Women are at higher risk than men for diuretic-induced hyponatremia resulting in hospital admission, according to a recent study published in Pharmacoepidemiology & Drug Safety.
In a case-control study that included 886,935 diuretic users (524,683 women and 362,252 men) in The Netherlands, investigators found that women had significant 2.7-fold higher odds of hospitalization due to diuretic-induced hyponatremia compared with men after adjusting for potential confounders. The higher risk for women vs men was present regardless of diuretic type.
“The underlying mechanism that could cause the higher risk of hyponatremia in women using diuretics is not fully understood,” Linda C. Hendriksen of Erasmus University Medical Center in Rotterdam, and colleagues wrote. “There might be sex differences in vasopressin regulation and in the amount and activity of several receptors and transporters.”
Hendriksen and colleagues used 2005-2017 data from the PHARMO Data Network, which is a population-based network of electronic health care databases for the study. Of the cohort, 1257 women and 332 men had a first hospital admission for hyponatremia from January 1, 2005 to December 31, 2017. The investigators matched these patients to a control group of 10,639 women and 5223 men who used diuretics but were not hospitalized with hyponatremia.
Strengths of the study included the use of a large population-based database and the availability of individual patient data on hospital admissions and drug dispensing, the authors noted. “With this information, we were able to adjust for age, number of diuretics and other hyponatremia-inducing drugs, chronic disease score, daily dose and the duration of use of the diuretic, factors that have not previously been studied in hyponatremia-related hospital admissions.”
The investigators pointed out, however, that they had limited availability of other possible confounders. In addition, patients’ sodium levels were not available. “Patients with a low sodium level could have been missed when hyponatremia was not documented by the physician or not coded at discharge.”
Hendriksen LC, van der Linden PD, Herings RMC, Stricker BH, Visser LE. Women on diuretics have a higher risk of hospital admission because of hyponatremia than men. Pharmacoepidemiol Drug Saf. 2023:1-8. Published online January 12, 2023. doi:10.1002/pds.5592