McHenry C R, Rosen I B, Walfish P G, Pollard A
Department of Surgery, University of Toronto, Mount Sinai Hospital, Ontario, Canada.
Surgery. 1990 Dec;108(6):1026-31; discussion 1032.
An oral calcium load test (CLT) (1 gm Ca/50 kg) was administered to 11 control subjects and 35 patients with overt hyperparathyroidism to assess its efficacy in diagnosis of hyperparathyroidism. All participants were placed on a low-calcium diet 3 days before the CLT. Intact parathormone and ionized calcium (Cai) levels were measured 0, 1, 2, and 3 hours after CLT. Initial Cai and parathormone (mean +/- SE) were 1.22 +/- 0.01 mmol/L and 2.94 +/- 0.03 pmol/L in the control group compared with 1.43 +/- 0.02 mmol/L and 10.6 +/- 2.2 pmol/L in the group with hyperparathyroidism. Both groups had a similar percent increase in Cai values (control, 5.9% +/- 0.8%; hyperparathyroidism, 6.3% +/- 0.6% (p greater than 0.1). A decline in parathormone levels of 47.6% +/- 2.8% in patients with hyperparathyroidism was significantly less than the 75.3% +/- 5.3% decline observed in control subjects (p less than 0.025). Three hours after CLT, parathormone was suppressed in control subjects, whereas a rebound occurred in patients with hyperparathyroidism. Postoperative CLT demonstrated a higher mean percent Cai increase and percent parathormone decline (Cai, 8.9% +/- 1.1%; parathormone, 67.9% +/- 1.8%) compared with preoperative values (Cai, 6.0% +/- 1.0%; PTH, 49.6% +/- 4.3%) (p less than 0.025), and 3 hours after calcium intake, parathormone remained suppressed, similar to control subjects. After surgery, three patients had elevated parathormone and low normal Cai levels and parathormone response to a CLT confirmed the diagnosis of secondary hyperparathyroidism. In conclusion, a CLT (1) can confirm the diagnosis of hyperparathyroidism and successful parathyroidectomy, (2) distinguished postoperative secondary from persistent primary hyperparathyroidism, (3) demonstrated nonautonomy of abnormal parathyroid glands with a parathormone response to a calcium load characterized by an earlier nadir, decreased suppressibility, and more rapid recovery, and (4) produced dynamic changes that did not distinguish patients with hyperparathyroidism from control subjects or hyperplasia from adenoma.
对11名对照受试者和35名明显甲状旁腺功能亢进患者进行了口服钙负荷试验（CLT）（1克钙/50千克体重），以评估其在诊断甲状旁腺功能亢进中的效果。所有参与者在CLT前3天采用低钙饮食。在CLT后0、1、2和3小时测量完整甲状旁腺激素和离子钙（Cai）水平。对照组初始Cai和甲状旁腺激素（平均值±标准误）分别为1.22±0.01毫摩尔/升和2.94±0.03皮摩尔/升，而甲状旁腺功能亢进组分别为1.43±0.02毫摩尔/升和10.6±2.2皮摩尔/升。两组Cai值的百分比升高相似（对照组为5.9%±0.8%；甲状旁腺功能亢进组为6.3%±0.6%（p＞0.1））。甲状旁腺功能亢进患者甲状旁腺激素水平下降47.6%±2.8%，显著低于对照组观察到的75.3%±5.3%的下降幅度（p＜0.025）。CLT后3小时，对照组甲状旁腺激素受到抑制，而甲状旁腺功能亢进患者出现反弹。术后CLT显示，与术前值（Cai为6.0%±1.0%；甲状旁腺激素为49.6%±4.3%）相比，Cai平均百分比升高和甲状旁腺激素百分比下降更高（Cai为8.9%±1.1%；甲状旁腺激素为67.9%±1.8%）（p＜0.025），且钙摄入后3小时，甲状旁腺激素仍受到抑制，与对照组相似。术后，3例患者甲状旁腺激素升高且Cai水平略低于正常，甲状旁腺激素对CLT的反应证实了继发性甲状旁腺功能亢进的诊断。总之，CLT（1）可确诊甲状旁腺功能亢进和甲状旁腺切除术成功，（2）区分术后继发性与持续性原发性甲状旁腺功能亢进，（3）通过甲状旁腺激素对钙负荷的反应表现为更早的最低点、更低的抑制性和更快的恢复，证明异常甲状旁腺无自主性，（4）产生的动态变化无法区分甲状旁腺功能亢进患者与对照受试者，也无法区分增生与腺瘤。
