title: High Dietary Sodium Intake Assessed by 24-hour Urine Specimen Increase Urinary Calcium Excretion and Bone Resorption Marker.
abstract: BACKGROUND
  The average dietary sodium intake of Koreans is 2.6 times higher than the World Health Organization's recommended amount. The effect of a diet high in sodium on the skeletal system, especially osteoporosis, has not previously been examined in Korean postmenopausal women with low bone mass. We assessed the daily sodium intake, and determined the impact of sodium intake on urinary calcium excretion and bone resorption marker.
  
  
  METHODS
  A retrospective review of medical records was performed for 86 postmenopausal subjects who were initially diagnosed with osteopenia or osteoporosis at the health promotion center. They were subsequently referred to the Division of Endocrinology and Metabolism between 2010 and 2013. All subjects completed a modified food frequency questionnaire. Twenty-four hour urine collection for sodium, calcium and creatinine excretion, and serum C-terminal telopeptides of type I collagen (CTX-I) were also obtained.
  
  
  RESULTS
  The average amount of daily sodium and calcium intake were 3,466 mg and 813 mg, respectively. Average dietary sodium intake and 24-hour urinary sodium excretion showed significant positive linear correlation (r=0.29, P=0.006). There was also a significant positive linear correlation between 24-hour urine sodium and calcium excretion (r=0.42, P<0.001); CTX-I and 24-hour urinary calcium excretion (r=0.29, P=0.007).
  
  
  CONCLUSIONS
  Excessive sodium intake assessed by 24-hour urine specimen is associated with high calcium excretion in urine. High calcium excretion is also related to increasing bone resorption marker.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Park
authors.affiliation: Health Promotion Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Jaehwan
authors.initials: J
authors.lastname: Jee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Joung
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Cho
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seo Young
authors.initials: SY
authors.lastname: Sohn
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang-Man
authors.initials: SM
authors.lastname: Jin
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyu Yeon
authors.initials: KY
authors.lastname: Hur
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sun Wook
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Chung
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Moon Kyu
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yong-Ki
authors.initials: YK
authors.lastname: Min
keywords: Bone resorption marker; Dietary sodium intake; Urinary calcium excretion; Urinary sodium excretion