Endocrine Abstracts

Introduction: The clinical profile of patients with primary hyperparathyroidism has changed significantly in the last decades considering the fact that most cases are asymptomatic. This could be attributed to early diagnosis due to routinely serum calcium measurement. Only 5–27% of patients present with symptoms or signs related to osteoporosis, nephrolithiasis and hypercalcaemia. However, in patients with asymptomatic primary hyperparathyroidism (APHP) data concerning the incidence of these disorders are sparse.

The aim of our study was to record the incidence of nephrolithiasis and osteoporosis in patients with APHP.

Patients and Methods: 57 women, aged 62.8 ± 13.3 years, with APHP and normal renal function (GFR >60 ml/min/1.73 m²) were studied retrospectively. None of the patients was on treatment with bisphosphonates, denosumab, thiazide diuretics or calcium and vitamin D supplements. All were assessed with serum calcium (corrected for albumin), phosphorus, iPTH, 250HD3 and creatinine levels, twenty-four-hour urinary calcium and creatinine levels, while GFR was calculated. Kidney ultrasound and bone density measurement (BMD) with DEXA were performed. Osteoporosis was considered when T-score was less than −2.5 at any site (L2-L4, femur neck and distal radius).

Results: Twenty out of the 57 patients with APHP (35.0%) had nephrolithiasis and 25 (43.8%) had osteoporosis. Patients with nephrolithiasis vs those without, had higher 250HD3 (24.6 ± 8.0 vs 17.1 ± 7.7 ng/ml, P < 0.003), while there was no difference in age, BMI, serum calcium and PTH levels, and twenty-four-hour urinary calcium excretion (P >0.05). Patients with osteoporosis were older (69.3 ±10.0 vs 57.4 ± 13.1 years, P < 0.001) and had higher serum PTH levels (160.6 ± 93.9 vs 101.3 ± 21.5 pg/ml, P = 0.002), but did not differ in other parameters from women without osteoporosis.

Conclusions: Nephrolithiasis and osteoporosis are common in patients with asymptomatic primary hyperparathyroidism and therefore, bone mass density evaluation and kidney ultrasound should be included in the initial work up for early diagnosis and management.