PTGS2 and chronic obstructive pulmonary disease: The SSc group had a higher proportion of comorbidities such as diabetes mellitus, hypertension, dyslipidemia, CKD, COPD, CAD; a history of uncomplicated peptic ulcer disease; and concurrent use of antiplatelets, warfarin, traditional NSAIDs, COX-2 inhibitors, PPIs, H2RAs, and steroids (p < 0.001).