Change of blood viscosity and urinary frequency by high water intake

Abstract

Physicians recommend a high water intake to prevent cerebral infarction by decreasing blood viscosity. However, there is no evidence that high water intake decreases viscosity, although it increases urinary frequency. Therefore, we investigated the change of blood viscosity and urinary frequency by high water intake. We examined the change of blood viscosity after acute water intake, the circadian rhythm of blood viscosity, and the change of early morning blood viscosity and urinary frequency after high water intake for 1 week in healthy volunteers aged 31-75 years. Blood viscosity decreased transiently by acute water intake, but remained within the range of its circadian rhythm. Morning blood viscosity did not alter by high water intake for 1 week, although urinary frequency increased. Because excessive water intake increases urinary frequency without decreasing blood viscosity, a high water intake should not be recommended in persons with urinary frequency.

Relationship between Urological Disease and Inferior Vena Cava Reflux on Color Doppler Ultrasonography

“…Therefore, it is possible that the diuretic effect of these herbal medicines improves the symptoms of diseases associated with pelvic congestion. When urological diseases associated with pelvic congestion, such as chronic prostatitis, stress incontinence, urethral syndrome, and cystocele, are diagnosed, lifestyle modification is necessary such as avoidance of excessive water intake 20 and of standing or sitting for a long time.…”

Association between Water Intake, Chronic Kidney Disease, and Cardiovascular Disease: A Cross-Sectional Analysis of NHANES Data

“…There is some evidence that dehydration might contribute to increased blood viscosity [60,61], a known risk factor for ischemic heart disease and stroke [62,63]. However, several interventions have failed to reduce blood viscosity with greater fluid intake [60,61,64,65] — possibly because a benefit of greater water intake may not be realized in patients who are adequately hydrated, as appeared to be the case in one trial, where the baseline urine volume of patients was ∼1.6 l/day [65]. Few studies have evaluated the direct effect of water intake on cardiovascular outcomes, and these have produced equivocal results.…”

Clinical guidelines for nocturia

“…Because excessive nocturnal consumption of water, alcohol and caffeine are reported to be factors in nocturnal polyuria, patients should be instructed to avoid such consumption 11–13 . In particular, excessive water intake makes it necessary for the body to regulate its water intake balance 11 .…”

“…Particularly in the elderly, dehydration is reported to be a factor in the onset of cerebral infarction. However, there is no evidence that excessive water intake has any ‘blood‐thinning’ preventative effect against cerebral infarction, and one report has shown no observable changes in blood viscosity after water intake (Level V) 12 …”