ALDH7A1 and chronic obstructive pulmonary disease: BMI = body mass index; COPD = chronic obstructive pulmonary disease; ED = emergency department; ERA = endothelin receptor antagonists; FVC = forced vital capacity; ILD = interstitial lung disease; IP = inpatient; PDE = phosphodiesterase; PH = pulmonary hypertension; PPI = proton pump inhibitors; SD = standard deviation; sGC = guanylate cyclase stimulators.