Correlates for nocturia: a review of epidemiological studies.

Traditionally, nocturia was considered to be one of the symptoms of prostatism. However, this symptom has unusual characteristics compared with other lower urinary tract symptoms; for example, there is only a mild benefit for nocturia from treatment for benign prostatic hyperplasia. In the past decade, nocturia has been investigated as a separate symptom in epidemiological studies. These types of studies have shown various correlates for nocturia other than benign prostatic hyperplasia, as well as the prevalence of this symptom. These correlates include age, race/ethnicity, medical problems (such as hypertension, diabetes and stroke) psychological aspects, tasting habits, quality of life and even mortality. The cause-and-effect associations are not always obvious between nocturia and its correlates. In the present article, the author attempts to comprehensively review the correlates for nocturia shown by epidemiological studies.