Study: Age is only significant predictor of nocturia

Paris-While many characteristics and conditions are associated with nocturia, patient age is the only factor that can significantly be linked with its development, Dutch researchers report.

"Nocturia is a very prevalent and bothersome condition, which is associated with a number of conditions in older men. Although numerous studies have been published on the association of nocturia with BPH or cardiac symptoms, there is a paucity of data on what actually predicts its development," said first author Boris Van Doorn, MD, a urology resident at University Medical Center Utrecht, Utrecht, the Netherlands, in his presentation at the 2012 European Association of Urology annual congress in Paris.

Dr. Van Doorn and colleagues analyzed the database of a population-based cohort that included 1,688 men aged 50 to 78 years. Men without nocturia at baseline and no exclusion criteria (radical prostatectomy, transurethral surgery, or bladder or prostate cancer) were selected.

At baseline, 1,597 men completed the FVC. Of these, 133 men met the exclusion criteria, 342 were excluded because of missing sleep-hours, and 386 were excluded due to nocturia (34.4%), resulting in a target population of 736 men. After a follow-up of 2.1 years, 341 men were excluded because they did not void during the night or within the first hour of rising, did not complete an FVC, or did not follow up.

Of the remaining 395 men in the study (median age, 59.8 years), univariable and multivariable analysis of their baseline characteristics showed no significant differences. Variables with an association (p<.25) were selected to create a multivariable logistic regression model. After a manual backward selection procedure, a final model was created with only significant association (p<.05).

Alcohol intake may have protective effect

"After 2.1 years, we checked whether the patients developed nocturia and which characteristics men who had developed nocturia had in common. The incidence rate at this time was 24.8%. The univariable and multivariable logistic regression models revealed that only age and alcohol intake were significantly related to the development of nocturia in older men in the open population," observed Dr. Van Doorn, who worked on the study with J. L. H. Ruud Bosch, MD, PhD, and colleagues. "Interestingly, alcohol intake had a protective effect against nocturia development."

Predictors of nocturia are easily missed, in particular because of their varied nature, according to Kari A.O. Tikkinen, MD, PhD, of Helsinki University Central Hospital, Helsinki, Finland, who argued that there have been studies showing a relationship between depression and nocturia, as well as between hypertension and nocturia, among others.

"The biggest issue here is that most men with cardiac symptoms, diabetes, or men using diuretics actually often already have nocturia, and so are excluded from this particular analysis. It is hard to get significant results because in the selected population for this analysis, only few actually have these conditions," Dr. Van Doorn explained.

"Nocturia is associated with a number of factors, among which have been counted behavioral, hormonal, medical treatment, heart, pulmonary, bladder, and prostate disease, as well as metabolic syndrome," observed session co-chair Matthias Oelke, MD, of the department of urology, Hannover Medical School, Hannover, Germany.

The study was supported by an unrestricted educational grant from Ferring Pharmaceuticals.