Cardiovascular and Cognitive Health Study in Middle-Aged and Elderly Residents of Beijing(CCHS-Beijing): Design and Rationale.

The Cardiovascular and Cognitive Health Study (CCHS-Beijing) is a population-based study of cardiovascular disease (CVD) and cognitive impairment in adults aged 55 and older in Beijing. The main aims of the study are to investigate the prevalence rates of CVD, asymptomatic atherosclerosis, and cognitive impairment, as well as validate the risk factors related to the onset and development of CVD, Alzheimer's disease (AD) and mild cognitive impairment (MCI). The study was designed to detect the traditional and new risk factors in this age group. Participants were recruited randomly from residential regions in the greater Beijing municipality area based on the average levels of development in Beijing, China in 2012 (based on socioeconomic, demographic, and geographical characteristics). Thorough physical and laboratory examination were performed at baseline (also the cross-sectional survey) to identify the risk factors such as hypertension, dyslipidemia, diabetes, as well as newly defined risk factors like elevated homocysteine, high sensitivity C-reactive protein, and urine micro-albumin. Subclinical disease of the cerebral vasculature included atherosclerosis of carotid arteries, intracranial arteries, and retinal vessels. Subclinical cardiac diseases included left ventricular enlargement, arrhythmias, chamber hypertrophy and myocardial ischemia. Blood pressure was documented using the ankle-arm method. In addition, neuropsychological assessments were performed for all subjects aged 65 and above. Baseline evaluation began during the period August 2013 to December 2014. Follow-up examination will occur in 5 years. The initial and recurrent CVD, AD and MCI events will be verified and validated during the follow-up period.