2.4 | Measurements
Blood pressure (both systolic and diastolic values) was measured by a trained clinician while the participants were seated. Blood samples were obtained after at least 8 hours of fasting. The levels of glucose, total cholesterol, triglycerides (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and creatinine were measured. Estimated glomerular filtration rate (eGFR) was calculated using the equation from the Modification of Diet in Renal Disease study: eGFR=186.3×serum creatinine−1.154×age−0.203×0.742 (for women).
Information about lifestyle factors, including smoking status, alcohol intake status, exercise frequency, and past medical history (history of hypertension, dyslipidemia, impaired fasting glucose [IFG], and chronic kidney disease [CKD]) was obtained using a standardized self-assessment questionnaire. Drinking status was divided into three categories: nondrinker, mild drinker, and heavy drinker; heavy alcohol consumption was defined as drinking more than 30 g of alcohol per day. Regular physical activity was defined as more than 30 minutes of moderate physical activity performed at least five times per week, or more than 20 minutes of strenuous physical activity performed at least three times per week. Low income was defined as being within the lowest 20% of the total population based on monthly income.