Prevalences
The prevalences for each of the electrolyte disorders are
shown in Table 2. Hyponatremia and hypernatremia were
the most common electrolyte disorders, whereas hyperkalemia
was relatively uncommon. Significant interactions between
increasing age and the prevalence of hyponatremia
and hyperkalemia were found. Compared with normonatremic
subjects, subjects with hyponatremia (73.4 10.3 years
vs 70 8.9 years, P .001) and hyperkalemia (80.5 7.3
years vs 70.29.1 years, P.001) were older compared with
controls. Hypokalemia was approximately 2 times more often
present in women (3.5% vs 1.5%, P .001). Overall, 776
subjects (15.0%) had at least 1 electrolyte disorder.