The mild hyponatremia group had significantly older age (median [interquartile range], 82.0 [76.0–84.0] vs 79.0 [75.0–83.0] years), fewer women (48.0% vs 63.1%), higher prevalence of history of diabetes (48.0% vs 36.1%), higher antiepileptic use (2.7% vs 0.4%), higher SSRI or SNRI use (6.7% vs 1.8%), higher benzodiazepine use (16.0% vs 8.7%), higher potassium (4.4 [4.1–4.6] vs 4.2 [2.9–4.4] mEq/L), higher CRP (0.07 [0.04–0.2] vs 0.05 [0.03–0.1] mg/dL), and higher frequency of anemia (13.3% vs 6.7%) and hypothyroidism (2.7% vs 0.3%) compared with the normonatremia group. Here, CRP is linked to anemia.