Hyponatremia Hospitalizations Up With Rising Ambient Temps

TUESDAY, March 15, 2022 (HealthDay News) -- The incidence of hyponatremia hospitalizations is increased on the hottest days, with the greatest risk seen for women and the elderly, according to a study published online Feb. 22 in the Journal of Clinical Endocrinology & Metabolism.

Buster Mannheimer, Ph.D., from the Karolinska Institutet in Stockholm, and colleagues examined the influence of ambient temperature on hyponatremia in the Swedish population. All patients hospitalized with a first-ever principal diagnosis of hyponatremia were identified between October 2005 and December 2014. The incidence rates of hyponatremia were calculated at a given temperature, in increments of 1 degree Celsius.

The researchers found that from −10 to 10 degrees Celsius, the incidence of hyponatremia was stable at 0.3 per million person-days but increased rapidly at 24-hour mean temperatures greater than 15 degrees Celsius. At the highest recorded temperature, there were 1.96 hospitalizations per million person-days. The greatest risk was seen for women and the elderly; on the hottest days, the incidence was 30 hospitalizations per million person-days in individuals aged 80 years or older, corresponding to a 15-fold increase in incidence relative to cool days. An increase in the incidence of hyponatremia by 6.3 and 13.9 percent, respectively, is expected with a future increase of 1 or 2 degrees Celsius in mean temperature.

"We believe these estimates are quite conservative seeing as we didn’t account for secondary diagnoses of hyponatremia, extreme weather events or an aging population," a coauthor said in a statement. "Without adaptive measures, this suggests that over the next decades, rising global temperatures alone will increase the burden of hyponatremia on health care systems."

Two authors disclosed financial ties to Otsuka Pharma Scandinavia; the study was funded by Cebix Incorporated.

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