Sodium serum levels in hypoalbuminemic adults at general medical wards

Hypoalbuminemia may cause interstitial edema and hemodilution, which we hypothesized may influence serum sodium levels. Our purpose was to compare serum sodium levels of hospitalized adults with or without hypoalbuminemia. All sodium and albumin serum levels of 142 adults hospitalized at general medical wards over a six-month period were searched at a University Hospital mainframe computer. Relevant laboratory data and clinical details were also registered. Hypoalbuminemia was defined by serum albumin concentration < 3.3 g/dl Fisher, Mann-Whitney, and Student's t tests were applied to compare groups with or without hypoalbuminemia. Ninety-nine patients, classified as hypoalbuminemic, had lower blood hemoglobin (10.68 +/- 2.62 vs. 13.54 +/- 2.41), and sodium (135.1 +/- 6.44 vs. 139.9 +/- 4.76 mEq/l) and albumin (2.74 +/- 0.35 vs. 3.58 +/- 0.28 g/dl) serum levels than non-hypoalbuminemic (n = 43). Pearson's coefficient showed a significant direct correlation between albumin and sodium serum levels (r = 0.40) and between serum albumin and blood hemoglobin concentration (r = 0.46). Our results suggest that hypoalbuminemic adults have lower serum sodium levels than those without hypoalbuminemia, a phenomenon that may be at least partially attributed to body water retention associated with acute phase response syndrome.