[Skip to Content]
[Skip to Content Landing]
April 1991

Effect of Salt Restriction on Urine Hydroxyproline Excretion in Postmenopausal Women

Author Affiliations

From the Division of Clinical Chemistry (Drs Need, Morris, and Nordin), Institute of Medical and Veterinary Science, Adelaide, Australia; the Departments of Nutrition and Dietetics (Drs Cleghorn and De Nichilo) and Medicine (Dr Horowitz), Royal Adelaide Hospital; and the Department of Pathology (Dr Nordin), University of Adelaide.

Arch Intern Med. 1991;151(4):757-759. doi:10.1001/archinte.1991.00400040099022

Fasting calcium and hydroxyproline excretion are related to fasting sodium excretion in postmenopausal women. We postulate that calcium excretion is sodium dependent and that hydroxyproline excretion is calcium dependent. Therefore, we sought to lower urinary hydroxyproline, which is a marker of bone resorption, by lowering urinary sodium. Fasting urine samples were obtained from 59 postmenopausal women before and after 2 to 7 days of dietary salt restriction. The urinary sodium-to-creatinine ratio fell from 16 to 7; calcium to creatinine, 0.30 to 0.26; and hydroxyproline to creatinine, 18.2 to 16.8. In the 28 subjects with starting sodium-to-creatinine ratios greater than 15, the hydroxyproline-to-creatinine ratio fell from 19.6 to 16.3. Salt restriction may be one way of reducing bone resorption in postmenopausal women, particularly in those whose sodium intake is high.

(Arch Intern Med. 1991;151:757-759)