B-mode ultrasound assessment of carotid artery structural features in patients with normocalcaemic hyperparathyroidism

Introduction: Normocalcaemic hyperparathyroidism is a condition first defined in 2008, characterized by normal se- rum calcium and high parathormone levels. Although normocalcaemic hyperparathyroidism is considered to have a milder clinical picture compared to asymptomatic primary hyperparathyroidism, recent studies have shown that it may be associated with osteoporosis, insulin resistance, metabolic syndrome, and cardiovascular risk factors. Considering that normo- calcaemic hyperparathyroidism may pose a cardiovascular risk in the setting of carotid atherosclerosis, we sought to examine the structural features of the carotid artery in patients with normocalcaemic hyperparathyroidism compared to a control group. Material and Methods: After excluding patients with hypertension, diabetes, and dyslipidaemia (other factors contributing to atheroscle- rosis), 37 (32 females, 5 males) patients with normocalcaemic hyperparathyroidism with a mean age of 51.2 +/- 8 (min: 32, max: 66) years and 40 controls (31 females, 9 males) with a mean age of 49.3 +/- 7.5 (min: 34, max: 64) years with normal serum albumin-corrected calcium and parathyroid hormone levels were included in the study. Structural features of the carotid artery including intima-media thickness (mean and maximum), lumen diameter, and the presence of plaque were assessed using B-mode ultrasound. Results: On ANCOVA analysis corrected for atherosclerotic factors (body mass index, waist circumference, fasting plasma glucose, serum cholesterol, lipid, and blood pressure), greater mean intima-media thickness was found in patients with normocalcaemic hyperparathyroidism than in controls (0.65 mm vs. 0.59 mm, respectively) (p = 0.023). Maximum ca- rotid intima-media thickness was also greater in patients with normocalcaemic hyperparathyroidism compared to controls (0.80 mm vs. 0.75 mm, respectively) (p = 0.044). The study groups did not show a significant difference in lumen diameter and the presence of carotid plaque. In addition, a negative correlation was found between parathormone (PTH) level and lumen diameter. Conclusion: The findings of this study show that as with asymptomatic primary hyperparathyroidism, normocalcaemic hyperparathy- roidism may be associated with increased cardiovascular risk by predisposing to atherosclerosis. (Endokrynol Pol 2023; 74 (1): 67-73)