Heubi J E, Higgins J V, Argao E A, Sierra R I, Specker B L
Division of Pediatric Gastroenterology and Nutrition, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
J Pediatr Gastroenterol Nutr. 1997 Sep;25(3):301-6. doi: 10.1097/00005176-199709000-00010.
Magnesium deficiency may contribute to the metabolic bone disease that complicates chronic cholestatic liver disease. We hypothesized that magnesium deficiency alters vitamin D metabolism by decreasing parathyroid hormone (PTH) response, resulting in decreased serum osteocalcin and decreased bone accretion.
Nine subjects, age 3-22 years, with cholestatic liver disease were evaluated with the magnesium retention test. The response of PTH, 1,25(OH)2 vitamin D, and osteocalcin to provocative stimuli and dual x-ray absorptiometry measurement of bone mineral density (BMD) of the lumbar spine were assessed. Thereafter, subjects were treated with oral magnesium supplements.
All nine subjects were magnesium depleted. Repletion with magnesium was successful in seven subjects, and required 4 to 31 (median 14) months with doses of 6 to 34 (median 11) mg/kg/day. Baseline serum PTH was significantly reduced in the cholestatic subjects compared to 15 age-matched controls. Comparison of baseline to repleted provocative testing was performed in six Mg-repleted subjects. Osteocalcin response increased significantly (p = 0.048) with repletion, while PTH response increased (p = 0.061). Lumbar spine BMD increased modestly with repletion (p = 0.093).
This preliminary report suggests that magnesium depletion is extremely common in children with chronic cholestasis. We speculate that magnesium supplementation may be warranted to forestall the progression of metabolic bone disease in chronic cholestasis.
镁缺乏可能导致代谢性骨病，这是慢性胆汁淤积性肝病的并发症。我们推测，镁缺乏通过降低甲状旁腺激素（PTH）反应来改变维生素D代谢，导致血清骨钙素降低和骨量增加减少。
对9名年龄在3至22岁之间的胆汁淤积性肝病患者进行镁潴留试验评估。评估了PTH、1,25(OH)2维生素D和骨钙素对刺激性刺激的反应以及腰椎骨密度（BMD）的双能X线吸收法测量。此后，对患者进行口服镁补充剂治疗。
所有9名受试者均存在镁缺乏。7名受试者成功补充了镁，补充时间为4至31个月（中位数14个月），剂量为6至34 mg/kg/天（中位数11 mg/kg/天）。与15名年龄匹配的对照组相比，胆汁淤积性患者的基线血清PTH显著降低。对6名镁补充成功的受试者进行了基线与补充后刺激性测试的比较。补充后骨钙素反应显著增加（p = 0.048），而PTH反应增加（p = 0.061）。腰椎骨密度补充后略有增加（p = 0.093）。
这份初步报告表明，镁缺乏在慢性胆汁淤积患儿中极为常见。我们推测，补充镁可能有助于预防慢性胆汁淤积中代谢性骨病的进展。
