a1 Department of Metabolism and Nutrition, Instituto del Frío, Spanish Council for Scientific Research (CSIC), C/José Antonio Novais 10, 28040-Madrid, Spain
a2 Department of Nutrition, Faculty of Pharmacy, Madrid Complutense University, Madrid, Spain
a3 Laboratory of Bone Pathophysiology, Fundación Jimenez Díaz, Madrid, Spain
This study was designed to investigate the possible effects of consuming Na-rich carbonated mineral water on bone remodelling and urinary mineral excretion in postmenopausal women. Women (n 18) included were amenorrhoeic (>1 year), healthy and not obese (BMI <30 kg/m2). No woman was taking oestrogen replacement therapy, mineral and vitamin supplements, phyto-oestrogens or medications known to affect bone and lipid metabolism. In two consecutive interventions that lasted 8 weeks each, women drank 1 litre of control mineral water daily and 1 litre of carbonated mineral water, rich in Na, HCO–3 inf super and Cl−, daily. Body weight and height were measured, BMI was calculated and blood pressure was measured. Blood samples were taken from fasting subjects and serum obtained to analyse the biochemical bone markers, procollagen I amino-terminal propeptide (PINP) and β-carboxy-terminal telopeptide of collagen (β-CTX). At the end of each period, 24 h urine samples were collected to determine Ca, Mg, P, Na+, K+, Cl−, urine excretion and urinary pH. No changes in body weight, BMI or blood pressure were observed during the experimental period. Ca excretion was lower after the intake of carbonated water than after intake of the control water (P=0·037) while P excretion was higher (P=0·015). Total urine, Na and Cl− excretion did not differ between the two periods but urinary pH was increased after the intake of carbonated mineral water. PINP and β-CTX did not differ between the two periods. Daily consumption of 1 litre of Na-rich carbonated mineral water for 8 weeks does not affect bone remodelling in healthy postmenopausal women.
(Received June 03 2004)
(Revised September 20 2004)
(Accepted October 18 2004)