Abstract：
BACKGROUND: Normocalcemic primary hyperparathyroidism (nPHPT) is a condition characterized by persistently high levels of parathyroid hormone (PTH) and normal serum calcium levels in the absence of other causes for secondary hyperparathyroidism. The aim of the present study was to assess the clinical presentation and the biochemical characteristics in patients with nPHPT and to compare them with those in patients with hypercalcemic PHPT (hPHPT).
METHODS: The study included 316 patients (277 women and 39 men, average age 58.7 ± 12.1) diagnosed with PHPT. Total serum calcium, inorganic phosphates (PO4), PTH, urinary Ca (uCa), albumin, creatinine, 25(OH)D and bone markers (b-CTX and ALP) were examined in all of them. BMD of the lumbar spine (LS), distal third of the radius (DR), femoral neck (FN) and total proximal femur (TF) were measured by a dual-energy X-ray absorptiometry (DXA). The patients were divided into two groups according to albumin-corrected calcium (Ca) level - with hPHPT (Ca>2.62 mmol/L) and with nPHPT (Ca 2.12-2.62 mmol/l), without other causes for secondary hyperparathyroidism.
RESULTS: The frequency of nPHPT was 15.2%. Normocalcemic patients had lower levels of PTH, higher PO4 and 25(OH)D, and smaller parathyroid adenomas. No significant difference in the frequency of osteoporosis, low-energy fractures, nephrolithiasis and gastrointestinal disorders was found between nPHPT and hPHPT. There was no difference in BMD between the two groups.
CONCLUSIONS: The patients with nPHPT show a more favorable biochemical profile compared to those with hPHPT. Nevertheless, clinical manifestations and complications are similar, without a significant difference in the frequency of osteoporosis, nephrolithiasis, gastrointestinal disorders and low-energy fractures.
METHODS: The study included 316 patients (277 women and 39 men, average age 58.7 ± 12.1) diagnosed with PHPT. Total serum calcium, inorganic phosphates (PO4), PTH, urinary Ca (uCa), albumin, creatinine, 25(OH)D and bone markers (b-CTX and ALP) were examined in all of them. BMD of the lumbar spine (LS), distal third of the radius (DR), femoral neck (FN) and total proximal femur (TF) were measured by a dual-energy X-ray absorptiometry (DXA). The patients were divided into two groups according to albumin-corrected calcium (Ca) level - with hPHPT (Ca>2.62 mmol/L) and with nPHPT (Ca 2.12-2.62 mmol/l), without other causes for secondary hyperparathyroidism.
RESULTS: The frequency of nPHPT was 15.2%. Normocalcemic patients had lower levels of PTH, higher PO4 and 25(OH)D, and smaller parathyroid adenomas. No significant difference in the frequency of osteoporosis, low-energy fractures, nephrolithiasis and gastrointestinal disorders was found between nPHPT and hPHPT. There was no difference in BMD between the two groups.
CONCLUSIONS: The patients with nPHPT show a more favorable biochemical profile compared to those with hPHPT. Nevertheless, clinical manifestations and complications are similar, without a significant difference in the frequency of osteoporosis, nephrolithiasis, gastrointestinal disorders and low-energy fractures.
摘要：
背景：正常血钙原发性甲状旁腺功能亢进症（nPHPT）是一种以持续高水平的甲状旁腺激素（PTH）和正常的血清钙水平为特征的疾病，而没有其他原因导致继发性甲状旁腺功能亢进症。本研究的目的是评估nPHPT患者的临床表现和生化特征，并将其与高血钙PHPT（hPHPT）患者进行比较。
方法：该研究包括316名患者（277名女性和39名男性，平均年龄58.7±12.1）诊断为PHPT。血清总钙,无机磷酸盐（PO4），PTH,尿Ca(uCa),白蛋白,肌酐,在所有这些中检查25(OH)D和骨标志物(b-CTX和ALP)。腰椎BMD（LS），桡骨远端三分之一(DR),股骨颈（FN）和股骨近端（TF）通过双能X线吸收法（DXA）测量。根据白蛋白校正的钙（Ca）水平将患者分为两组-hPHPT（Ca>2.62mmol/L）和nPHPT（Ca2.12-2.62mmol/l），没有其他原因导致继发性甲状旁腺功能亢进。
结果：nPHPT的频率为15.2%。正常血钙患者的PTH水平较低，较高的PO4和25(OH)D，和较小的甲状旁腺腺瘤。骨质疏松症的发生频率没有显著差异，低能量断裂,在nPHPT和hPHPT之间发现肾结石和胃肠道疾病。两组之间的BMD没有差异。
结论：与hPHPT患者相比，nPHPT患者表现出更有利的生化特征。然而，临床表现和并发症相似，骨质疏松症的发生频率没有显着差异，肾结石,胃肠道疾病和低能量骨折。
方法：该研究包括316名患者（277名女性和39名男性，平均年龄58.7±12.1）诊断为PHPT。血清总钙,无机磷酸盐（PO4），PTH,尿Ca(uCa),白蛋白,肌酐,在所有这些中检查25(OH)D和骨标志物(b-CTX和ALP)。腰椎BMD（LS），桡骨远端三分之一(DR),股骨颈（FN）和股骨近端（TF）通过双能X线吸收法（DXA）测量。根据白蛋白校正的钙（Ca）水平将患者分为两组-hPHPT（Ca>2.62mmol/L）和nPHPT（Ca2.12-2.62mmol/l），没有其他原因导致继发性甲状旁腺功能亢进。
结果：nPHPT的频率为15.2%。正常血钙患者的PTH水平较低，较高的PO4和25(OH)D，和较小的甲状旁腺腺瘤。骨质疏松症的发生频率没有显著差异，低能量断裂,在nPHPT和hPHPT之间发现肾结石和胃肠道疾病。两组之间的BMD没有差异。
结论：与hPHPT患者相比，nPHPT患者表现出更有利的生化特征。然而，临床表现和并发症相似，骨质疏松症的发生频率没有显着差异，肾结石,胃肠道疾病和低能量骨折。
