Urinary symptoms are frequent in patients with systemic sclerosis (SSc), especially in patients with limited cutaneous SSc, which have a 2.2 times higher risk of developing urinary symptoms than other SSc patients, and in patients who are positive for anti-centromere antibodies, who have a 2.8 times increased risk.
Findings from the European multicenter study, “The limited cutaneous form of systemic sclerosis is associated with urinary incontinence: an international multicentre study,” appeared in a recent issue of the journal Rheumatology.
The study (NCT01971294) enrolled a total of 334 patients diagnosed with systemic sclerosis from five centers in France, Italy, and Switzerland. All patients responded to questionnaires to assess urinary incontinence and its impact on their quality of life.
About 63 percent of the participants reported having urinary incontinence. The majority of the patients were older and females, with diagnosed limited cutaneous systemic sclerosis (lcSSc) or who tested positive for anti-centromere antibodies (ACAs). This finding contrasted with previous beliefs that urinary tract involvement in systemic sclerosis was a rare event.
More recent studies have showed that patients with SSc present bladder volume and function changes more frequently compared to healthy individuals. Changes in the bladder tissue and blood vessel network have also been reported in SSc patients, which can help explain the incidence of urinary symptoms in this population.
In addition to lcSSc and ACAs’ association to urinary incontinence, the team also found that female patients had a 10.8-fold increased risk of having urinary symptoms. Also, breathing difficulties, higher body mass index (BMI), and disability were found to be risk factors for urinary incontinence.
But the higher incidence of urinary incontinence in limited cutaneous systemic sclerosis and positive ACAs patients could not only be explained by the presence of comorbidities such as diabetes, difficulty breathing, or pulmonary hypertension.
When the analysis was adjusted to all possible cumulative risk factors, patients with lcSSc and positive ACAs still had a 3.4-fold higher risk for urinary incontinence than patients with only lcSSc or ACAs.
“Autonomic nervous system dysfunction, which has been shown to be frequent in SSc patients, is a promising candidate to fill the gap and explain the association,” the researchers wrote. “Indeed, antibodies inhibiting parasympathetic neurotransmission have been shown to be directly responsible of urinary symptoms in another autoimmune disease [Sjögren’s syndrome],” they added.
Still, additional studies addressing this hypothesis of association of nervous system dysfunction and urinary symptoms in systemic sclerosis are warranted.
Lower urinary tract symptoms can have great impact on many aspects of daily life, but only a minority of the study participants that had urinary incontinence sought medical attention. For many of the patients, urological symptoms may not be seen as a priority, taking into account all other concerns they have to deal with due to SSc. However, such symptoms may lead to urinary tract infection, which has been associated with mortality.
This study highlights the incidence of urinary tract symptoms among SSc population. It also identified risk factors that may contribute the detection of patients at risk and improve patient care.