Bergenfelz A, Valdermarsson S, Ahrén B
Department of Surgery, Lund University, Sweden.
Horm Res. 1993;39(3-4):146-51. doi: 10.1159/000182715.
Primary hyperparathyroidism (pHPT) is associated with a right-shifted relation between parathyroid hormone (PTH) secretion and calcium. However, it is also possible that a decreased suppressibility of PTH secretion by calcium is important for maintaining hypercalcemia in pHPT. We therefore compared the suppression of serum levels of intact PTH induced by a 1.5-gram oral calcium load in patients with mild pHPT with that in healthy subjects. The calcemic response to the oral calcium load was the same in the two groups and did not correlate with the degree of PTH suppression or to serum levels of vitamin D metabolites. It was found that serum levels of intact PTH were less suppressed by the oral calcium load in patients than in healthy subjects (p < 0.01), but with a considerable overlap between the two groups. The suppression of serum levels of intact PTH was correlated both to baseline serum total calcium levels (r = -0.55; p < 0.05) and osteocalcin levels (r = -0.69; p < 0.05) in the patients, but no such correlations were seen in the controls. We conclude that patients with pHPT have a decreased suppressibility of PTH secretion by calcium. Although this reduced suppressibility could be important for maintaining hypercalcemia in some patients with pHPT, it does not aid in the differential diagnosis between patients with mild pHPT and healthy subjects.
原发性甲状旁腺功能亢进症（pHPT）与甲状旁腺激素（PTH）分泌和钙之间的关系右移有关。然而，钙对PTH分泌的抑制性降低对于维持pHPT患者的高钙血症也可能很重要。因此，我们比较了轻度pHPT患者与健康受试者口服1.5克钙负荷后血清中完整PTH水平的抑制情况。两组对口服钙负荷的血钙反应相同，且与PTH抑制程度或维生素D代谢产物的血清水平无关。结果发现，与健康受试者相比，患者口服钙负荷后血清中完整PTH水平的抑制作用较小（p < 0.01），但两组之间有相当大的重叠。患者血清中完整PTH水平的抑制与基线血清总钙水平（r = -0.55；p < 0.05）和骨钙素水平（r = -0.69；p < 0.05）均相关，但在对照组中未观察到此类相关性。我们得出结论，pHPT患者钙对PTH分泌的抑制性降低。尽管这种降低的抑制性可能对某些pHPT患者维持高钙血症很重要，但它无助于轻度pHPT患者与健康受试者之间的鉴别诊断。
