Association between neutrophil-to-lymphocyte ratio and parathyroid hormone in patients with primary hyperparathyroidism

Introduction: Primary hyperparathyroidism (PHPT) is associated with adverse cardiovascular outcomes which may result from an increase in systemic inflammation. Previously we have shown that serum parathyroid hormone (PTH) levels are independently associated with inflammatory indicators. The neutrophil-to-lymphocyte ratio (NLR) is an inexpensive, widely available marker of inflammation. In the present study, we aimed to assess the longitudinal changes in NLR before and after parathyroidectomy. Material and methods: This retrospective study included 95 patients diagnosed with PHPT who underwent parathyroidectomy between 2006 and 2016. Follow-up complete blood counts were available in 31 patients. Results: At diagnosis, 43 (45%) patients presented with overt clinical symptoms and had higher serum calcium and PTH levels. Preoperative NLR was positively correlated with total white blood cell count (p = 0.001), serum calcium (p = 0.001), and PTH level (p = 0.013). The NLR was not associated with sex, age, comorbidities, or parathyroid weight. Among patients who were cured of PHPT, the median NLR decreased from 2.26 to 1.77 after parathyroidectomy (p = 0.037). There was no difference in hemoglobin, total white blood cells, or platelet count before and after surgery. Conclusions: We found a positive correlation of preoperative NLR with calcium and PTH levels in PHPT patients. After curative parathyroidectomy, NLR modestly decreased without changes in other hematological parameters.