Prevalence and associated risk factors of nocturia and subsequent mortality in 1,301 patients with type 2 diabetes

To evaluate the correlates of nocturia and subsequent mortality in patients with type 2 diabetes mellitus (T2DM). A self-administered questionnaire containing overactive bladder symptom score was obtained from subjects with T2DM. Nocturia and severe nocturia were defined as rising a parts per thousand yen2 or a parts per thousand yen3 per night to void, respectively. Patient characteristics and diabetes-related complications to risk of nocturia were evaluated. Of 1,301 consecutive subjects, 59.6 and 25.3 % reported having nocturia and severe nocturia, respectively. The presence and severity of nocturia increased with age and overactive bladder (OAB). The presence of OAB was 28.8 % in patients with nocturia and was significantly associated with nocturia (OR 2.26) after adjustment for age and duration of DM. The presence of stroke, calcium channel blocker use, hypertension, waist circumference greater than standard, albuminuria, and higher serum creatinine level, and high-sensitivity C-reactive protein was associated with nocturia and severe nocturia after adjustment for age, duration of DM, and the presence of OAB. Higher estimated glomerular filtration rate, hemoglobin, serum albumin, and male gender were less likely to have nocturia (OR < 1). Severe nocturia increased mortality (OR 1.93) independent of age and DM duration and has a higher mortality rate compared to those without severe nocturia (6.1 vs. 2.4 %, P = 0.001) in 2.5 years follow-up. While OAB is an important predictor of nocturia in T2DM patients, systemic issues, including stroke, hypertension, obesity, and chronic kidney disease, have further impact on nocturia independent of OAB. Severe nocturia is a marker for increased mortality.