Brief Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Feb 14, 2011; 17(6): 779-783
Published online Feb 14, 2011. doi: 10.3748/wjg.v17.i6.779
Serum magnesium concentration in children with functional constipation treated with magnesium oxide
Maiko Tatsuki, Reiko Miyazawa, Takeshi Tomomasa, Takashi Ishige, Tomoko Nakazawa, Hirokazu Arakawa
Maiko Tatsuki, Reiko Miyazawa, Takashi Ishige, Tomoko Nakazawa, Hirokazu Arakawa, Department of Pediatrics, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
Takeshi Tomomasa, PAL Clinic, 694 Tanakajima-machi, Isesaki, Gunma 372-0802, Japan
Author contributions: Tatsuki M and Miyazawa R performed the majority of the study and wrote the manuscript; Tomomasa T and Arakawa H designed the study; Ishige T and Nakazawa T collected and provided subjects’ data.
Correspondence to: Dr. Reiko Miyazawa, Department of Pediatrics, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
Telephone: +81-27-2208200 Fax: +81-27-2208215
Received: September 26, 2010
Revised: December 1, 2010
Accepted: December 8, 2010
Published online: February 14, 2011

AIM: To determine whether hypermagnesemia recently reported in adult patients possibly develops in children with functional constipation taking daily magnesium oxide.

METHODS: We enrolled 120 patients (57 male and 63 female) aged 1-14 years old (median: 4.7 years) with functional constipation from 13 hospitals and two private clinics. All patients fulfilled the Rome III criteria for functional constipation and were treated with daily oral magnesium oxide for at least 1 mo. The median treatment dose was 600 (500-800) mg/d. Patients were assessed by an interview and laboratory examination to determine possible hypermagnesemia. Serum magnesium concentration was also measured in sex- and age-matched control subjects (n = 38).

RESULTS: In the constipation group, serum magnesium concentration [2.4 (2.3-2.5) mg/dL, median and interquartile range] was significantly greater than that of the control group [2.2 (2.0-2.2) mg/dL] (P < 0.001). The highest value was 3.2 mg/dL. Renal magnesium clearance was significantly increased in the constipation group. Serum magnesium concentration in the constipation group decreased significantly with age (P < 0.01). There was no significant correlation between the serum level of magnesium and the duration of treatment with magnesium oxide or the daily dose. None of the patients had side effects associated with hypermagnesemia.

CONCLUSION: Serum magnesium concentration increased significantly, but not critically, after daily treatment with magnesium oxide in constipated children with normal renal function.

Keywords: Children, Constipation, Hypermagnesemia, Magnesium oxide, Renal dysfunction