Frequent nocturnal urination in older men is associated with arterial stiffness: The Nagahama study.

Nocturia in older adults has been reported to be a risk factor for cardiovascular outcomes, and the stiffening of large arteries might be an underlying mechanism. To clarify the possible association between nocturia and arterial stiffness, we analyzed a dataset from the Japanese general population. Study participants consisted of 5928 community residents (mean age: 60.0 ± 11.8 years). The frequency of nocturnal urination was recorded for 1 week using a sleep diary. Arterial stiffness was assessed by brachial-to-ankle pulse wave velocity (baPWV). Sleep blood pressure was measured automatically at 0000, 0200, and 0400 hours by wearing a cuff on the upper arm during sleep. The mean baPWV was 1278 ± 227 cm/s. The frequency of nocturnal urination showed a linear positive association with baPWV (P < 0.001). The association between a sleep diary-based nocturnal urination frequency > 1.5 times/night (corresponding to a ≥ 2 times/night frequency obtained by the questionnaire) and baPWV remained significant after adjusting for major covariates, including office blood pressure (β = 0.051, P < 0.001) and sleep blood pressure (β = 0.040, P < 0.001). This association was more prominent in men (β = 0.069, P < 0.001) than in women (β = 0.023, P = 0.013), particularly in older (β = 0.068, P = 0.006) compared with younger (β = 0.029, P = 0.270) men. Frequent nocturnal urination was independently associated with baPWV in older men. Nocturia may be a marker for cardiovascular disease risks that cannot be assessed by conventional risk factors such as blood pressure.