Pulmonary hypertension affects 8 percent of patients with systemic lupus erythematosus (SLE), a new meta-analysis shows.
But pulmonary hypertension (PH) does not affect all lupus patients equally. A subgroup analysis showed that men, adults, and non-Asian patients are the most affected by the disease.
The study, “Prevalence of pulmonary hypertension in systemic lupus erythematosus: a meta-analysis,” was published in the Irish Journal of Medical Science.
PH is a progressive disease characterized by an increased resistance to blood flow in the lung’s blood vessels, leading to a pressure overload in the heart’s right ventricle.
While several studies have linked this serious and potentially life-threatening condition with lupus, results concerning the link between both diseases remain variable.
To address that, researchers at Anhui Medical University reviewed observational studies assessing the prevalence of PH in lupus patients. Their analysis included 23 studies published before November 2017.
“The studies varied in size between 28 and 1,934 subjects, with an overall sample size across the studies of 7,121,” the researchers wrote.
The overall prevalence of PH was 8 percent, which was in agreement with prior analysis. However, the prevalence of PH depended on several factors, including gender, age, geographical location, the year of the study publication, and the methods used for PH diagnosis.
The disease was more common in men (12%), adult patients (9%), and in non-Asian locations (10%). And, while studies published before 2011 had a PH prevalence of 7 percent, those published in more recent years had a prevalence of 9 percent.
The standard method for diagnosing PH is right heart catheterization (RHC), a procedure that inserts a flexible tube (catheter) in the groin or neck to reach the pulmonary arteries and measure the pressure. Another method is the echocardiogram, where sound waves are used to generate a dynamic picture of the heart and measure pulmonary artery pressure.
Overall, “our study confirms that PH is prevalent in SLE patients, but it was significantly different between different gender, age, regions, year of publication, and diagnostic methods,” the research team wrote.
“In addition, our study also highlights the need for efficient identification of PH in SLE,” the study concluded.
While the study suggests that an association exists between lupus and PH, the type of studies included in the analysis prevented researchers from establishing a causal relationship. Longitudinal and intervention studies would be required to address if lupus may lead to the development of PH.