Objective: To assess highly sensitive C-reactive protein (hs-CRP) and interleukin-6 (IL-6) as inflammatory biomarkers in patients with asymptomatic primary hyperparathyroidism (PHPT). Materials and Methods: A total of 26 patients with asymptomatic PHPT and 22 age- and sex-matched individuals as a control group were recruited for the study. Corrected serum calcium, phosphorus, alkaline phosphatase, serum 25-hydroxyvitamin D, intact parathyroid hormone (PTH), hs-CRP and IL-6 were measured for all subjects. Results: Serum hs-CRP and IL-6 were significantly higher in asymptomatic PHPT patients than in the control group (hs-CRP: 4.15 +/- 0.54 vs. 2.24 +/- 0.11 mg/l; IL-6: 4.50 +/- 0.80 vs. 2.56 +/- 0.29 pg/ml; p < 0.001). Moreover, in asymptomatic PHPT patients, serum PTH was significantly correlated with hs-CRP and IL-6 (r = 0.820, p < 0.001 and r = 0.787, p < 0.001, respectively). Conclusion: Inflammatory biomarkers were higher in patients with asymptomatic PHPT than in controls. Moreover, serum PTH was significantly correlated with inflammatory biomarkers which may suggest a subclinical inflammatory response in this group of patients. Copyright (C) 2011 S. Karger AG, Basel