Chronic anemic hypoxia is associated with increased pulmonary artery pressure (PAP) in patients with systemic lupus erythematosus (SLE), according to Dr. Ki-Jo Kim and associates.

In this study of 132 SLE patients, those with increased PAP had significantly lower oxygen delivery levels than those with normal PAP. Oxygen delivery also was directly correlated with hemoglobin levels. Increased PAP was more likely when patients had a longer duration of anemia during the preceding 6-24 months, and patients who had anemia for more than half of the preceding 6 months also had increased risk.

Higher levels of interleukin-6 likely plays a role in raising PAP levels, as IL-6 levels increased with higher PAP but decreased across tertiles of hemoglobin, the investigators noted. Pulmonary arterial hypertension is a rare but serious complication of SLE.

Find the full study in Arthritis Care & Research (doi:10.1002/acr.22630).