Nailfold Capillary Changes in Primary Hyperparathyroidism

OBJECTIVE: This study aimed to evaluate morphological changes in nailfold capillaries in patients with primary hyperparathyroidism (PHPT) and to investigate their association with serum parathormone (PTH) and calcium levels. DESIGN: Cross-sectional study. PATIENTS: The study included 62 patients with PHPT and 34 matched healthy controls. MEASUREMENTS: Serum levels of creatinine, calcium, phosphorus, magnesium, albumin, PTH, and 25-hydroxy vitamin D were measured in both PHPT patients and healthy controls. Nail fold capillary morphology was assessed using digital dermatoscopy. RESULTS: Minor morphological changes (MiMC) in nailfold capillaries were significantly more prevalent in the PHPT group compared with healthy controls (p = 0.001). The semiquantitative MiMC score was also significantly higher in the PHPT group (p < 0.001). Avascular area scores (AAS) showed positive correlations with plasma PTH, serum calcium levels, and age (r = 0.498, p < 0.001; r = 0.552, p < 0.001; and r = 0.346, p = 0.001, respectively). Serum calcium levels were independently associated with MiMC scores (p = 0.036), whereas both plasma PTH levels and age independently influenced AAS (p = 0.032 and p = 0.002, respectively). CONCLUSION: Microvascular alterations in nailfold capillaries were observed in patients with PHPT. These findings suggest that, in addition to the previously reported cardiovascular involvement, PHPT may also affect peripheral microcirculation at the capillary level.