Smoking and prevalence of nocturia in Japanese patients with type 2 diabetes mellitus: a post-hoc analysis of The Dogo Study

AimsNo evidence exists regarding the association between smoking status and nocturia among patients with type 2 diabetes mellitus. We evaluated this association among Japanese patients with type 2 diabetes mellitus by post-hoc analysis. MethodsStudy subjects were 817 Japanese patients with type 2 diabetes mellitus. Study subjects were considered to have nocturia if they answered once or more to the question: Within one week, how many times do you typically wake up to urinate from sleeping at night until waking in the morning? We used the following three outcomes: (1) nocturia was 1 voids per night; (2) moderate nocturia was 2 voids per night; and (3) severe nocturia was 3 voids per night. Adjustments were made for age, sex, body mass index, hypertension, dyslipidemia, stroke, glycated hemoglobin, current drinking, use of anti-hypertensive agent, use of insulin, use of oral anti-hyperglycemic agent, and diabetic retinopathy. ResultsThe prevalence values of one void per night, two voids per night, and three or more voids per night were 39.5%, 27.1%, and 14.8%, respectively. Current smoking was independently inversely associated with severe nocturia compared with never or former smoking; the adjusted PR was 0.47 (95%CI: 0.25-0.89). Among the 443 patients who had ever smoked, compared with former smoking, current smoking was independently inversely related to severe nocturia; the adjusted PR was 0.44 (95%CI: 0.24-0.82). ConclusionsIn Japanese patients with type 2 diabetes mellitus, current smoking may be independently inversely associated with severe nocturia.