Schwarz P, Sørensen H A, Momsen G, Friis T, Transbøl I, McNair P
Department of Clinical Chemistry, University of Copenhagen.
Acta Endocrinol (Copenh). 1992 Mar;126(3):260-3. doi: 10.1530/acta.0.1260260.
The aim of this study was to elucidate the diabetic hypocalcemia and PTH responsiveness, investigated by measuring blood ionized calcium and serum intact parathyroid hormone (S-PTH(1-84)) concentrations, before and during an induced and maintained controlled hypocalcemia. In 15 patients with insulin-dependent diabetes mellitus and 19 healthy volunteers the blood ionized calcium concentration was lowered by about 0.20 mmol/l and maintained at this level by blood ionized calcium controlled tri-sodium-citrate infusion. In patients vs controls, baseline measurements averaged for blood ionized calcium (mmol/l) 1.18 +/- 0.08 vs 1.24 +/- 0.03 (p less than 0.01), for S-magnesium (mmol/l) 0.73 +/- 0.07 vs 0.81 +/- 0.07 (p less than 0.01) and for S-PTH (1-84) (pmol/l) 3.0 +/- 1.0 vs 3.1 +/- 1.0 (p greater than 0.75). During the clamp, S-PTH (1-84) peaked to comparable maximums after 5-10 min in both groups and then declined to constant concentrations two to three times above their control levels. In conclusion, we found a diabetic hypocalcemia and hypomagnesemia, though baseline levels of PTH and PTH responsiveness were normal. This may be taken to indicate a mild shift downwards in the set-point for PTH secretion in patients with insulin-dependent diabetes mellitus.
本研究的目的是通过测量诱导并维持的可控性低钙血症发生前及过程中的血离子钙和血清完整甲状旁腺激素（S-PTH(1-84)）浓度，来阐明糖尿病患者的低钙血症及甲状旁腺激素反应性。在15例胰岛素依赖型糖尿病患者和19名健康志愿者中，通过输注离子钙可控的枸橼酸钠使血离子钙浓度降低约0.20 mmol/l并维持在此水平。患者组与对照组相比，血离子钙（mmol/l）的基线测量平均值分别为1.18±0.08和1.24±0.03（p<0.01），血清镁（mmol/l）分别为0.73±0.07和0.81±0.07（p<0.01），S-PTH(1-84)（pmol/l）分别为3.0±1.0和3.1±1.0（p>0.75）。在钳夹过程中，两组的S-PTH(1-84)在5-10分钟后均达到相当的峰值，然后下降至比对照水平高两到三倍的稳定浓度。总之，我们发现糖尿病患者存在低钙血症和低镁血症，尽管甲状旁腺激素的基线水平和反应性正常。这可能表明胰岛素依赖型糖尿病患者甲状旁腺激素分泌的设定点有轻度下移。
