Biomarkers of hypercoagulability and inflammation in primary hyperparathyroidism

Severe primary hyperparathyroidism (PHP) has been associated with increased cardiovascular morbidity. Hypertension, dyslipidemia and impaired glucose metabolism were demonstrated in severe PHP, with improvement after surgery in these variables. Such an association in mild PHP is not known. The study was conducted to determine biomarkers of hypercoagulability and inflammation for cardiovascular disease in patients with primary hyperparathyroidism.

Patients (n=35) without CVD were evaluated. Patients were subdivided into two groups, severe (n=15) and mild (n=20) hyperparathyroidism, based on disease severity and whether they had indications for surgery. Results were compared with those obtained in 25, age and weight matched controls. Participants were examined in the hospital endocrine clinic and had measurement of fasting blood levels of calcium, phosphate, alkaline phosphatase, PTH, C-reactive protein, Serum IL-6, D-dimers, Fibrinogen, plasminogen activator inhibitor 1 [PAI-1], and white blood cells (WBC) count.

PAI-1 was significantly higher in symptomatic patients (41.4 g/L +/-20) vs. controls (32.5 g/L +/-13.0); (p=0.009). Levels of fibrinogen, d-dimers, IL-6, CRP and leukocytes were similar in patients and controls. Across all subjects PAI-1 was significantly correlated with PTH levels (f=8.44;p=0.005).

Patients with severe primary hyperparathyroidism have increased risk for cardiovascular disease, mainly due to the effect of PTH and also the duration and severity of disease. Elevated PAI-1 levels may imply that hypercoagulability may be involved in the pathogenesis of CVD in these patients.