title: Interrelationships between urinary sodium, calcium, hydroxyproline and serum PTH in healthy subjects.
abstract: The effect of sodium intake on the excretion of calcium, hydroxyproline (OHP) and serum parathyroid hormone (PTH) was examined. When seven healthy males increased their sodium intake by 200 mmol/day, excretion of calcium increased by 1.70 mmol/day and that of OHP by 27%. Serum PTH, however, did not increase significantly. In a cross-sectional study of 334 healthy female subjects there were strong positive correlations between fasting urinary sodium/creatinine (Na/Cr) and calcium/creatinine (Ca/Cr) ratios (r = 0.573) and between Na/Cr and urinary OHP/Cr ratios (r = 0.246). Serum PTH was negatively correlated with Na/Cr ratio (r = -0.161). We conclude that an increase in dietary sodium causes calciuria and an increase in hydroxyproline excretion. The results do not support the hypothesis that this is mediated by PTH.
authors.affiliation: Department of Chemical Pathology, Chinese University of Hong Kong, Shatin, New Territories.
authors.forename: E L
authors.initials: EL
authors.lastname: Chan
authors.forename: C S
authors.initials: CS
authors.lastname: Ho
authors.forename: D
authors.initials: D
authors.lastname: MacDonald
authors.forename: S C
authors.initials: SC
authors.lastname: Ho
authors.forename: T Y
authors.initials: TY
authors.lastname: Chan
authors.forename: R
authors.initials: R
authors.lastname: Swaminathan
mesh_terms: D000328:Adult; D002118:Calcium / Q000652:urine*; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006909:Hydroxyproline / Q000652:urine*; D008297:Male; D009318:Natriuresis; D010281:Parathyroid Hormone / Q000097:blood*; D012016:Reference Values
chemical_list: D010281:Parathyroid Hormone; D003404:Creatinine; D006909:Hydroxyproline; D002118:Calcium