SAN DIEGO—Hyponatremia develops in 8% of patients with chronic kidney disease (CKD) overall, with the highest prevalence found in patients with CKD stage 5, Japanese researchers reported at Kidney Week 2015.
Masahiko Nagahama, MD, of St. Luke’s International Hospital in Tokyo, and colleagues studied 32,438 patients who visited an outpatient clinic. Of these, 9,388 met criteria for CKD, either an estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73 m2 or below or the presence of proteinuria. The prevalence of hyponatremia, defined as a serum sodium level of 135 mEq/L or less, varied according to CKD stage. It was 11.5%, 9.3%, 6.0%, 9.8%, 11%, and 15.1%, among patients with CKD stage 1, 2, 3a, 3b, 4, and 5, respectively. Among patients with moderate or severe CKD (stages 3, 4, and 5), diabetes was independently associated a significant 40% increased risk of hyponatremia, whereas use of renin-angiotensin-aldosterone system inhibitors was independently associated with a significant 32% decreased risk, in multivariate analysis.
In addition, compared with stage 3a CKD, stage 3b, 4, and 5 CKD were associated with a significant 1.7, 2.1, and 2.4 times increased odds of hyponatremia. Diabetes was associated with a significant 1.4 times increased odds.