Study Sees Link Between Low Salt Levels, Fracture Risk in Older Adults

SATURDAY Nov. 20, 2010 -- New research links lower-than-normal levels of sodium (salt) in the blood to a higher risk of broken bones and falls in older adults.

Even mildly decreased levels of sodium can cause problems, the researchers contend.

"Screening for a low sodium concentration in the blood, and treating it when present, may be a new strategy to prevent fractures," study co-author Dr. Ewout J. Hoorn, of Erasmus Medical Center in Rotterdam, the Netherlands, said in a news release from the American Society of Nephrology.

There's still a mystery: There doesn't appear to be a link between osteoporosis and low sodium levels, known as hyponatremia, so it's not clear why lower sodium levels may lead to more fractures and falls, the study authors said.

The researchers examined the medical records for six years of more than 5,200 Dutch people over the age of 55. The study authors wanted to confirm findings in recent research that linked low sodium to falls, broken bones and osteoporosis, Hoorn said.

About 8 percent of the participants had low sodium levels, which often develop when the kidneys hold too much water. The 8 percent were also more likely to have diabetes and use diuretics (water pills).

About a quarter of the people with low sodium levels had falls, compared to 16 percent of the others in the study, and their risk of vertebral/vertebral compression fractures was 61 percent higher. The risk of non-spinal fractures, such as broken hips, was 39 percent higher.

Those with low sodium were also 21 percent more likely to die during the six-year period.

"Although the complications of hyponatremia are well-recognized in hospitalized patients, this is one of the first studies to show that mild hyponatremia also has important complications in the general population," Hoorn said.

More research is needed to clarify the apparent link between low sodium levels and increased fracture risk. In the interim, "Screening older adults for and treatment of hyponatremia may be an important new strategy to prevent fractures," Hoorn said.

The study findings were to be presented Friday at the American Society of Nephrology's annual meeting, in Denver.

While the study found an association between low salt levels and risk of fractures, it did not prove a cause-and-effect. And research presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

More information

For more on kidney disease visit the U.S. National Library of Medicine.

Posted: November 2010


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