Oxidized Low Density Lipoprotein Among the Elderly in Qinghai-Tibet Plateau

• Published in: Wilderness & environmental medicine Vol. 26; no. 3; pp. 343 - 349
• Main Authors: Sakamoto, Ryota, MD, PhD, Okumiya, Kiyohito, MD, PhD, Wang, Hongxin, MD, Dai, Qingxiang, MD, Fujisawa, Michiko, MD, PhD, Wada, Taizo, MD, PhD, Imai, Hissei, MD, PhD, Kimura, Yumi, PhD, Ishimoto, Yasuko, PhD, Fukutomi, Eriko, PhD, Chen, Wingling, MPH, Sasiwongsaroj, Kwanchit, PhD, Kato, Emiko, MD, Ge, Ri-Li, PhD, Matsubayashi, Kozo, MD, PhD
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Elsevier Inc 01.09.2015; SAGE Publications
• Subjects: Aged; Aged, 80 and over; Biomarkers - metabolism; China; Elderly people; Emergency; Enzyme-Linked Immunosorbent Assay; Ethnic Groups; Female; Geriatric Assessment; Han; High altitude; Humans; Lipoproteins, LDL - genetics; Lipoproteins, LDL - metabolism; Male; Middle Aged; Ox-LDL; Oxidative Stress; Tibetan; Elderly people; Oxidative stress; High altitude; Han; Tibetan; Ox-LDL
• ISSN: 1080-6032; 1545-1534
• DOI: 10.1016/j.wem.2015.03.025

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.