8032 Clinical And Laboratory Characteristics Of Patients With Primary Hyperparathyroidism Followed At A Brazilian University Hospital

Abstract Disclosure: G. Koga: None. D. Amorim: None. L.M. dos Santos: None. D. Calixto: None. M. Ohe: None. J.G. Vieira: None. M. Lazaretti-Castro: None. Primary hyperparathyroidism (PHPT) is an endocrine disorder characterized by hypercalcemia due to hyperfunction of parathyroid glands. Its clinical presentation has been changing, becoming mostly asymptomatic. However, there are few data on developing countries.Objective: to describe clinical and biochemical features of primary hyperparathyroidism in a Brazilian population of a tertiary hospital. Methods: 259 individuals with PHPT are followed in a school-hospital in Sao Paulo in the last 2 years and this preliminary analysis included 161 of them. Clinical and laboratorial data were obtained by reviewing medical records. Data are presented as median [min-max] and statistical differences were considered if p<0.05. Results: 133 (82.6%) were women (3.7:1 female:male ratio) with a median age at diagnosis of 63 years [24-88]. There was higher prevalence of Caucasian (62.7%) then among Afro-descendants and Asians/indigenous: 35.4% and 1.9%, respectively. 99 (61.5%) patients were asymptomatic. Symptoms were observed in 38,5% (nephrolithiasis, fractures, bone pain, hypercalcemic crisis). Target organ involvement was evaluated: 48.4% had osteoporosis, and 47.2% kidney stones. At diagnosis, median total calcium (tCa) was 11.2 mg/dL [10.0-19.1], ionized calcium (iCa) 1.48 mmol/L [1.30-2.48], PTH 277.7 pg/mL [51.4-2374.0] and 25OHD 23.5 ng/mL [5.0-54.2]. Symptomatic patients were diagnosed younger (61 [24-83] vs 64 [31-88]; p=0.036), had higher tCa (11.4 [10.2-19.1] vs 11.2 [10-16]; p=0.049) and greater prevalence of 25OHD<20 ng/mL (50.0 vs 30.4%; p=0.03) than asymptomatic. Patients with severe hypercalcemia (>14 mg/dL) were diagnosed younger than those with non-severe hypercalcemia (52 [41-54] vs 63 [24-88] years; p=0.002). Patients with osteoporosis had older age at diagnosis compared to those without (64.0 [42-86] vs 61.5 [24-88]; p=0.018). Histological data were obtained from 94 individuals out of 104 submitted to surgery: 59.6% had single adenoma, 39.3% hyperplasia or multiple adenomas and 1.1% parathyroid carcinoma. Patients with single adenoma had higher levels of tCa and iCa than those with multiglandular disease (median of 11.4 [10.0-19.1] vs 10.9 [10.3-13.4]; p=0.042 and 1.52 [1.32-2.48] vs 1.43 [1.30-1.59]; p=0.02, respectively). Conclusion: Our preliminary data showed that most of the patients were Caucasian women presenting with asymptomatic disease. Compared with other countries, we still have a greater proportion of symptomatic presentations (38.5%) and multiglandular diseases (39.3%) than the reported in literature. Severe forms were diagnosed earlier, in younger patients and with a single adenoma, suggesting that they may have a different disease from the asymptomatic ones. These aspects demonstrate that there may be ethnic and environmental influences interfering with the presentation of this disease. Presentation: 6/2/2024