Evaluation of serum estradiol, intact parathyroid hormone, and interleukin-6 levels in relation to bone mineral density in postmenopausal women

Abstract EN

Background Osteoporosis is a disorder characterized by a reduction in the quantity of bone during aging without changes in its chemical composition.

Increased bone turnover in women after menopause has been generally explained by two different mechanisms, first it has been assumed that there is an initial rapid phase of estrogen dependent bone turnover during early post menopause, and a later phase of increased bone turnover in older age. Aim : the work aimed at studying the serum levels of interleukin-6, intact parathyroid hormone and estradiol in postmenopausal females and their possible role in bone changes in such cases. Methods : the study was conducted on fifty female subjects.

Thirty postmenopausal women with radiological evidence of bony changes (osteopenia and osteoporotic) were compared to a group of twenty apparently healthy young non-pregnant females.

Bone densitometry was done using Dual X-ray absorptiometry (DXA).

Laboratory investigations were done including determination of serum levels of intact parathyroid hormone (IPTH), estradiol and interleukin–6 (IL-6) as one of the cytokines involved in skeletal remodeling. Results: serum estradiol level was significantly lower in the postmenopausal females than the corresponding control group and again significantly lower in the osteoporotic group than the osteopenia group.

Serum estradiol level was negatively correlated with the duration of menopause and positively correlated with the bone mineral density.

On the other hand, the serum levels of both IPTH and IL-6 were significantly higher in the postmenopausal females than the corresponding control group and again significantly higher in the osteoporotic group than the osteopenia group.

Serum IPTH and IL-6 were positively correlated with each other and with the duration of menopause and negatively correlated with the bone mineral density. Conclusion : it could be concluded that IL-6 might play a role in increasing the skeletal sensitivity to the resorbing action of PTH seen in estrogen deficient postmenopausal women.