Original Study Cross-Sectional Study Examining the Association Between Metabolic Syndrome and Cognitive Function Among the Oldest Old Li Luo MD, Ming Yang MD, Qiukui Hao MD, Jirong Yue MD, Birong Dong MD * Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, China Keywords: Metabolic syndrome cognitive impairment nonagenarians centenarians abstract Objectives: Metabolic syndrome (MetS), which includes obesity, hypertension, dyslipidemia, and insulin resistance, has been shown to predispose people to cognitive impairment and dementia. In this study, we aimed to examine the relationship between MetS and cognitive impairment among the oldest-old people using a cohort of Chinese individuals aged 90 to 108 years. Methods: The Project of Longevity and Aging in Dujiangyan is a population-based study of 870 people aged 90 years and older. Cognitive function was evaluated using Mini-Mental State Examination, and venous blood samples were collected after an overnight fast to measure the biochemistry indicators. Results: Among the 767 participants for this analysis, the mean age was 93.6  3.3 years (range 90e108 years), 516 (67.3%) were women, and 53 were centenarians. The mean Mini-Mental State Examination score was 15.0  5.9. The total prevalence rate of MetS was 9.3%. After adjusting for age, sex, educational levels, smoking, drinking, and exercise, MetS was associated with a lower odds ratio (OR) of having cognitive impairment (OR ¼ 0.443, 95% CI, 0.255e0.769) among the total population. Among men, a high triglyceride level was also associated with a lower OR of having cognitive impairment (OR ¼ 0.434, 95% CI, 0.191e0.989). Conclusion: MetS may be associated with better cognitive function among the oldest old. Among male nonagenarians and centenarians, high triglyceride level and systolic blood pressure, which are parts of MetS, are also associated with better cognitive function. Published by Elsevier Inc. on behalf of the American Medical Directors Association, Inc. As the population of the world ages, especially among devel- oping countries, understanding potentially modifiable risk factors of cognitive impairment will become more important. Metabolic syndrome (MetS), which includes a cluster of the risk factors obesity, hypertension, dyslipidemia, and insulin resistance, may be of special interest because of the increased prevalence with age. 1 Each individual risk factor has been shown to be associated with cognitive impairment. 2e5 There is also some evidence that the clustering of these risk factors is associated with cognitive impairment. 6,7 The association between some risk factors in MetS and cognitive dysfunction appear to vary with age. 8e10 However, the average age of each population in these studies was younger than 80 years. In recent years, several studies have reported that MetS increases the risk for development of cognitive impairment, 11,12 but other studies have failed to find an increased risk. 13 In this study, we aimed to examine the relationship between MetS and cognitive impairment among the oldest-old people using a cohort of Chinese individuals aged 90 to 108 years. Methods Participants were from the Project of Longevity and Aging in Dujiangyan. This cross-sectional study was performed in Du- jiangyan, which had a population of 2,311,709 people at the time of the study. Dujiangyan is located in southwest China outside the urban area of Chengdu. In April 2005, 870 people of the local Du- jiangyan population aged 90 years and older participated. The study protocol was approved by the Research Ethics Committee of Sichuan University. Informed consent was obtained from all participants (or their legal proxies). Trained personnel visited all study participants at their homes or at the community centers for data collection. Biological specimens were collected, and anthropometric measure- ments were done. The authors have no conflicts of interest to disclose. This work was supported by Discipline Construction Foundation of Sichuan University, grants from the project of Science and Technology Bureau of Sichuan Province (2006Z09-006-4), and Construction Fund for Subjects of West China Hospital of Sichuan University (XK05001). * Address correspondence to Birong Dong, MD, Department of Geriatrics, West China Hospital, Sichuan University, No. 37 Guoxuexiang, Wuhou District, Chengdu, China, 610041. E-mail address: birongdong@163.com (B. Dong). JAMDA journal homepage: www.jamda.com 1525-8610/$ - see front matter Published by Elsevier Inc. on behalf of the American Medical Directors Association, Inc. http://dx.doi.org/10.1016/j.jamda.2012.10.001 JAMDA 14 (2013) 105e108