BMC Public Health Research article Sleep quality in middle-aged and elderly Chinese: distribution, associated factors and associations with cardio-metabolic risk factors Nazanin Haseli-Mashhadi1, Tony Dadd1, An Pan2, Zhijie Yu2, Xu Lin2 and Oscar H Franco*1,3 BioMed Central Open Access Address: 1Unilever R&D, Colworth Science Park, Sharnbrook, Bedfordshire, MK441LQ, UK, 2Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Graduate School of the Chinese Academy of Sciences, Shanghai, PR China and 3Health Sciences Research Institute, Warwick Medical School, The University of Warwick, Coventry, CV47AL, UK Email: Nazanin Haseli-Mashhadi - hasseli57@yahoo.com; Tony Dadd - tony.dadd@unilever.com; An Pan - apan@sibs.ac.cn; Zhijie Yu - zjyu@sibs.ac.cn; Xu Lin - xlin@sibs.ac.cn; Oscar H Franco* - o.H.Franco@warwick.ac.uk * Corresponding author Published: 9 May 2009 BMC Public Health 2009, 9:130 doi:10.1186/1471-2458-9-130 This article is available from: http://www.biomedcentral.com/1471-2458/9/130 Received: 22 December 2008 Accepted: 9 May 2009 © 2009 Haseli-Mashhadi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Poor sleep quality has been associated with increased risk of heart disease, diabetes and mortality. However, limited information exists on the distribution and determinants of sleep quality and its associations with cardio-metabolic risk factors in Chinese populations. We aimed to evaluate this in the current study. Methods: A cross-sectional survey conducted in 2005 of 1,458 men and 1,831 women aged 50– 70 years from urban and rural areas of Beijing and Shanghai. Using a questionnaire, sleep quality was measured in levels of well, common and poor. Comprehensive measures of socio-demographical and health factors and biomarkers of cardio-metabolic disease were recorded. These were evaluated in association with sleep quality using logistic regression models. Results: Half of the population reported good sleep quality. After adjusting for potential confounders, women and Beijing residents had almost half the probability to report good sleep quality. Good physical and mental health (good levels of self-rated health (OR 2.48; 95%CI 2.08 to 2.96) and no depression (OR 4.05; 95%CI 3.12 to 5.26)) related to an increased chance of reporting good sleep quality, whereas short sleep duration (<7 hrs OR 0.10; 95%CI 0.07 to 0.14)) decreased it substantially. There were significant associations between levels of sleep quality and concentrations of plasma insulin, total and LDL cholesterol, and index of insulin resistance. Conclusion: Levels of good sleep quality in middle-age and elderly Chinese were low. Gender, geographical location, self-rated health, depression and sleep quantity were major factors associated with sleep quality. Prospective studies are required to distil the factors that determine sleep quality and the effects that sleep patterns exert on cardio-metabolic health. Page 1 of 11 (page number not for citation purposes)