本帖最後由 lsc0019 於 2009-8-12 22:31 編輯
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
July 27, 2009 — 根據一項於7月13日線上發表於小兒科醫學期刊的研究結果，口服檸檬酸鉀可能協助預防接受生酮飲食的兒童發生腎結石。
馬里蘭巴爾的摩約翰霍普金斯大學醫學院的Melanie A. McNally學士寫到，接受生酮飲食的兒童中，約有6%發生腎結石。檸檬酸鉀（Polycitra K，Cypress藥廠）是一種每天使用、可以鹼化尿液且使尿中鈣溶出的口服補充液，理論上可以降低腎結石風險。
這項研究樣本包括313位於2000年至2008年間開始於約翰霍普金斯醫院食用生酮飲食的兒童，這些兒童至少接受一個月以上的後續追蹤。符合每天使用檸檬酸鉀的適應症，2000年至2005年間，接受生酮飲食發生高尿鈣的兒童，這些兒童接受每天每公斤2 mEq的劑量。從2006年後，所有接受生酮飲食的兒童都經驗性地使用檸檬酸鉀。
198位使用檸檬酸鉀預防的兒童中有4位（2.0%），105位沒有使用檸檬酸鉀的兒童有11位（10.5%）發生腎結石（P=0.003）。從2006年開始，2位兒童拒絕補充檸檬酸鉀；這2位兒童中有1位發生腎結石。在開始使用生酮飲食時，成功接受預防性檸檬酸鉀的兒童，腎結石的發生率為0.9%（1/106），因為高尿鈣才接受檸檬酸鉀的兒童則是6.7%（13/195）。
雖然接受檸檬酸鉀的兒童尿液比較偏鹼性（平均pH值為6.8相較於6.2；P=0.002），但這一組的血液酸鹼值並未下降。檸檬酸鉀的耐受性良好，且無顯著副作用。
研究作者們寫到，口服檸檬酸鉀對接受生酮飲食的兒童而言，是個有效預防腎結石的補充品，可以達到鹼化尿液的目標，值得全面補充。
這項研究的限制包括缺乏隨機分派。
研究作者們的結論是，我們建議開始使用生酮飲食時教育有關於常規補充Polycitra K的重要性，之後要在每次就診時強調其重要性。更多的研究將有助於確認高劑量Polycitra K是否可以完全地預防或是可以與其他補充品合併使用，例如複方維他命，來增加順應性。
兒童臨床研究單位、國家衛生研究院/國家癌症研究資源以及Carson Harris基金會贊助這項研究。研究作者們表示沒有相關資金上的往來。
Oral Potassium Citrate May Help Prevent Kidney Stones in Children on the Ketogenic Diet
By Laurie Barclay, MD
Medscape Medical News
July 27, 2009 — Oral potassium citrate supplementation may help prevent kidney stones in children who receive the ketogenic diet, according to the results of a study reported online July 13 in Pediatrics.
"Kidney stones occur in 6% of children who receive the KD," write Melanie A. McNally, BS, from the School of Medicine, Johns Hopkins University in Baltimore, Maryland, and colleagues. "Potassium citrate (Polycitra K [Cypress Pharmaceuticals]) is a daily oral supplement that alkalinizes the urine and solubilizes urine calcium, theoretically reducing the risk for kidney stones."
The study sample consisted of 313 children who started the ketogenic diet from 2000 to 2008 at Johns Hopkins Hospital and who had at least 1 month of follow-up. Indications for use of daily potassium citrate, 2 mEq/kg/day, were only in the setting of identified hypercalciuria for children receiving the ketogenic diet from 2000 to 2005. Since 2006, daily potassium citrate was administered empirically to all children receiving the ketogenic diet.
Kidney stones developed in 4 (2.0%) of 198 children who received potassium citrate preventatively and in 11 (10.5%) of 105 children who did not receive potassium citrate (P = .003). Since 2006, 2 children refused supplementation with potassium citrate; of these 2, a kidney stone developed in 1 child. Incidence of kidney-stones was 0.9% (1/106) in those receiving successful empiric administration of potassium citrate at onset of the ketogenic diet vs 6.7% (13/195) in those given potassium citrate only because of hypercalciuria (P = .02).
Although children who received potassium citrate had less acidic urine (mean pH, 6.8 vs 6.2; P = .002), serum acidosis was not reduced in this group. Potassium citrate was well tolerated with no apparent adverse effects.
"Oral potassium citrate is an effective preventive supplement against kidney stones in children who receive the KD [ketogenic diet], achieving its goal of urine alkalinization," the study authors write. "Universal supplementation is warranted."
Limitations of this study include lack of randomization.
"We advise initial education about the importance of regular Polycitra K use at the time of KD onset and subsequent reinforcement at each follow-up clinic," the study authors conclude. "Additional studies may help to determine whether higher dosages of Polycitra K would be completely preventive or could perhaps be combined with other supplements such as multivitamins to aid compliance."
The Pediatric Clinical Research Unit, National Institutes of Health/National Center for Research Resources and the Carson Harris Foundation supported this study. The study authors have disclosed no relevant financial relationships.
Pediatrics. Published online July 13, 2009. |
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