Background: Previous studies have found that nonsteroidal anti-inflammatory drugs (NSAIDs) and statins may impact erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) levels in patients. The current study was performed to determine if NSAID or statin use is associated with lower ESR and CRP in patients with biopsy-proven giant cell arteritis (GCA).
Methods: A retrospective cross-sectional study was conducted that included 161 patients via chart review. Charts of patients with GCA seen at the University of Iowa Hospitals and Clinics from 1960 to 2008 were reviewed. Inclusion criteria were adequate medication records, serum ESR and/or CRP on record, no prior corticosteroid use, and biopsy-positive GCA. Exclusion criteria were the presence of diseases known to elevate ESR or CRP. Main outcome measures included ESR and CRP values measured while evaluating patients for GCA but prior to receiving treatment.
Results: Statin nonusers had an ESR of 85.0 mm per hour (interquartile range [IQR] = 60-110 mm per hour) and a CRP of 8.7 mg/dL (IQR = 2.7-16.2 mg/dL). Statin users had an ESR of 57.5 mm per hour (IQR = 35-85) and a CRP of 2.4 mg/dL (IQR = 0.8-15.9 mg/dL). Statin use was associated with a lower ESR (P = 0.005), while there was no significant association with a lower CRP (P = 0.127). NSAID nonusers had an ESR of 98.0 mm per hour (IQR = 64-116) and a CRP of 8.7 mg/dL (IQR = 2.1-16.2 mg/dL). NSAID users had an ESR of 75.0 mm per hour (IQR = 46-98.5 mm per hour) and CRP of 8.0 mg/dL (IQR. = 1.5-16.2 mg/dL). NSAID use was associated with a lower ESR (P = 0.004), but there was no significant association with a lower CRP (P = 0.522).
Conclusion: Statin use and NSAID use were associated with a lower ESR; however, they were not associated with lower CRP values. Clinicians should be aware that statin or NSAID use is associated with lower ESR in patients with GCA, and this test may therefore have lower sensitivity and specificity for recognizing patients with GCA, and CRP may be a superior test to evaluate patients for GCA.