Posted on Dec 19, 2011, 6 a.m.
Among people with increased cardiovascular risk, sodium intake that is too high or too low appears to be associated with an elevated risk of cardiovascular events.
Some studies suggest a relationship between sodium and potassium intake and cardiovascular risk – especially in patients with cardiovascular disease. Martin J. O'Donnell, from McMaster University (Canada), and colleagues performed an analysis on 28,880 patients, ages 55 years and older, with either established cardiovascular disease or high-risk diabetes, enrolled in the ONTARGET and TRANSCEND trials. Intake of both sodium and potassium was estimated from baseline urinary samples. Through a median follow-up of 56 months, cardiovascular death, myocardial infarction, stroke, or hospitalization for congestive heart failure occurred in 16.4% of the patients. As compared with patients who had an estimated sodium intake of 4,000 to 5,999 mg/day, those who consumed more than 8,000 mg/day had greater risks of the composite outcome and all of the individual components. In addition, an intake of 7,000 to 8,000 mg/day was associated with a 53% greater risk of cardiovascular death. As well, lower sodium intake also was associated with poor outcomes. As compared with the reference group, patients consuming less than 3,000 mg/day had elevated risks of the composite outcome and cardiovascular death. An intake of 2,000 to 2,999 mg/day was associated with a greater risk of being admitted for congestive heart failure. The study authors summarize their findings as: ”Compared with baseline sodium excretion of 4 to 5.99 g per day, sodium excretion of greater than 7 g per day was associated with an increased risk of all [cardiovascular] events, and a sodium excretion of less than 3 g per day was associated with increased risk of [cardiovascular] mortality and hospitalization for [congestive heart failure].”
Martin J. O'Donnell, Salim Yusuf, Andrew Mente, Peggy Gao, Johannes F. Mann, Koon Teo, et al. “Urinary Sodium and Potassium Excretion and Risk of Cardiovascular Events.” JAMA, 2011;306(20):2229-2238.