Information on potential covariates was collected in 2006 and updated every 2 years thereafter, as detailed elsewhere (11 (link),12 ,16 (link),20 (link)). In brief, information on age, sex, smoking, alcohol intake, salt intake, physical activity, average monthly income, education level, and past self-reported medical history (e.g., hypertension, diabetes, and active treatment such as hypoglycemic agents, antihypertensive agents, lipid-lowering agents, and aspirin) was collected via questionnaire. Assessment of alcohol intake was determined as follows: light drinker, 0.1–0.4 servings/day for women and 0.1–0.9 servings/day for men; moderate drinker, 0.5–1.5 servings/day for women and 1–2 serving/day for men; heavy drinker, >1.5 servings/day for women and >2 serving/day for men; based on 15 g of alcohol per day. Height, weight, and blood pressure were measured by trained field workers (i.e., nurses) during the surveys. BMI was calculated as weight in kilograms divided by height in meters squared. Total cholesterol, triglycerides, HDL cholesterol (HDL-c), LDL cholesterol (LDL-c), creatinine, and hs-CRP were assessed by auto analyzer (Hitachi 747; Hitachi, Tokyo, Japan) at the central laboratory of Kailuan hospital. Estimated glomerular filtration rate (eGFR) was calculated by the Chronic Kidney Disease Epidemiology Collaboration creatinine equation (21 (link)).