Hyponatremia in the outpatient setting: clinical characteristics, risk factors, and outcome.
OBJECTIVE
Hyponatremia is a common disorder and hyponatremia in the outpatient setting is not extensively studied. Our aim was to investigate the characteristics of hyponatremia in ambulatory patients.


METHODS
Seventy-six adult outpatients with hyponatremia were enrolled in this prospective study. Demographic features, presenting symptoms and signs, associating morbidities, medications, laboratory findings, mortalities, and length of hospital stay, were recorded.


RESULTS
Mean age was 74.7 ± 12.7 years, and 52 (68.4 %) were female whereas 24 (31.6 %) were male. Mean sodium concentration was 123.6 ± 6.6 mEq/L. Leading cause was thiazide diuretic use (n = 37, 48.7 %) and approximately half of the patients (n = 40, 52.6 %) had a multifactorial etiology. Severe hyponatremia (sodium < 125 mEq/L) was identified in 37 (48.7 %). Thiazide diuretic use, vomiting, and apathy were independent predictors of severe hyponatremia. Eight (10.5 %) patients had a mortal course. A relatively younger age, male gender, presenting sign of lethargy, associating morbidities of malignancy, chronic liver disease, and hypoalbuminemia were risk factors for mortality.


CONCLUSIONS
Hyponatremia is prevalent among elderly, especially in women and with thiazide diuretics. Apart from the trend toward sodium depletion observed in healthy elderly which occurs due to changes in the tubular handling of sodium, a multifactorial etiology including thiazides seems to predict the occurrence and the severity of hyponatremia. Hyponatremia may be a significant cause of mortality in seniors. A relatively younger age, male gender, association of cirrhosis, malignancy, and hypoalbuminemia predict mortality. In elderly outpatients, identification of the risk factors for hyponatremia and close monitoring are imperative to reduce the related mortality and morbidity.
Department of Internal Medicine, Ufuk University School of Medicine, Ankara, Turkey.
Vildan
V
Tasdemir
Department of Internal Medicine, Ufuk University School of Medicine, Ankara, Turkey.
Ali Kemal
AK
Oguz
Department of Internal Medicine, Ufuk University School of Medicine, Ankara, Turkey.
Irmak
I
Sayın
Division of Nephrology, Department of Internal Medicine, Ufuk University School of Medicine, Dr. Rıdvan Ege Hospital, Konya Bulvarı No: 86-88, Balgat, Çankaya, 06520, Ankara, Turkey. ihsanerg@yahoo.com.
Ihsan
I
Ergun
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D057565:Apathy; D015897:Comorbidity; D004232:Diuretics / Q000009:adverse effects; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D012964:Sodium / Q000097:blood; D049971:Thiazides / Q000009:adverse effects
D004232:Diuretics; D049971:Thiazides; D012964:Sodium
Elderly; Hypoalbuminemia; Hyponatremia; Mortality; Outpatient; Thiazides