Studies population
The target subjects of the present study were participants in the CHNS, which is an ongoing open, prospective household-based study conducted since 1989 to investigate health risk factors, nutritional status, sociological, demographic transformation, and health-related outcomes of the Chinese population 16 . The CHNS cohort includes new household formation and replacement communities and households; all household members are studied. Furthermore, in-depth community data are collected. Detailed information about the sampling procedure on the cohort has been reported elsewhere, and they are used jointly and separately in hundreds of studies 17,18,19 . This study was reviewed and authorized by Institutional Review Boards of the University of North Carolina at Chapel Hill and the National Institute of Nutrition and Food Safety, China Center for Disease Control and Prevention. Due to its excellent properties such as stratified random sampling, large sample, and panel data, CHNS data has become the basic data of this study. All methods were performed under their relevant guidelines and regulations. For investigating the association of dietary calcium, magnesium, and phosphorus with stroke, the data from CHNS surveys during 2004–2011 were used because it has provided more accurate dietary data since 2004. All the participants were restricted to those aged 45–79 years to ensure a relatively high stroke incidence, who had complete data about socio-economic, anthropometric, demographic, and three-day, 24 h dietary recalls. We excluded pregnant or lactating women, those who had implausible energy intakes (< 800 kilocalories (kcal) per day or > 6000 kcal for men and < 600 kcal or > 4000 kcal for women 20 ) or only participated in one survey in the four surveys from 2004 to 2011. Therefore, the current analysis consisted of 6411 participants who were available for the analysis. All subjects supplied their informed consent.
Weight loss intake
Investigation towards dieting intake is actually collected from the three successive 24-h diet remember on individual level combined with conversion process of cooking meals (such as for example oils and you may condiments) from the family level obtained from the eating catalog consider means over the same step 3-d course 21 . The typical each day consumption from calcium, magnesium, or phosphorus is actually computed because of the multiplying the fresh new consumption of each dining item from the mineral stuff out-of basic part measurements of a hundred g based on the Restaurants Composition Tables, upcoming summing the consumption amounts of nourishment throughout the every foodstuff.
Outcome aspect
The outcome of expose analysis was brand new experience stroke one occurred from inside the go after-upwards. Coronary arrest was outlined predicated on a personal-declaration away from prognosis from the a doctor in public places medical facilities over the condition height. The players should provide a certificate regarding heart attack medical diagnosis. Investigators need certainly to be sure this new patient’s medical diagnosis from research and you can query the questions ‘Provides a health care provider ever provided you the analysis out-of heart attack otherwise transient ischemic attack? How old was basically you after you was indeed earliest identified as having an excellent stroke podЕ‚Д…czenie lovoo or transient ischemic assault?’. For participants which considering contradictory answers from inside the go after-up, the first submitted coronary attack experience is actually implemented to restriction bear in mind bias.
Assessments off covariates
Questionnaire-centered interview amassed very first advice off professionals into the decades, gender, urbanization directory, degree, annual domestic money, smoking reputation, alcoholic beverages intake, physical exercise, body weight, blood pressure level, diabetes, myocardial infarction, and you can treatment play with. New urbanization list calculated from inside the individuals is founded on town where they alive. On area level, this new CHNS strategies the brand new urbanization list in the 12 proportions: populace thickness, economic craft, old-fashioned areas, modern areas, transportation structure, fitness, correspondence, housing, studies, assortment, wellness infrastructure, and you may personal services. The new in the-depth area contextual tips on the CHNS databases let us to create a sign of your significant measure off modernization level all of the 288 teams. Urbanization list and you may home income was divided into tertiles (low, middle, otherwise large). Educational attainment was categorized to the about three membership (primary, supplementary, otherwise college or university/university).