Association between urinary sodium excretion and coronary heart disease in hospitalized elderly patients in China

OBJECTIVE: This study was performed to evaluate the association between urinary sodium excretion and coronary heart disease (CHD) in hospitalized elderly patients in China. METHODS: The 24-h urinary excretion specimens of 541 patients were collected, and the serum creatinine concentration and urinary sodium/potassium ratio were measured. Associations were explored by multivariate logistic regression analysis. RESULTS: The mean 24-h urinary sodium excretion was 200.4 mmol, corresponding to 11.7 g of salt intake. Both of these values were higher in men than in women. The salt intake of 80- to 89-year-old patients was significantly lower than that of 70- to 79-year-old patients. The 24-h urinary sodium excretion and spot urine Na/K ratios were significantly higher in overweight/obese and hypertensive patients. The 24-h urinary sodium excretion of men who smoked was significantly higher than that of women. The spot urine Na/K ratio was significantly higher in patients with cerebral thrombosis. The urinary Na/K ratio, smoking status, and hypertension were independent risk factors for CHD. CONCLUSIONS: This cross-sectional survey suggests that the Na/K ratio may better represent salt loading than Na excretion alone in studying the association between sodium intake and CHD. There was no association between sodium and CHD prevalence.