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.