From Clinical Endocrinology News, August 2014, http://www.clinicalendocrinologynews.com/home/article/hyponatremia-linked-to-osteoporosis-fragility-fractures/6cf3771d27ad1965216e185e730634c3.html, Dr. Verbalis and co-researchers reported on their retrospective database study that linked low serum sodium (hyponatremia) with osteoporosis and fragility fractures. The findings were reported at a poster session at the International Congress of the Endocrine Society this summer. In studying over 30,000 patients diagnosed with osteoporosis with an equal number of matched controls, chronic hyponatremia (at least two sodium values below 135mmol/L at least one year apart) were far more likely to be later diagnosed with osteoporosis, with an adjusted odds ratio of 3.99. More recent hyponatremia (at least one sodium value below 135mmol/L in the previous 30 days) was associated with an odds ratio of 3.08. In contrast, this compares to an odds ratio in those taking glucocorticoids, a well established osteoporosis risk factor, of only 1.4. Those with a previous diagnosis of osteoporosis were found to have an odds ratio of 1.8.
The findings are most remarkable implying that low serum sodium is strongly associated with fracture risk in the elderly. It was suggested by the researchers that “those with hyponatremia beyond a single event should be evaluated for their bone density and fracture risk,” said Dr. Joseph Verbalis, chief of the division on endocrinology and metabolism at Georgetown University. Dr. Verbalis went on to say, “..we speculate that early treatment of hyponatremia will prevent progression of bone disease and decrease fracture risk.” Suggested causes in the elderly were salt-restriction, sodium-depleting drugs such as thiazide diuretics, or those that cause syndrome of inappropriate anti-diuretic hormone (SIADH). One must also consider SSRIs as a contributing factor.