Early disease onset and long disease duration may increase the risk of additional diseases in patients with ankylosing spondylitis, according to the results of a Swedish study.
The study, “Patterns of comorbidity and disease characteristics among patients with ankylosing spondylitis—a cross-sectional study,” was published in the journal Clinical Rheumatology.
Researchers evaluated patterns of comorbidity – the presence of one or more additional diseases – in a population of Swedish patients with ankylosing spondylitis. They focused on four categories of comorbidity: Category A included arrhythmias, conduction disorders, and valvular heart disease; category B included atherosclerosis and atherosclerotic cardiovascular disease; category C included spinal and non-spinal fractures; and category D included obstructive sleep apnea syndrome.
In total, the team analyzed 346 patients with ankylosing spondylitis, with a mean age of 56.
On average, disease onset occurred when patients were 25, and the mean disease duration at the end of the evaluation period was 31.
The analysis revealed that the presence of comorbidity varied according to age, disease duration, and disease onset. Specifically, age was associated with all four categories of comorbidity, although it affected more patients with atherosclerotic cardiovascular disease (category B). Men were more often linked with arrhythmias, conduction disorders, valvular heart disease (category A), and obstructive sleep apnea syndrome (category D).
Long disease duration and early onset were also associated with comorbidities from category A, including arrhythmias, conduction disorders, and valvular heart disease.
Patients with atherosclerotic cardiovascular disease were linked to numerous other comorbidities.
Therapeutics for ankylosing spondylitis, including disease-modifying ; drugs, inhibitors of tumor necrosis factor, and glucocorticoid treatments, showed no association with the comorbidities evaluated. Researchers also did not find a link between comorbidities and levels of the inflammation marker C-reactive protein or spinal mobility.
Overall, “multiple coexisting comorbidities were frequent in AS, especially among patients with CVD [cardiovascular disease]. High age was associated with comorbidity, but among disease characteristics only long disease duration and early disease onset seem to contribute to the risk of comorbidity,” the researchers noted.
The team acknowledged that further studies are needed “to identify predictors and measures to prevent comorbidity in the AS population.”