The effects of lifestyle factors on the incidence of nocturia.

PURPOSE

Cross-sectional studies have shown an association between obesity and nocturia but controversial findings on the relationship between smoking, alcohol and coffee consumption, and nocturia. Prospective studies of the role of lifestyle factors in individuals with nocturia are scarce. We investigated the effects of lifestyle factors on the incidence of nocturia.

MATERIALS AND METHODS

The target population consisted of men who were 50, 60 or 70 years old and residing in Tampere in 1994. A questionnaire was mailed to 3,143 randomly selected men in 1994 and the survey was repeated in 1999 with the 2,837 who were still eligible. The followup sample consisted of 1,580 men with information on nocturia at baseline and 5-year followup. Nocturia was assessed by the Danish Prostate Symptoms Score 1 questionnaire and graded as mild--1 or 2, moderate--3 or 4 and severe--5 or more nightly voids.

RESULTS

Higher body mass index at baseline was associated with an increased incidence of nocturia. Obese men were at 1.6 times (95% CI 1.1-2.4) higher risk for mild nocturia and at 2.3 times (95% CI 1.1-4.7) higher risk for moderate or severe nocturia compared with men who had a normal body mass index. Men who consumed less than 150 gm alcohol per week were at lower risk for moderate or severe nocturia than abstainers (adjusted incidence rate ratio 0.4, 95% CI 0.2-0.8). No statistically significant associations were found for smoking and coffee consumption. The frequency of nocturia at baseline did not increase the incidence of obesity at followup.

CONCLUSIONS

Our findings suggest that obesity increases the risk of nocturia. The link between other lifestyle factors and nocturia is weak or absent.