Nocturia: The Complex Role of the Heart, Kidneys, and Bladder

We review the role of the heart, kidneys, and bladder in the pathophysiology of nocturia and nocturnal polyuria. Lower urinary tract symptoms such as nocturia have often been associated with lower urinary tract dysfunction. It is known that the bladder contributes to nocturia in the case of low functional capacity, urgency, and detrusor overactivity. Heart diseases, especially arterial hypertension and congestive heart failure, are closely related to nocturnal polyuria. The main mechanisms include renal hyperfiltration and elevated atrial natriuretic peptide. A number of drugs frequently used in cardiovascular disorders are implicated in nocturia; diuretics, calcium channel blockers, and β-blockers induce nocturnal polyuria and thus nocturia, whereas alpha-blockers improve nocturia. Among the different forms of hypertension, nondipping arterial hypertension has been associated with a higher risk of nocturnal polyuria. Besides the role of the kidneys in nocturia linked to arterial hypertension, chronic kidney disease is an independent predictor of nocturia through an osmotic diuresis mechanism. Some evidence suggests a close relationship between the heart (nondipping arterial hypertension), kidneys (chronic kidney disease), and nocturia/nocturnal polyuria. These complex interactions between the heart, kidneys, and bladder warrant a multidisciplinary approach in patients with nocturia. PATIENT SUMMARY: We review the different mechanisms that lead to nocturia and nocturnal polyuria. The complex interactions between the heart, the kidneys, and the bladder warrant a multidisciplinary approach in patients with nocturia. Careful investigation of the cause of nocturia can improve its management.