BONE-MINERAL DENSITY OF THE LUMBAR SPINE IN ENDOMETRIOSIS SUBJECTS COMPARED TO AN AGE-SIMILAR CONTROL POPULATION

The purpose of this study was to compare the lumbar bone mineral density (BMD) between women with endometriosis and age-similar controls. Eighty-five women from nine North American centers (mean age, 30.7 yr) with laparoscopically proven endometriosis (study patients) were enrolled in a study of the efficacy of nafarelin, a GnRH agonist. Fifty-two women (mean age, 32 yr) from the Palo Alto area, with regular menstrual cycles and no major medical problems, served as age-similar controls. Both groups were predominantly (> 92%) white. The mean BMD of the lumbar spine was 1.1 g/cm2 in both the study subjects and the controls. Study patients were 104.8% and controls were 104.8% of normal values for age. BMD was not significantly different in the two groups. BMD was not correlated with severity or time from diagnosis of endometriosis. BMD was positively correlated with weight (r = 0.28; P < 0.05) in both groups, with height (r = 0.30; P < 0.01) in study patients, and marginally with height (r = 0.26; P < 0.07) in controls. This study showed no difference in BMD between endometriosis patients and age-similar controls; both groups had normal BMD.