Assessment of the Relationship Between the Six-Minute Walk Test (6MWT) With Serum Chloride Level and Mean Pulmonary Arterial Pressure in Patients With Pulmonary Arterial Hypertension.

Pulmonary artery hypertension (PAH) is a fatal disease associated with high mortality, especially in countries with limited health resources in terms of lack of access to diagnostic and therapeutic evaluations. Therefore, it is necessary to discover inexpensive and available serum biomarkers for examining patients. This study investigates the relationship between PAH patients' six-minute walk (6MWT) distance, serum chloride levels, and mean pulmonary arterial pressure (mPAP). In this cross-sectional study, patients with PAH referring to the pulmonary hypertension clinic of our tertiary hospital were included. Then, the patient's demographic information and clinical findings were recorded, and the serum level of chloride and the 6MWT were examined in the patients. In the present study, 70 PAH patients were evaluated. All patients were female, and the mean age of the patients was 39.44 ± 8.33 years old. Hypochloremia was considered as serum chloride < 97 mmol/L in our study. The mPAP of patients with hypochloremia was significantly higher than non-hypochloremia patients (p < 0.001). The serum chloride levels had a significant positive correlation with the 6MWT distance (r = 0.634, p < 0.001). According to the linear regression analysis results, serum chloride level was a significant predictor of 6MWT distance even after adjustment for age and creatinine (β = 0.48; p = 0.002). Serum chloride level can be used as an inexpensive method for the evaluation of disease severity in PAH patients, especially in patients with higher time since the diagnosis of PAH.