Role of persistent amenorrhea in bone mineral metabolism of young hemodialyzed women

Background. Chronic renal failure in women is frequently associated with endocrine disturbances leading to menstrual disorders. However, most studies on renal osteodystrophy have not taken into account the possible role of these hormonal disturbances on the pathogenesis of bone alterations seen in these patients. In the present study, we evaluated bone mineral metabolism in a group of young hemodialyzed women with persistent amenorrhea and compared them with similar women with regular menstruation. Methods. We studied 74 women who were further subdivided into 43 women with regular menstrual periods and 31 women with persistent amenorrhea, defined as the absence of menstrual bleeding for more than six months. In all patients, we performed a bone mineral density (BMD) analysis and simultaneously evaluated different biochemical parameters, intact parathyroid hormone (iPTH), sexual hormone determinations that included total estradiol, follicle-stimulating (FSH), and luteinizing hormone and markers of bone resorption such as the procollagen type 1 cross-linked carboxy-terminal telopeptide (ICTP). Results. Serum calcium, phosphorus, and iPTH were similar in both groups. Serum alkaline phosphatase was higher in amenorrheic women. Although the total serum estradiol concentration was normal in the amenorrheic women when compared with nonuremic women, the values were significantly lower than those in regularly menstruating women. Serum FSH and ICTP values were significantly higher in the amenorrheic women. Trabecular BMD in the lumbar spine was also significantly lower in the amenorrheic women compared with regularly menstruating dialysis patients. Lumbar spine BMD and total estradiol levels correlated significantly in the amenorrheic group. Conclusions. These studies show that persistent amenorrheic young women on dialysis have lower trabecular BMD and evidence of increased bone resorption when compared with normal menstruating women on dialysis. The possible impact of these results in the natural history of the uremic osteodystrophy remains to be determined.