Endocrine Abstracts

Introduction

Primary hyperparathyroidism (PHPT) is characterized by excessive secretion of parathyroid hormone (PTH) from one or more parathyroid glands. PTH has a central role in the regulation of calcium and phosphate and the classic disorder causes primarily hypercalcemia associated with renal and bone manifestations. Non-classical symptoms are also present including cardiovascular, gastrointestinal, psychiatric, neuro-cognitive disorders. Regarding cardiovascular manifestations it is well established that patients with PHPT experience higher cardiovascular morbidity and mortality. Left ventricular structure has been shown to be affected in PHPT and patients present with increased left ventricular mass, which is regarded as a strong, independent factor of cardiovascular mortality. Both serum calcium levels and parathyroid hormone (PTH) have been reported to be associated with left ventricular hypertrophy.

Aim of the study

The aim of the study was to test whether curative parathyroidectomy (PTX) could contribute in decrease of left ventricular mass, leading to reverse of harmful effects of PHPT on cardiovascular system, in patients suffering from primary hyperparathyroidism.

Methods

We prospectively evaluated 10 patients scheduled to undergo parathyroidectomy for primary hyperparathyroidism (9 women and 1 man, with mean age 59.1 [± 10.5] years, mean BMI 26.4 [± 5.0], PTH at diagnosis 11.93 [± 3.14] pg/ml, and serum calcium 11.13 [± 0.47] mg/dl. Patients had no history of heart disease (including hypertension, atrial fibrillation, valve disease and diabetes).

Echocardiographic evaluation was conducted by a single investigator with GE Vivid S5 ultrasound instrument and left ventricular end-diastolic dimension (LVEDD), interventricular septal thickness at end-diastole (IVSd) and posterior wall thickness at end-diastole (PWd) were measured. Left ventricular mass (LVM) was calculated as follows: LVM (g) = 0.8 × 1.04 [(LVEDD + IVSd + PWd)3 - (LVEDD)3] + 0.6. Left ventricular mass index (LVMI) was calculated as LVM divided by body surface area. Normal ranges were assumed as 43–95 g/m² for women and 49–115 g/m² for men.

Results

All patients had a normal LVMI before parathyroidectomy (mean LVMI 67.30 [± 17.04], and they were assessed 2 days before and 3 months after curative surgery. 3 months after PTX mean LVMI was reduced in all patients with mean values of 63.10 [14.16] g/m².

Conclusion

LVMI was reduced in all patients 3 months after parathyroidectomy. Despite the fact that LVM was within normal range before surgery the study showed a decrease in the mean LVMI for all patients. This is indicative that an early diastolic dysfunction exists in PHPT patients independent of other risk factors and it is normalized after surgery.