From the Guidelines
Nocturia occurs more at night due to a combination of physiological factors, including the return of fluid to circulation when lying down, disrupted circadian rhythms, and underlying medical conditions, as highlighted in the most recent study 1.
Causes of Nocturia
The causes of nocturia can be multifactorial, including:
- Overactive bladder
- Urinary tract infections
- Enlarged prostate in men
- Diabetes
- Heart failure
- Sleep apnea
- Certain medications like diuretics
- Lifestyle factors such as excessive evening fluid intake, especially caffeine or alcohol
Physiological Mechanisms
During the day, gravity helps keep fluid in the lower extremities, but when lying down at night, this fluid returns to circulation and increases urine production. Additionally, the body normally produces less urine at night due to circadian rhythms affecting antidiuretic hormone (ADH) release, but this mechanism can be disrupted with age or certain conditions, as noted in 1 and 1.
Management
Management of nocturia typically involves limiting fluids before bedtime, avoiding bladder irritants, elevating legs during the day to reduce fluid accumulation, treating underlying conditions, and sometimes medications like desmopressin to reduce nighttime urine production or anticholinergics for overactive bladder, as recommended in the most recent guidance 1.
Key Considerations
It is essential to evaluate and treat underlying medical conditions that may be contributing to nocturia, as highlighted in 1. The PLanning Appropriate Nocturia Evaluation and Treatment (PLANET) study provides practical guidance on evaluating and treating nocturia, including initial evaluation and supplementary evaluations.
Treatment Approach
The treatment approach should be individualized based on the underlying cause of nocturia and may involve lifestyle modifications, behavioral changes, and pharmacological interventions, as outlined in 1 and 1. Desmopressin may be considered to reduce nighttime urine production, especially in patients with nocturnal polyuria, as noted in 1.
From the Research
Nocturia Characteristics
- Nocturia is defined as the urge to urinate at night when the micturition was directly preceded and followed by sleep 2
- It is a condition characterized by the need to awaken ≥ 1 times per night to void 3
- Nocturia is a frequent condition among older adults and entails detrimental effects with regard to sleeping, sexual activity, comfort, depression, mental function and vitality 4
Causes of Nocturia
- The most common causal factor is nighttime overproduction of urine 3
- Nocturia can be caused by a combination of factors including decreased arousal in the brain, decreased urine production rate in the kidneys and increased functional bladder capacity 5
- Risk factors of nocturia such as hypertension, cardiovascular diseases, diabetes mellitus, cerebrovascular accidents and depression have also been associated with dysfunction of the circadian clock system 5
Nocturia at Night
- Nocturia is more common at night due to the body's natural circadian rhythm, which regulates the production of urine and the sensation of urgency 5
- The circadian clock system modulates the triad of micturition, including decreased arousal in the brain, decreased urine production rate in the kidneys and increased functional bladder capacity 5
- Nocturnal polyuria, which is an abnormally large volume of urine during sleep associated with a decreased daytime urine production, can also contribute to nocturia at night 4
Diagnosis and Treatment
- A Frequency Volume Chart (FVC), overnight water deprivation test with renal concentrating capacity test, and the nocturnal bladder capacity index are some of the methods that help establish the underlying pathology of this condition and hence define an adequate treatment plan 4
- Treatment strategies should always involve lifestyle changes and behavioral modifications, with the targeted treatment of underlying medical conditions that may cause nocturia 6
- Desmopressin remains the only drug approved specifically for the treatment of nocturia, and it can be used to reduce the number of nocturia episodes and improve the overall quality of life and sleep 2, 6