Blood Sodium Levels May Affect Cognition in Older Adults

A study published in the Clinical Journal of the American Society of Nephrology determined reduced levels of sodium in the blood have a connection with declines in cognitive function in older adults, reports Medical Xpress . The researchers analyzed information on 5,435 asymptomatic community-dwelling men older than 65 who were followed for an average of 4.6 years. A total of 100 men had serum levels indicating hyponatremia, and slightly lower sodium levels in the blood were associated with both cognitive impairment and declines in cognitive function over time. In comparison with men with sodium levels of 141-142 mmol/L, men with levels of 126-140 mmol/L were 30 percent more likely to have cognitive impairment at baseline and 3 percent more likely to experience cognitive decline over time. High serum sodium also was associated with cognitive decline over time. "Slightly lower sodium levels in the blood are likely to be unnoticed in clinical practice," says the University of Colorado's Dr. Kristen Nowak. "Because both slightly lower serum sodium levels and mild changes in cognitive function are common occurrences with advancing age, future research on this topic is important — including determining whether correcting lower sodium levels affects cognitive function."