); Research Institute for Humanity and Nature, Kyoto, Japan (Drs Sakamoto and Okumiya).
authors.forename: Kiyohito
authors.initials: K
authors.lastname: Okumiya
authors.affiliation: Hakubi Center for Advanced Research, Kyoto, Japan (Dr Sakamoto).
authors.forename: Hongxin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Affiliated Hospital of Qinghai University, Qinghai, China (Drs Wang and Dai).
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Dai
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Michiko
authors.initials: M
authors.lastname: Fujisawa
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Taizo
authors.initials: T
authors.lastname: Wada
authors.affiliation: Department of Field Medicine, School of Public Health, Kyoto University, Kyoto, Japan (Drs Imai and Matsubayashi; Ms Chen).
authors.forename: Hissei
authors.initials: H
authors.lastname: Imai
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Ishimoto
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Eriko
authors.initials: E
authors.lastname: Fukutomi
authors.affiliation: Department of Field Medicine, School of Public Health, Kyoto University, Kyoto, Japan (Drs Imai and Matsubayashi; Ms Chen).
authors.forename: Wingling
authors.initials: W
authors.lastname: Chen
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Kwanchit
authors.initials: K
authors.lastname: Sasiwongsaroj
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi).
authors.forename: Emiko
authors.initials: E
authors.lastname: Kato
authors.affiliation: Research Center for High Altitude Medicine, Qinghai University, Qinghai, China (Dr Ge).
authors.forename: Ri-Li
authors.initials: RL
authors.lastname: Ge
authors.affiliation: Center for Southeast Asian Studies, Kyoto, Japan (Drs Sakamoto, Okumiya, Fujisawa, Wada, Kimura, Ishimoto, Fukutomi, Sasiwongsaroj, Kato, and Matsubayashi); Department of Field Medicine, School of Public Health, Kyoto University, Kyoto, Japan (Drs Imai and Matsubayashi; Ms Chen).
authors.forename: Kozo
authors.initials: K
authors.lastname: Matsubayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay; D005006:Ethnicity; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008077:Lipoproteins, LDL / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress
chemical_list: D015415:Biomarkers; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein
keywords: Elderly people; Han; High altitude; Ox-LDL; Oxidative stress; Tibetan