Introduction:
Nocturia is a lower urinary tract symptom and is one of the common causes of disturbed sleep in the elderly. It causes fragmentation of the sleep cycle and negatively impacts the quality of the sleep cycle, resulting in daytime tiredness.
Nocturia is associated with falls and fall-related morbidity. Nocturia is caused due to lower urinary tract dysfunctions such as overactive bladder syndrome or benign prostatic hyperplasia due to bladder outlet obstruction. Sleep quality usually deteriorates, and nocturia worsens the problem by fragmenting the sleep cycle.
What Are the Normal Voiding Patterns?
The micturition cycle has two phases:
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Storage.
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Voiding.
This is controlled through somatic and autonomic pathways. During storage, the bladder is filled with urine and receptive relaxation. A closed bladder maintains continence. It is a subconscious process, and the individual will have no sensation of bladder filling until the bladder is half full. Bladder sensation is brought by sensory nerves that sense the stretch of the detrusor. An urge to void is felt when the bladder is full.
The rate of urine production is also an important factor in how often individuals void and is assessed by complex neurohumoral homeostatic mechanisms. For example, arginine vasopressin is an antidiuretic hormone and a potent pressor agent which increases blood pressure.
There are two types of vasopressin receptors:
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Type 1 (V1).
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Type 2 (V2).
The antidiuretic effect is seen through V2 receptors in the nephrons.
What Is Nocturia?
In 2002 the ICS (International continence society) stated that nocturia is waking once or more to void during nighttime. Each void is followed by sleep, in contrast to nocturnal enuresis, where voiding occurs in sleep. When an individual leaks due to failure to reach the toilet in time during the night, it is called incontinence.
Night time is the period between going to sleep with the intention of sleeping and rising. Waking once at night to urinate is normal and not bothersome. Hence the clinically important level of nocturia appears to be greater than or equal to two voids.
Is Nocturia Common?
The data collected from several studies concluded that nocturia is highly prevalent in the general population but is common in the elderly. The definition states that nocturia as greater than or equal to two voids is less prevalent than nocturia greater than or equal to one void. The former is more likely to be irrelevant.
In the younger population, nocturia greater than or equal to one is more prevalent in women than in men, whereas in older age groups, the former reverse is true. This may be due to the increase in benign prostatic hyperplasia in men, and older women may accept the signs as a normal part of aging and are less likely to report them.
What Are the Etiological Factors?
Aging is considered one of the major risk factors for nocturia. Other factors include:
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Urine Storage: When there is a reduction in the capacity of the bladder to store urine, leading to increased frequency of micturition, is the reason why lower urinary tract dysfunction leads to nocturia. This reduction can be consequent and functional upon common conditions such as detrusor overactivity, linked to prostate bladder hyperplasia and overactive bladder syndrome, or due to reduced bladder capacity consequent upon bladder fibrosis. Overactive bladder syndrome is a common chronic symptom of urinary urgency with or without urgency incontinence, with nocturia and frequency in the absence of metabolic conditions. Overactive bladder syndrome is a clinical presentation in approximately one-third of individuals reporting nocturia.
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Urine Production: There is an increased need to empty the bladder due to the overproduction of urine during sleep. This is known as polyuria, an increase in urine production occurring throughout the day or nocturnal. In these cases, the bladder fills more quickly, and the individual is prone to frequent visits to pass urine. Nocturnal polyuria increases with age and is implicated in etiology. The pathology of nocturnal polyuria is related to age-defined changes in the renal function that consist of water and sodium-conserving mechanisms.
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Sleep Disturbance: Nocturia is directly related to the quality of sleep. The conditions that lead to sleep disturbances are commonly associated with an incidence of nocturia, especially insomnia, anxiety, depression, snoring, pruritus, burning mouth syndrome, and chronic pain. The nocturia may be due to convenience voids taken after waking due to primary sleep problems, or nocturia itself is the cause of sleep disturbance.
How Is Nocturia Assessed?
The main goal of clinical assessment of the individual with nocturia is to establish the nature and severity of symptoms, the impact on quality of sleep, and the causative and contributing factors. The assessment involves history taking, examination, and documents of the timing and volume after every void.
In addition, the type and volume of the drink are noted and documented for urgency and incontinence episodes. The advantage of this is that it provides objective corroboration of the patient's symptoms, establishes whether the individual is polyuric which allows an estimation of the functional bladder capacity, and provides information about contributory lifestyle habits.
What Is the Management of Nocturia?
The management includes the following:
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Lifestyle Modification: Lifestyle factors such as caffeine and fluid intake have been considered to be associated. Healthcare providers usually advise lifestyle modification to limit the nocturia episodes, which is based on logic and anecdotal evidence. For example, individuals have been advised fluid restriction, limiting time in bed, moderate exercise, and keeping warm in bed.
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Overactive Bladder: Antimuscarinic agents are used for the treatment of overactive bladder. These agents bind to the muscarinic receptors of the detrusor muscle by inhibiting the severity and frequency of non-voiding contractions. As a result, they lessen the sensations of urgency and reduce urinary frequency and urgency incontinence episodes.
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Management of Nocturnal Polyuria: Decompression acetate is a synthetic analog used in nocturia.
Conclusion:
Nocturia and nocturnal polyuria is common among the elderly population and leads to impaired quality of sleep which is associated with morbidity and mortality. Therefore, it is a major public health concern. Treatment helps in improving the number of nighttime voids.
