A longitudinal evaluation of bone mineral density (BMD) and metabolism
was performed in premenopausal women. During the 2-year observation p
eriod, the menstrual pattern, plasma estradiol and FSH levels as well
as the values of bone markers and BMD did not show any significant mod
ification in a group of eumenorrhoic women (n = 37). Conversely, in ag
e-matched oligomenorrhoic women (n = 37) a significant (P < 0.05) incr
ease in the cycle length with a concomitant significant (P < 0.05) inc
rease in circulating plasma FSH and parallel decrease of plasma estrad
iol levels (P < 0.05) was evident. In this group a significant (P < 0.
05) increase in both urinary excretion of OH-P/Cr and plasma BGP level
s paralleled a significant (P < 0.05) decrease in radial BMD. These da
ta suggest that premenopausal impairment of ovarian function can lead
to a bone loss in a significant proportion of women in which preventio
n should be considered before menopause.