LUMBAR AND FEMORAL BONE-DENSITY IN PERIMENOPAUSAL WOMEN WITH IRREGULAR CYCLES

Objective - The aim of the study was to evaluate the impact of irregul ar cycles on bone mass in perimenopausal women. Setting - University c linic. Patients and Methods - 118 healthy women aged between 45 and 55 years were divided into three groups according to the previous year's menstrual history (premenopause: regular cycles; perimenopause: irreg ular cycles; early postmenopause: 1-3 years since the last menstrual c ycle). Among the perimenopausal group, only women presenting intervals without menstruation longer than 3 months during the year of the stud y were selected. Bone mineral density of the lumbar spine and of the p roximal femur was measured by dual energy X-ray absorptiometry (DEXA) at the start of the study and after 12 months. Results - The serum est radiol level was significantly lower in postmenopausal women and the F SH serum level showed a significant increase in perimenopausal and pos tmenopausal women in comparison with premenopausal controls. Bone dens ity at L(2)-L(4), femoral neck, greater trochanter, and total femur di d not show significant differences at the beginning of the between-gro up study. Only the density in Ward's triangle was significantly lower in perimenopausal and postmenopausal women. After twelve months the de nsities of L(2)-L(4), greater trochanter, Ward's triangle, and total f emur showed a significant decrease in postmenopausal women in comparis on. The perimenopausal group showed a significant decrease in total fe mur and Ward's triangle density in comparison with premenopausal. Conc lusion - The occurrence of marked irregularity of menstrual cycles pre ceding menopause can influence bone mass, in particular at the femoral site.