Background: Hyponatremia is associated with unfavorable outcomes in many cases. The mainstay of hyponatremia treatment depends on its symptoms and etiology. However, etiologies, clinical manifestations, and factors associated with severe symptomatic hyponatremia have been rarely reported.

Objective: To analyze and report etiologies, clinical manifestations, and factors associated with severe symptomatic hyponatremia.

Materials and Methods: In the present cross-sectional study, the authors enrolled hospitalized patients with hyponatremia who had consulted a nephrologist between October 1, 2017, and October 31, 2018. Their baseline characteristics and clinical manifestations were recorded. Etiologies were confirmed by the attending nephrology staff. Factors associated with severe symptomatic hyponatremia were evaluated using logistic regression analysis.

Results: One hundred patients were included in this study. The syndrome of inappropriate antidiuresis (SIAD), hypovolemia, and hydrochlorothiazide use were the leading hyponatremia etiologies. Hyponatremia etiologies differed between patients with community-acquired hyponatremia (n=50) and those with hospital-associated hyponatremia (n=50). Patients with communityacquired hyponatremia were older, presented with a higher frequency of severe symptomatic hyponatremia, and showed lower SNa-levels. Low SNa-levels were significantly associated with severe symptomatic hyponatremia (p=0.014).

Conclusion: Hyponatremia remains an important health problem. SIAD, hypovolemia, and hydrochlorothiazide use are among the leading etiologies of hyponatremia. Low SNa-levels are associated with severe symptomatic hyponatremia; thus, physicians should pay close attention to low SNa-levels in hospitalized patients.

Keywords: Hyponatremia, Symptomatic Hyponatremia, Community-acquired hyponatremia, Hospital-associated hyponatremia

DOI: doi.org/10.35755/jmedassocthai.2020.05.10937

Received 17 Dec 2019 | Revised 17 Feb 2020 | Accepted 19 Feb 2020