Low sodium may increase fracture risk in elderly
MedWire News: Mild hyponatremia - low sodium in the blood - may be a risk factor for vertebral and non-vertebral fractures in elderly men and women, researchers reported at the 13th European Congress of Endocrinology in Rotterdam, The Netherlands.
If the link is proven, the team recommends that "screening for hyponatremia should be advised for elderly patients with fractures."
Study author Carola Zillikens (Erasmus MC, Rotterdam) explained that although recent studies suggest that mild hyponatremia - which does not usually cause symptoms or require treatment - is associated with fractures, prospective studies are lacking.
The researchers therefore used data on 5208 elderly men and women participating in the prospective, population-based Rotterdam Study to investigate whether the condition is associated with fractures, falls, and/or bone mineral density (BMD).
All participants had their serum sodium level and BMD measured at baseline.
Zillikens reported that 399 (7.7%) patients were hyponatremic at study entry, with a mean sodium level of 133.4 mmol/l.
Hyponatremia was not associated with BMD, but was associated with a significant 39% increased risk for incident non-vertebral fractures during a 7.4-year follow-up period, after adjustment for age, gender, body mass index, disability index, use of diuretics or psycholeptics, and prevalent diabetes.
Participants with hyponatremia were also 1.78 times more likely to have a vertebral fracture at baseline, but not at follow-up, than those without the condition.
Of note, people with hyponatremia were significantly more likely to have recently suffered a fall (23.8% vs 16.4%) than those with normal sodium levels, but this did not affect their likelihood of experiencing a fracture.
"Osteoporosis and resulting fractures are a huge burden on national health systems and result in decreased quality of life for millions of patients. Our research shows that patients with hyponatremia are significantly more likely to suffer a fracture than patients without this condition," said Zillikens.
"Our next step is to see if these findings can be replicated in independent populations. If we can do this, it may be advisable to implement a screening program for hyponatremia in elderly patients that present with fractures. Physicians may consider treatment of mild hyponatremia if future studies show that treatment of mild hyponatremia decreases fracture risk," she concluded.
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By Laura Dean