Fasting urinary calcium/creatinine and hydroxyproline/creatinine values in young women with amenorrhoea and in matched eumenorrhoeic controls.

The present study was undertaken to compare fasting urinary calcium/creatinine (Ca/Cr) and hydroxyproline/creatinine (HP/Cr) values in young amenorrhoeic women with those of age and weight-matched menstruating women and to see whether restoration of menstruation would influence values. Thirty amenorrhoeic patients were matched with 30 controls. Higher Ca/Cr (0.393 (SD 0.213) vs 0.142 (0.89), p less than 0.001) and HP/Cr (0.025 (0.005) vs 0.020 (0.007), p less than 0.005) values were found in patients with hyperprolactinaemia or hypothalamic dysfunction associated with weight loss, anorexia nervosa or excessive exercise (n = 20), suggesting excessive bone loss in these amenorrhoeic patients, who are frequently oestrogen deficient. Furthermore when 9 amenorrhoeic patients with hypothalamic dysfunction became eumenorrhoeic their urinary Ca/Cr values fell (p less than 0.02). However, amenorrhoeic patients with polycystic ovaries (n = 10) had similar Ca/Cr and HP/Cr values as their controls. It is therefore probable that amenorrhoeic patients with polycystic ovaries are not at risk of osteopenia. The present findings suggest measurements of fasting urinary Ca/Cr and HP/Cr values are likely to prove useful in identifying patients with amenorrhoea who are rapidly losing bone, and in assessing their responses to therapy.