Frequent urination at night has been identified as a potential side effect of drugs to treat hypertension. In this report by SADE OGUNTOLA, experts warn that in some instances, it may also signal undiagnosed diabetes or even uncontrolled hypertension.
It is not uncommon to wake up at night to urinate. However, when the urge to use the restroom at night is frequent, a good night’s sleep can be hard to achieve.
Certainly, frequent urge to use the restroom at night, a condition called nocturia, may be more common in people over the age of 60. But experts say experiencing this frequently at night could be a warning sign of hypertension in some individuals.
Hypertension, also known as high or raised blood pressure, affects millions of Nigerians. Blood pressure is created by the force of blood pushing against the walls of blood vessels (arteries) as it is pumped by the heart.
The higher the pressure, the harder the heart has to pump. Blood pressure reading comprises of two values: systolic and diastolic pressure. Any number above 140 over 90 is considered high.
According to a World Health Organisation (WHO) statistics, Africa has the highest percentage of cases of hypertension and about 23.9 per cent of Nigeria’s population aged 18 years and above is hypertensive, a ratio of almost one in every four Nigerian.
Risk factors leading to hypertension include high salt consumption, obesity, excessive alcohol consumption, tobacco consumption, sedentary lifestyle with lack of exercise and a family history of hypertension.
A study conducted in Japan found that the need to urinate in the night, called nocturia, may be linked to hypertension and high salt intake.
The researchers had presented the results of the study at the 83rd Annual Scientific Meeting of the Japanese Circulation Society. They suggested that urinating more than two times at night could in fact constitute a putative symptom of uncontrolled hypertension.
They had enrolled 3,749 residents of the town of Watari who had undergone an annual health check in 2017 and gathered information about their blood pressure levels and nocturia using questionnaires.
From the study, people who woke up at least once in the night to use the restroom were 40 per cent more likely to have high blood pressure, and those who woke up multiple times each night were at an even greater risk.
Researchers believe the connection between getting up to urinate at night and high blood pressure probably has to do with various factors including lifestyle, salt intake, ethnicity and genetic background.
Nonetheless, Dr Yemi Raji, a consultant nephrologist, University College Hospital (UCH), Ibadan, said frequent urination not typically a sign of hypertension.
Dr Raji stated that there is no specific symptom for hypertension, adding “that is why it is a silent killer”.
Nonetheless, he declared that in the early stages of chronic kidney disease, people who developed hypertension might frequent urinate at night.
“But hypertension on its own alone cannot cause frequent urination at night,” he added.
Professor Babatunde Salako, director-general of Nigerian Institute of Medical Research (NIMR), Lagos said such a habit could also be a sign of kidney or ureter (tubes connecting the kidneys to the bladder) problems, urinary bladder problems, or another medical condition, such as diabetes mellitus and urinary tract infection or bladder infection.
These infections cause frequent burning sensations and urgent urination throughout the day and night.
Professor Salako declared that frequent urination could also be a side effect of diuretics, what is called water pills, in persons who take it to control their raised blood pressure.
“The individual is likely to pass urine from time to time because what the drug does is to make the individual excrete water and salt to lower blood pressure,” he added.
According to Salako, a consultant nephrologist, individuals with urinary tract infection might end up urinating frequently; same as someone that takes plenty of fluids from time to time or that had experienced a stroke which had damaged the nerves in the bladder.
“The fact is if you take plenty of fluids from time to time, it may make you urinate more frequently. That is not abnormal. Generally when you notice an increase in your frequency of urination but you are drinking normally, it is a sign that you should go to the hospital to get yourself assessed properly,” he said.
Testing that may be required to know the cause of frequent urination includes blood sugar test to check for diabetes, urine culture; fluid deprivation test and imaging tests, such as ultrasounds or CT scans.
Professor Salako warned that early detection and management of hypertension are crucial to preventing heart disease, stroke and kidney failure.
Moreover, experts in another study in the Journal of the American Heart Association described frequent urination at night as an unrecognized symptom of uncontrolled hypertension in black men aged 35 to 49 years.
The 2019 study said although hypertension is assumed to have no symptoms, urinating more than twice at night could constitute a supposed symptom of uncontrolled hypertension that is potentially reversible. It was in the Journal of the American Heart Association.
This large community-based study in California had looked at 1673 black men and found that those with hypertension were 56 per cent more likely than men with normal blood pressures to have nocturia after adjustment for diabetes mellitus and sleep apnea.
Also, the prevalence of men that frequently wake up at night to urinate varied with their hypertension status, ranging from 24 per cent in men with normal blood pressure to 49 per cent in men whose hypertension was medically treated but uncontrolled.
Men with untreated hypertension was 39 per cent more likely than men with normal blood pressure to report nocturia, whereas men whose hypertension was treated and controlled were no more likely than men with normal blood pressure to report nocturia.
Among patients with treated and controlled hypertension, diuretic use increased the odds of nocturia after adjustment for both diabetes mellitus and sleep apnea.
Among patients with treated hypertension, men with nocturia were 2.47 times more likely to have elevated blood pressure after taken into consideration factors such as age, diabetes mellitus and sleep apnea.
According to them, “these data implicate nocturia (awakening at night to void) as a common symptom of uncontrolled hypertension—especially unsuccessfully treated hypertension—among relatively young middle aged black men that merits further medical attention.
“If tight control of blood pressure could alleviate a bothersome symptom such as nocturia, it would prove a powerful public health message to increase medication adherence.”
Also of importance is a healthy lifestyle that includes salt restriction, alcohol moderation, healthy eating, regular exercise, weight control, and smoking cessation.
Basically, frequent urination can result from one of three possible reasons: the bladder is having a hard time holding urine, producing more urine than usual during the day, or producing more urine during the night.
These may also be a sign of other health conditions, including bladder prolapse, a tumour of the bladder or prostate, and other disorders affecting sphincter control. Pregnant women and people with heart or liver failure and diabetes may also experience nocturia.
Moreover, with ageing, the body produces less of an antidiuretic hormone that enables it to retain fluid — this leads to more urine production during the night.