Heterogeneous Phenotypes of Primary Hyperparathyroidism in Romania: Characterization of a Large Cohort.

Background: Primary hyperparathyroidism (PHPT) has undergone notable clinical changes over recent decades, with asymptomatic cases now prevailing in Western countries. In contrast, a broad spectrum of clinical manifestations remains common in Romania, an Eastern European country. This study aims to provide a representative descriptive analysis of clinical presentations and related complications observed in this setting. Methods: We performed a cross-sectional, single-center study of 413 consecutive PHPT cases diagnosed between 2000 and 2020 at a tertiary endocrinology center in Romania. Data included demographics, clinical features, biochemistry, bone turnover markers, 25OHD, BMD by DXA, TBS, fractures, renal involvement, and etiology. Results: Patients were predominantly female (88.6%), with a mean age of 60 ± 11.7 years and a mean BMI of 27.3 ± 5.7 kg/m2. Familial forms were identified in 4.4%. Mean serum calcium was 11.28 ± 1.09 mg/dL, mean PTH 248.31 ± 361.94 pg/mL, and mean 25OHD 17.95 ± 9.6 ng/mL. Symptomatic hypercalcemia was present in 23.2% and severe vitamin D deficiency in 21%. Fractures were present in 25.2% and osteitis fibrosa cystica in 1.7%. Mean T-scores (SD): LS -2.23, FN -1.85, 1/3 distal radius -1.96. Osteoporosis prevalence: LS 47%, FN 24.1%, 1/3 distal radius 38%. Mean TBS was 1.258 ± 0.115. Renal involvement included calcifications (56.7%), nephrolithiasis (53%), nephrocalcinosis (3.6%), hypercalciuria (31.7%), and reduced renal function (9.93%). Non-classical manifestations were mainly cardiovascular (58%) and osteoarticular (24.5%). Parathyroidectomy was performed in 217 patients (53%); histopathology showed adenoma (88.8%), carcinoma (5.2%), and hyperplasia (6%), with a mean adenoma weight of 2.86 ± 5.92 g. Conclusions: PHPT in Romania shows a heterogeneous phenotypic spectrum, reflecting variability in clinical presentation and suggesting an evolving epidemiological profile.