Low dose estrogen replacement therapy in early postmenopausal women effect on urinary magnesium and calcium: creatinine ratios.

The purpose of this study was to investigate whether treatment for prevention of osteoporosis by means of postmenopausal hormone replacement therapy (HRP) and daily exercise, had any effect on ratios of urinary calcium:creatinine (Ca:Cre) and magnesium:creatinine (Mg:Cre). A group of 33 early postmenopausal women (menopause onset 12-18 months previously), mean age 49.12 years, were treated during 6 months with low doses of transdermal estrogen (Estraderm TTS 25 micrograms, Ciba-Geigy) opposed by oral progestogen (Duphaston 10 mg, 10 days every month), and daily exercise (walking for 1 hour). Despite HRT's statistically significant lowering effect on Ca:Cre and Mg:Cre ratios, these returned to pretreatment levels 6 months after withdrawal from HRT. The mechanism by which HRT affects magnesiuria and calciuria is discussed.